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<li class="nav-item nav-item-0"><a href="../index.html">Evennia 1.0-dev</a> &#187;</li>
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<div class="section" id="evmenu">
<h1>EvMenu<a class="headerlink" href="#evmenu" title="Permalink to this headline"></a></h1>
<div class="section" id="introduction">
<h2>Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline"></a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> utility class is located in
<a class="reference external" href="https://github.com/evennia/evennia/blob/master/evennia/utils/evmenu.py">evennia/utils/evmenu.py</a>.
It allows for easily adding interactive menus to the game; for example to implement Character
creation, building commands or similar. Below is an example of offering NPC conversation choices:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">The</span> <span class="n">guard</span> <span class="n">looks</span> <span class="n">at</span> <span class="n">you</span> <span class="n">suspiciously</span><span class="o">.</span>
<span class="s2">&quot;No one is supposed to be in here ...&quot;</span>
<span class="n">he</span> <span class="n">says</span><span class="p">,</span> <span class="n">a</span> <span class="n">hand</span> <span class="n">on</span> <span class="n">his</span> <span class="n">weapon</span><span class="o">.</span>
<span class="n">_______________________________________________</span>
<span class="mf">1.</span> <span class="n">Try</span> <span class="n">to</span> <span class="n">bribe</span> <span class="n">him</span> <span class="p">[</span><span class="n">Cha</span> <span class="o">+</span> <span class="mi">10</span> <span class="n">gold</span><span class="p">]</span>
<span class="mf">2.</span> <span class="n">Convince</span> <span class="n">him</span> <span class="n">you</span> <span class="n">work</span> <span class="n">here</span> <span class="p">[</span><span class="n">Int</span><span class="p">]</span>
<span class="mf">3.</span> <span class="n">Appeal</span> <span class="n">to</span> <span class="n">his</span> <span class="n">vanity</span> <span class="p">[</span><span class="n">Cha</span><span class="p">]</span>
<span class="mf">4.</span> <span class="n">Try</span> <span class="n">to</span> <span class="n">knock</span> <span class="n">him</span> <span class="n">out</span> <span class="p">[</span><span class="n">Luck</span> <span class="o">+</span> <span class="n">Dex</span><span class="p">]</span>
<span class="mf">5.</span> <span class="n">Try</span> <span class="n">to</span> <span class="n">run</span> <span class="n">away</span> <span class="p">[</span><span class="n">Dex</span><span class="p">]</span>
</pre></div>
</div>
<p>This is an example of a menu <em>node</em>. Think of a node as a point where the menu stops printing text
and waits for user to give some input. By jumping to different nodes depending on the input, a menu
is constructed.</p>
<p>To create the menu, EvMenu uses normal Python functions, one per node. It will load all those
functions/nodes either from a module or by being passed a dictionary mapping the node’s names to
said functions, like <code class="docutils literal notranslate"><span class="pre">{&quot;nodename&quot;:</span> <span class="pre">&lt;function&gt;,</span> <span class="pre">...}</span></code></p>
</div>
<div class="section" id="launching-the-menu">
<h2>Launching the menu<a class="headerlink" href="#launching-the-menu" title="Permalink to this headline"></a></h2>
<p>Initializing the menu is done using a call to the <code class="docutils literal notranslate"><span class="pre">evennia.utils.evmenu.EvMenu</span></code> class. This is the
most common way to do so - from inside a <a class="reference internal" href="Commands.html"><span class="doc">Command</span></a>:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="c1"># in, for example gamedir/commands/command.py</span>
<span class="kn">from</span> <span class="nn">evennia.utils.evmenu</span> <span class="kn">import</span> <span class="n">EvMenu</span>
<span class="k">class</span> <span class="nc">CmdTestMenu</span><span class="p">(</span><span class="n">Command</span><span class="p">):</span>
<span class="n">key</span> <span class="o">=</span> <span class="s2">&quot;testcommand&quot;</span>
<span class="k">def</span> <span class="nf">func</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">EvMenu</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="s2">&quot;world.mymenu&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>When running this command, the menu will start using the menu nodes loaded from
<code class="docutils literal notranslate"><span class="pre">mygame/world/mymenu.py</span></code>. See next section on how to define menu nodes.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> has the following optional callsign:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="n">EvMenu</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">menu_data</span><span class="p">,</span>
<span class="n">startnode</span><span class="o">=</span><span class="s2">&quot;start&quot;</span><span class="p">,</span>
<span class="n">cmdset_mergetype</span><span class="o">=</span><span class="s2">&quot;Replace&quot;</span><span class="p">,</span> <span class="n">cmdset_priority</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span>
<span class="n">auto_quit</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span> <span class="n">auto_look</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span> <span class="n">auto_help</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span>
<span class="n">cmd_on_exit</span><span class="o">=</span><span class="s2">&quot;look&quot;</span><span class="p">,</span>
<span class="n">persistent</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span>
<span class="n">startnode_input</span><span class="o">=</span><span class="s2">&quot;&quot;</span><span class="p">,</span>
<span class="n">session</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span>
<span class="n">debug</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span>
<span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">caller</span></code> (Object or Account): is a reference to the object using the menu. This object will get a
new <a class="reference internal" href="Command-Sets.html"><span class="doc">CmdSet</span></a> assigned to it, for handling the menu.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">menu_data</span></code> (str, module or dict): is a module or python path to a module where the global-level
functions will each be considered to be a menu node. Their names in the module will be the names
by which they are referred to in the module. Importantly, function names starting with an
underscore
<code class="docutils literal notranslate"><span class="pre">_</span></code> will be ignored by the loader. Alternatively, this can be a direct mapping
<code class="docutils literal notranslate"><span class="pre">{&quot;nodename&quot;:function,</span> <span class="pre">...}</span></code>.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">startnode</span></code> (str): is the name of the menu-node to start the menu at. Changing this means that
you can jump into a menu tree at different positions depending on circumstance and thus possibly
re-use menu entries.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">cmdset_mergetype</span></code> (str): This is usually one of “Replace” or “Union” (see [CmdSets](Command-
Sets).
The first means that the menu is exclusive - the user has no access to any other commands while
in the menu. The Union mergetype means the menu co-exists with previous commands (and may
overload
them, so be careful as to what to name your menu entries in this case).</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">cmdset_priority</span></code> (int): The priority with which to merge in the menu cmdset. This allows for
advanced usage.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">auto_quit</span></code>, <code class="docutils literal notranslate"><span class="pre">auto_look</span></code>, <code class="docutils literal notranslate"><span class="pre">auto_help</span></code> (bool): If either of these are <code class="docutils literal notranslate"><span class="pre">True</span></code>, the menu
automatically makes a <code class="docutils literal notranslate"><span class="pre">quit</span></code>, <code class="docutils literal notranslate"><span class="pre">look</span></code> or <code class="docutils literal notranslate"><span class="pre">help</span></code> command available to the user. The main reason why
you’d want to turn this off is if you want to use the aliases “q”, “l” or “h” for something in
your
menu. Nevertheless, at least <code class="docutils literal notranslate"><span class="pre">quit</span></code> is highly recommend - if <code class="docutils literal notranslate"><span class="pre">False</span></code>, the menu <em>must</em> itself
supply
an “exit node” (a node without any options), or the user will be stuck in the menu until the
server
reloads (or eternally if the menu is <code class="docutils literal notranslate"><span class="pre">persistent</span></code>)!</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">cmd_on_exit</span></code> (str): This command string will be executed right <em>after</em> the menu has closed down.
From experience, it’s useful to trigger a “look” command to make sure the user is aware of the
change of state; but any command can be used. If set to <code class="docutils literal notranslate"><span class="pre">None</span></code>, no command will be triggered
after
exiting the menu.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">persistent</span></code> (bool) - if <code class="docutils literal notranslate"><span class="pre">True</span></code>, the menu will survive a reload (so the user will not be kicked
out by the reload - make sure they can exit on their own!)</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">startnode_input</span></code> (str or (str, dict) tuple): Pass an input text or a input text + kwargs to the
start node as if it was entered on a fictional previous node. This can be very useful in order to
start a menu differently depending on the Command’s arguments in which it was initialized.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">session</span></code> (Session): Useful when calling the menu from an <a class="reference internal" href="Accounts.html"><span class="doc">Account</span></a> in
<code class="docutils literal notranslate"><span class="pre">MULTISESSION_MODDE</span></code> higher than 2, to make sure only the right Session sees the menu output.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">debug</span></code> (bool): If set, the <code class="docutils literal notranslate"><span class="pre">menudebug</span></code> command will be made available in the menu. Use it to
list the current state of the menu and use <code class="docutils literal notranslate"><span class="pre">menudebug</span> <span class="pre">&lt;variable&gt;</span></code> to inspect a specific state
variable from the list.</p></li>
<li><p>All other keyword arguments will be available as initial data for the nodes. They will be
available in all nodes as properties on <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code> (see below). These will also
survive a <code class="docutils literal notranslate"><span class="pre">&#64;reload</span></code> if the menu is <code class="docutils literal notranslate"><span class="pre">persistent</span></code>.</p></li>
</ul>
<p>You don’t need to store the EvMenu instance anywhere - the very act of initializing it will store it
as <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code> on the <code class="docutils literal notranslate"><span class="pre">caller</span></code>. This object will be deleted automatically when the menu
is exited and you can also use it to store your own temporary variables for access throughout the
menu. Temporary variables you store on a persistent <code class="docutils literal notranslate"><span class="pre">_menutree</span></code> as it runs will
<em>not</em> survive a <code class="docutils literal notranslate"><span class="pre">&#64;reload</span></code>, only those you set as part of the original <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> call.</p>
</div>
<div class="section" id="the-menu-nodes">
<h2>The Menu nodes<a class="headerlink" href="#the-menu-nodes" title="Permalink to this headline"></a></h2>
<p>The EvMenu nodes consist of functions on one of these forms.</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">menunodename1</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="c1"># code</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="k">def</span> <span class="nf">menunodename2</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">):</span>
<span class="c1"># code</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="k">def</span> <span class="nf">menunodename3</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="c1"># code</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<blockquote>
<div><p>While all of the above forms are okay, it’s recommended to stick to the third and last form since
it
gives the most flexibility. The previous forms are mainly there for backwards compatibility with
existing menus from a time when EvMenu was less able.</p>
</div></blockquote>
<div class="section" id="input-arguments-to-the-node">
<h3>Input arguments to the node<a class="headerlink" href="#input-arguments-to-the-node" title="Permalink to this headline"></a></h3>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">caller</span></code> (Object or Account): The object using the menu - usually a Character but could also be a
Session or Account depending on where the menu is used.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">raw_string</span></code> (str): If this is given, it will be set to the exact text the user entered on the
<em>previous</em> node (that is, the command entered to get to this node). On the starting-node of the
menu, this will be an empty string, unless <code class="docutils literal notranslate"><span class="pre">startnode_input</span></code> was set.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">kwargs</span></code> (dict): These extra keyword arguments are extra optional arguments passed to the node
when the user makes a choice on the <em>previous</em> node. This may include things like status flags
and details about which exact option was chosen (which can be impossible to determine from
<code class="docutils literal notranslate"><span class="pre">raw_string</span></code> alone). Just what is passed in <code class="docutils literal notranslate"><span class="pre">kwargs</span></code> is up to you when you create the previous
node.</p></li>
</ul>
</div>
<div class="section" id="return-values-from-the-node">
<h3>Return values from the node<a class="headerlink" href="#return-values-from-the-node" title="Permalink to this headline"></a></h3>
<p>Each function must return two variables, <code class="docutils literal notranslate"><span class="pre">text</span></code> and <code class="docutils literal notranslate"><span class="pre">options</span></code>.</p>
<div class="section" id="text">
<h4>text<a class="headerlink" href="#text" title="Permalink to this headline"></a></h4>
<p>The <code class="docutils literal notranslate"><span class="pre">text</span></code> variable is a string or tuple. This text is what will be displayed when the user reaches
this node. If this is a tuple, then the first element of the tuple will be considered the displayed
text and the second the help-text to display when the user enters the <code class="docutils literal notranslate"><span class="pre">help</span></code> command on this node.</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1</pre></div></td><td class="code"><div class="highlight"><pre><span></span> <span class="n">text</span> <span class="o">=</span> <span class="p">(</span><span class="s2">&quot;This is the text to display&quot;</span><span class="p">,</span> <span class="s2">&quot;This is the help text for this node&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>Returning a <code class="docutils literal notranslate"><span class="pre">None</span></code> text is allowed and simply leads to a node with no text and only options. If the
help text is not given, the menu will give a generic error message when using <code class="docutils literal notranslate"><span class="pre">help</span></code>.</p>
</div>
<div class="section" id="options">
<h4>options<a class="headerlink" href="#options" title="Permalink to this headline"></a></h4>
<p>The <code class="docutils literal notranslate"><span class="pre">options</span></code> list describe all the choices available to the user when viewing this node. If
<code class="docutils literal notranslate"><span class="pre">options</span></code> is
returned as <code class="docutils literal notranslate"><span class="pre">None</span></code>, it means that this node is an <em>Exit node</em> - any text is displayed and then the
menu immediately exits, running the <code class="docutils literal notranslate"><span class="pre">exit_cmd</span></code> if given.</p>
<p>Otherwise, <code class="docutils literal notranslate"><span class="pre">options</span></code> should be a list (or tuple) of dictionaries, one for each option. If only one
option is
available, a single dictionary can also be returned. This is how it could look:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11
12
13</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">node_test</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;A goblin attacks you!&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">(</span>
<span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="p">(</span><span class="s2">&quot;Attack&quot;</span><span class="p">,</span> <span class="s2">&quot;a&quot;</span><span class="p">,</span> <span class="s2">&quot;att&quot;</span><span class="p">),</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Strike the enemy with all your might&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;node_attack&quot;</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="p">(</span><span class="s2">&quot;Defend&quot;</span><span class="p">,</span> <span class="s2">&quot;d&quot;</span><span class="p">,</span> <span class="s2">&quot;def&quot;</span><span class="p">),</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Hold back and defend yourself&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="p">(</span><span class="n">_defend</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;str&quot;</span><span class="p">:</span> <span class="mi">10</span><span class="p">,</span> <span class="s2">&quot;enemyname&quot;</span><span class="p">:</span> <span class="s2">&quot;Goblin&quot;</span><span class="p">})})</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>This will produce a menu node looking like this:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>A goblin attacks you!
________________________________
Attack: Strike the enemy with all your might
Defend: Hold back and defend yourself
</pre></div>
</div>
<div class="section" id="option-key-key">
<h5>option-key ‘key’<a class="headerlink" href="#option-key-key" title="Permalink to this headline"></a></h5>
<p>The option’s <code class="docutils literal notranslate"><span class="pre">key</span></code> is what the user should enter in order to choose that option. If given as a
tuple, the
first string of that tuple will be what is shown on-screen while the rest are aliases for picking
that option. In the above example, the user could enter “Attack” (or “attack”, it’s not
case-sensitive), “a” or “att” in order to attack the goblin. Aliasing is useful for adding custom
coloring to the choice. The first element of the aliasing tuple should then be the colored version,
followed by a version without color - since otherwise the user would have to enter the color codes
to select that choice.</p>
<p>Note that the <code class="docutils literal notranslate"><span class="pre">key</span></code> is <em>optional</em>. If no key is given, it will instead automatically be replaced
with a running number starting from <code class="docutils literal notranslate"><span class="pre">1</span></code>. If removing the <code class="docutils literal notranslate"><span class="pre">key</span></code> part of each option, the resulting
menu node would look like this instead:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>A goblin attacks you!
________________________________
1: Strike the enemy with all your might
2: Hold back and defend yourself
</pre></div>
</div>
<p>Whether you want to use a key or rely on numbers is mostly
a matter of style and the type of menu.</p>
<p>EvMenu accepts one important special <code class="docutils literal notranslate"><span class="pre">key</span></code> given only as <code class="docutils literal notranslate"><span class="pre">&quot;_default&quot;</span></code>. This key is used when a user
enters something that does not match any other fixed keys. It is particularly useful for getting
user input:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1
2
3
4
5
6
7</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">node_readuser</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Please enter your name&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;_default&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;node_parse_input&quot;</span><span class="p">}</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>A <code class="docutils literal notranslate"><span class="pre">&quot;_default&quot;</span></code> option does not show up in the menu, so the above will just be a node saying
<code class="docutils literal notranslate"><span class="pre">&quot;Please</span> <span class="pre">enter</span> <span class="pre">your</span> <span class="pre">name&quot;</span></code>. The name they entered will appear as <code class="docutils literal notranslate"><span class="pre">raw_string</span></code> in the next node.</p>
</div>
</div>
<div class="section" id="option-key-desc">
<h4>option-key ‘desc’<a class="headerlink" href="#option-key-desc" title="Permalink to this headline"></a></h4>
<p>This simply contains the description as to what happens when selecting the menu option. For
<code class="docutils literal notranslate"><span class="pre">&quot;_default&quot;</span></code> options or if the <code class="docutils literal notranslate"><span class="pre">key</span></code> is already long or descriptive, it is not strictly needed. But
usually it’s better to keep the <code class="docutils literal notranslate"><span class="pre">key</span></code> short and put more detail in <code class="docutils literal notranslate"><span class="pre">desc</span></code>.</p>
</div>
<div class="section" id="option-key-goto">
<h4>option-key ‘goto’<a class="headerlink" href="#option-key-goto" title="Permalink to this headline"></a></h4>
<p>This is the operational part of the option and fires only when the user chooses said option. Here
are three ways to write it</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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23</pre></div></td><td class="code"><div class="highlight"><pre><span></span>
<span class="k">def</span> <span class="nf">_action_two</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="c1"># do things ...</span>
<span class="k">return</span> <span class="s2">&quot;calculated_node_to_go_to&quot;</span>
<span class="k">def</span> <span class="nf">_action_three</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="c1"># do things ...</span>
<span class="k">return</span> <span class="s2">&quot;node_four&quot;</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;mode&quot;</span><span class="p">:</span> <span class="mi">4</span><span class="p">}</span>
<span class="k">def</span> <span class="nf">node_select</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="p">(</span><span class="s2">&quot;select one&quot;</span><span class="p">,</span>
<span class="s2">&quot;help - they all do different things ...&quot;</span><span class="p">)</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">({</span><span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Option one&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;node_one&quot;</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Option two&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="n">_action_two</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Option three&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="p">(</span><span class="n">_action_three</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span> <span class="s2">&quot;key2&quot;</span><span class="p">:</span> <span class="mi">2</span><span class="p">})}</span>
<span class="p">)</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>As seen above, <code class="docutils literal notranslate"><span class="pre">goto</span></code> could just be pointing to a single <code class="docutils literal notranslate"><span class="pre">nodename</span></code> string - the name of the node to
go to. When given like this, EvMenu will look for a node named like this and call its associated
function as</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1</pre></div></td><td class="code"><div class="highlight"><pre><span></span> <span class="n">nodename</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>Here, <code class="docutils literal notranslate"><span class="pre">raw_string</span></code> is always the input the user entered to make that choice and <code class="docutils literal notranslate"><span class="pre">kwargs</span></code> are the
same as those <code class="docutils literal notranslate"><span class="pre">kwargs</span></code> that already entered the <em>current</em> node (they are passed on).</p>
<p>Alternatively the <code class="docutils literal notranslate"><span class="pre">goto</span></code> could point to a “goto-callable”. Such callables are usually defined in the
same
module as the menu nodes and given names starting with <code class="docutils literal notranslate"><span class="pre">_</span></code> (to avoid being parsed as nodes
themselves). These callables will be called the same as a node function - <code class="docutils literal notranslate"><span class="pre">callable(caller,</span> <span class="pre">raw_string,</span> <span class="pre">**kwargs)</span></code>, where <code class="docutils literal notranslate"><span class="pre">raw_string</span></code> is what the user entered on this node and <code class="docutils literal notranslate"><span class="pre">**kwargs</span></code> is
forwarded from the node’s own input.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">goto</span></code> option key could also point to a tuple <code class="docutils literal notranslate"><span class="pre">(callable,</span> <span class="pre">kwargs)</span></code> - this allows for customizing
the kwargs passed into the goto-callable, for example you could use the same callable but change the
kwargs passed into it depending on which option was actually chosen.</p>
<p>The “goto callable” must either return a string <code class="docutils literal notranslate"><span class="pre">&quot;nodename&quot;</span></code> or a tuple <code class="docutils literal notranslate"><span class="pre">(&quot;nodename&quot;,</span> <span class="pre">mykwargs)</span></code>.
This will lead to the next node being called as either <code class="docutils literal notranslate"><span class="pre">nodename(caller,</span> <span class="pre">raw_string,</span> <span class="pre">**kwargs)</span></code> or
<code class="docutils literal notranslate"><span class="pre">nodename(caller,</span> <span class="pre">raw_string,</span> <span class="pre">**mykwargs)</span></code> - so this allows changing (or replacing) the options
going
into the next node depending on what option was chosen.</p>
<p>There is one important case - if the goto-callable returns <code class="docutils literal notranslate"><span class="pre">None</span></code> for a <code class="docutils literal notranslate"><span class="pre">nodename</span></code>, <em>the current
node will run again</em>, possibly with different kwargs. This makes it very easy to re-use a node over
and over, for example allowing different options to update some text form being passed and
manipulated for every iteration.</p>
<blockquote>
<div><p>The EvMenu also supports the <code class="docutils literal notranslate"><span class="pre">exec</span></code> option key. This allows for running a callable <em>before</em> the
goto-callable. This functionality comes from a time before goto could be a callable and is
<em>deprecated</em> as of Evennia 0.8. Use <code class="docutils literal notranslate"><span class="pre">goto</span></code> for all functionality where you’d before use <code class="docutils literal notranslate"><span class="pre">exec</span></code>.</p>
</div></blockquote>
</div>
</div>
</div>
<div class="section" id="temporary-storage">
<h2>Temporary storage<a class="headerlink" href="#temporary-storage" title="Permalink to this headline"></a></h2>
<p>When the menu starts, the EvMenu instance is stored on the caller as <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code>. Through
this object you can in principle reach the menu’s internal state if you know what you are doing.
This is also a good place to store temporary, more global variables that may be cumbersome to keep
passing from node to node via the <code class="docutils literal notranslate"><span class="pre">**kwargs</span></code>. The <code class="docutils literal notranslate"><span class="pre">_menutree</span></code> will be deleted automatically when the
menu closes, meaning you don’t need to worry about cleaning anything up.</p>
<p>If you want <em>permanent</em> state storage, it’s instead better to use an Attribute on <code class="docutils literal notranslate"><span class="pre">caller</span></code>. Remember
that this will remain after the menu closes though, so you need to handle any needed cleanup
yourself.</p>
</div>
<div class="section" id="customizing-menu-formatting">
<h2>Customizing Menu formatting<a class="headerlink" href="#customizing-menu-formatting" title="Permalink to this headline"></a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> display of nodes, options etc are controlled by a series of formatting methods on the
<code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> class. To customize these, simply create a new child class of <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> and override as
needed. Here is an example:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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45
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55</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">evennia.utils.evmenu</span> <span class="kn">import</span> <span class="n">EvMenu</span>
<span class="k">class</span> <span class="nc">MyEvMenu</span><span class="p">(</span><span class="n">EvMenu</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">nodetext_formatter</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">nodetext</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> Format the node text itself.</span>
<span class="sd"> Args:</span>
<span class="sd"> nodetext (str): The full node text (the text describing the node).</span>
<span class="sd"> Returns:</span>
<span class="sd"> nodetext (str): The formatted node text.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">def</span> <span class="nf">helptext_formatter</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">helptext</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> Format the node&#39;s help text</span>
<span class="sd"> Args:</span>
<span class="sd"> helptext (str): The unformatted help text for the node.</span>
<span class="sd"> Returns:</span>
<span class="sd"> helptext (str): The formatted help text.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">def</span> <span class="nf">options_formatter</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">optionlist</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> Formats the option block.</span>
<span class="sd"> Args:</span>
<span class="sd"> optionlist (list): List of (key, description) tuples for every</span>
<span class="sd"> option related to this node.</span>
<span class="sd"> caller (Object, Account or None, optional): The caller of the node.</span>
<span class="sd"> Returns:</span>
<span class="sd"> options (str): The formatted option display.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="k">def</span> <span class="nf">node_formatter</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">nodetext</span><span class="p">,</span> <span class="n">optionstext</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> Formats the entirety of the node.</span>
<span class="sd"> Args:</span>
<span class="sd"> nodetext (str): The node text as returned by `self.nodetext_formatter`.</span>
<span class="sd"> optionstext (str): The options display as returned by `self.options_formatter`.</span>
<span class="sd"> caller (Object, Account or None, optional): The caller of the node.</span>
<span class="sd"> Returns:</span>
<span class="sd"> node (str): The formatted node to display.</span>
<span class="sd"> &quot;&quot;&quot;</span>
</pre></div>
</td></tr></table></div>
<p>See <code class="docutils literal notranslate"><span class="pre">evennia/utils/evmenu.py</span></code> for the details of their default implementations.</p>
</div>
<div class="section" id="examples">
<h2>Examples:<a class="headerlink" href="#examples" title="Permalink to this headline"></a></h2>
<ul class="simple">
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-simple-branching-menu">Simple branching menu</a></strong> - choose from options</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-dynamic-goto">Dynamic goto</a></strong> - jumping to different nodes based on response</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-set-caller-properties">Set caller properties</a></strong> - a menu that changes things</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-get-arbitrary-input">Getting arbitrary input</a></strong> - entering text</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-storing-data-between-nodes">Storing data between nodes</a></strong> - keeping states and
information while in the menu</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-repeating-the-same-node">Repeating the same node</a></strong> - validating within the node
before moving to the next</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-full-menu">Full Menu</a>:</strong> a complete example</p></li>
<li><p><strong><a class="reference external" href="Components/EvMenu.html#example-yesno-prompt">Yes/No prompt</a></strong> - entering text with limited possible responses
(this is <em>not</em> using EvMenu but the conceptually similar yet technically unrelated <code class="docutils literal notranslate"><span class="pre">get_input</span></code>
helper function accessed as <code class="docutils literal notranslate"><span class="pre">evennia.utils.evmenu.get_input</span></code>).</p></li>
</ul>
<div class="section" id="example-simple-branching-menu">
<h3>Example: Simple branching menu<a class="headerlink" href="#example-simple-branching-menu" title="Permalink to this headline"></a></h3>
<p>Below is an example of a simple branching menu node leading to different other nodes depending on
choice:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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15</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="c1"># in mygame/world/mychargen.py</span>
<span class="k">def</span> <span class="nf">define_character</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> \
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> What aspect of your character do you want</span>
<span class="sd"> to change next?</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">({</span><span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Change the name&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;set_name&quot;</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;Change the description&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;set_description&quot;</span><span class="p">})</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="n">EvMenu</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="s2">&quot;world.mychargen&quot;</span><span class="p">,</span> <span class="n">startnode</span><span class="o">=</span><span class="s2">&quot;define_character&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>This will result in the following node display:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>What aspect of your character do you want
to change next?
_________________________
1: Change the name
2: Change the description
</pre></div>
</div>
<p>Note that since we didn’t specify the “name” key, EvMenu will let the user enter numbers instead. In
the following examples we will not include the <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> call but just show nodes running inside the
menu. Also, since <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> also takes a dictionary to describe the menu, we could have called it
like this instead in the example:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="n">EvMenu</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;define_character&quot;</span><span class="p">:</span> <span class="n">define_character</span><span class="p">},</span> <span class="n">startnode</span><span class="o">=</span><span class="s2">&quot;define_character&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
</div>
<div class="section" id="example-dynamic-goto">
<h3>Example: Dynamic goto<a class="headerlink" href="#example-dynamic-goto" title="Permalink to this headline"></a></h3>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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14</pre></div></td><td class="code"><div class="highlight"><pre><span></span>
<span class="k">def</span> <span class="nf">_is_in_mage_guild</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="k">if</span> <span class="n">caller</span><span class="o">.</span><span class="n">tags</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;mage&#39;</span><span class="p">,</span> <span class="n">category</span><span class="o">=</span><span class="s2">&quot;guild_member&quot;</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">&quot;mage_guild_welcome&quot;</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="s2">&quot;mage_guild_blocked&quot;</span>
<span class="k">def</span> <span class="nf">enter_guild</span><span class="p">:</span>
<span class="n">text</span> <span class="o">=</span> <span class="s1">&#39;You say to the mage guard:&#39;</span>
<span class="n">options</span> <span class="p">({</span><span class="s1">&#39;desc&#39;</span><span class="p">:</span> <span class="s1">&#39;I need to get in there.&#39;</span><span class="p">,</span>
<span class="s1">&#39;goto&#39;</span><span class="p">:</span> <span class="n">_is_in_mage_guild</span><span class="p">},</span>
<span class="p">{</span><span class="s1">&#39;desc&#39;</span><span class="p">:</span> <span class="s1">&#39;Never mind&#39;</span><span class="p">,</span>
<span class="s1">&#39;goto&#39;</span><span class="p">:</span> <span class="s1">&#39;end_conversation&#39;</span><span class="p">})</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>This simple callable goto will analyse what happens depending on who the <code class="docutils literal notranslate"><span class="pre">caller</span></code> is. The
<code class="docutils literal notranslate"><span class="pre">enter_guild</span></code> node will give you a choice of what to say to the guard. If you try to enter, you will
end up in different nodes depending on (in this example) if you have the right <a class="reference internal" href="Tags.html"><span class="doc">Tag</span></a> set on
yourself or not. Note that since we don’t include any ‘key’s in the option dictionary, you will just
get to pick between numbers.</p>
</div>
<div class="section" id="example-set-caller-properties">
<h3>Example: Set caller properties<a class="headerlink" href="#example-set-caller-properties" title="Permalink to this headline"></a></h3>
<p>Here is an example of passing arguments into the <code class="docutils literal notranslate"><span class="pre">goto</span></code> callable and use that to influence
which node it should go to next:</p>
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<span class="k">def</span> <span class="nf">_set_attribute</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="s2">&quot;Get which attribute to modify and set it&quot;</span>
<span class="n">attrname</span><span class="p">,</span> <span class="n">value</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s2">&quot;attr&quot;</span><span class="p">,</span> <span class="p">(</span><span class="bp">None</span><span class="p">,</span> <span class="bp">None</span><span class="p">))</span>
<span class="n">next_node</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s2">&quot;next_node&quot;</span><span class="p">)</span>
<span class="n">caller</span><span class="o">.</span><span class="n">attributes</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">attrname</span><span class="p">,</span> <span class="n">attrvalue</span><span class="p">)</span>
<span class="k">return</span> <span class="n">next_node</span>
<span class="k">def</span> <span class="nf">node_background</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> \
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> {} experienced a traumatic event</span>
<span class="sd"> in their childhood. What was it?</span>
<span class="sd"> &quot;&quot;&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">caller</span><span class="o">.</span><span class="n">key</span><span class="p">}</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">({</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;death&quot;</span><span class="p">,</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;A violent death in the family&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="p">(</span><span class="n">_set_attribute</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;attr&quot;</span><span class="p">:</span> <span class="p">(</span><span class="s2">&quot;experienced_violence&quot;</span><span class="p">,</span> <span class="bp">True</span><span class="p">),</span>
<span class="s2">&quot;next_node&quot;</span><span class="p">:</span> <span class="s2">&quot;node_violent_background&quot;</span><span class="p">})},</span>
<span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;betrayal&quot;</span><span class="p">,</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;The betrayal of a trusted grown-up&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="p">(</span><span class="n">_set_attribute</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;attr&quot;</span><span class="p">:</span> <span class="p">(</span><span class="s2">&quot;experienced_betrayal&quot;</span><span class="p">,</span> <span class="bp">True</span><span class="p">),</span>
<span class="s2">&quot;next_node&quot;</span><span class="p">:</span> <span class="s2">&quot;node_betrayal_background&quot;</span><span class="p">})})</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>This will give the following output:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>Kovash the magnificent experienced a traumatic event
in their childhood. What was it?
____________________________________________________
death: A violent death in the family
betrayal: The betrayal of a trusted grown-up
</pre></div>
</div>
<p>Note above how we use the <code class="docutils literal notranslate"><span class="pre">_set_attribute</span></code> helper function to set the attribute depending on the
User’s choice. In thie case the helper function doesn’t know anything about what node called it - we
even tell it which nodename it should return, so the choices leads to different paths in the menu.
We could also imagine the helper function analyzing what other choices</p>
</div>
<div class="section" id="example-get-arbitrary-input">
<h3>Example: Get arbitrary input<a class="headerlink" href="#example-get-arbitrary-input" title="Permalink to this headline"></a></h3>
<p>An example of the menu asking the user for input - any input.</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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<span class="k">def</span> <span class="nf">_set_name</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">inp</span> <span class="o">=</span> <span class="n">raw_string</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span>
<span class="n">prev_entry</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s2">&quot;prev_entry&quot;</span><span class="p">)</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">inp</span><span class="p">:</span>
<span class="c1"># a blank input either means OK or Abort</span>
<span class="k">if</span> <span class="n">prev_entry</span><span class="p">:</span>
<span class="n">caller</span><span class="o">.</span><span class="n">key</span> <span class="o">=</span> <span class="n">prev_entry</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;Set name to {}.&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">prev_entry</span><span class="p">))</span>
<span class="k">return</span> <span class="s2">&quot;node_background&quot;</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;Aborted.&quot;</span><span class="p">)</span>
<span class="k">return</span> <span class="s2">&quot;node_exit&quot;</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># re-run old node, but pass in the name given</span>
<span class="k">return</span> <span class="bp">None</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;prev_entry&quot;</span><span class="p">:</span> <span class="n">inp</span><span class="p">}</span>
<span class="k">def</span> <span class="nf">enter_name</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="c1"># check if we already entered a name before</span>
<span class="n">prev_entry</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s2">&quot;prev_entry&quot;</span><span class="p">)</span>
<span class="k">if</span> <span class="n">prev_entry</span><span class="p">:</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Current name: {}.</span><span class="se">\n</span><span class="s2">Enter another name or &lt;return&gt; to accept.&quot;</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Enter your character&#39;s name or &lt;return&gt; to abort.&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;_default&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="p">(</span><span class="n">_set_name</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;prev_entry&quot;</span><span class="p">:</span> <span class="n">prev_entry</span><span class="p">})}</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>This will display as</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Enter</span> <span class="n">your</span> <span class="n">character</span><span class="s1">&#39;s name or &lt;return&gt; to abort.</span>
<span class="o">&gt;</span> <span class="n">Gandalf</span>
<span class="n">Current</span> <span class="n">name</span><span class="p">:</span> <span class="n">Gandalf</span>
<span class="n">Enter</span> <span class="n">another</span> <span class="n">name</span> <span class="ow">or</span> <span class="o">&lt;</span><span class="k">return</span><span class="o">&gt;</span> <span class="n">to</span> <span class="n">accept</span><span class="o">.</span>
<span class="o">&gt;</span>
<span class="n">Set</span> <span class="n">name</span> <span class="n">to</span> <span class="n">Gandalf</span><span class="o">.</span>
</pre></div>
</div>
<p>Here we re-use the same node twice for reading the input data from the user. Whatever we enter will
be caught by the <code class="docutils literal notranslate"><span class="pre">_default</span></code> option and passed into the helper function. We also pass along whatever
name we have entered before. This allows us to react correctly on an “empty” input - continue to the
node named <code class="docutils literal notranslate"><span class="pre">&quot;node_background&quot;</span></code> if we accept the input or go to an exit node if we presses Return
without entering anything. By returning <code class="docutils literal notranslate"><span class="pre">None</span></code> from the helper function we automatically re-run the
previous node, but updating its ingoing kwargs to tell it to display a different text.</p>
</div>
<div class="section" id="example-storing-data-between-nodes">
<h3>Example: Storing data between nodes<a class="headerlink" href="#example-storing-data-between-nodes" title="Permalink to this headline"></a></h3>
<p>A convenient way to store data is to store it on the <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code> which you can reach from
every node. The advantage of doing this is that the <code class="docutils literal notranslate"><span class="pre">_menutree</span></code> NAttribute will be deleted
automatically when you exit the menu.</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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<span class="k">def</span> <span class="nf">_set_name</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">caller</span><span class="o">.</span><span class="n">ndb</span><span class="o">.</span><span class="n">_menutree</span><span class="o">.</span><span class="n">charactersheet</span> <span class="o">=</span> <span class="p">{}</span>
<span class="n">caller</span><span class="o">.</span><span class="n">ndb</span><span class="o">.</span><span class="n">_menutree</span><span class="o">.</span><span class="n">charactersheet</span><span class="p">[</span><span class="s1">&#39;name&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="n">raw_string</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;You set your name to {}&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">raw_string</span><span class="p">)</span>
<span class="k">return</span> <span class="s2">&quot;background&quot;</span>
<span class="k">def</span> <span class="nf">node_set_name</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s1">&#39;Enter your name:&#39;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;key&#39;</span><span class="p">:</span> <span class="s1">&#39;_default&#39;</span><span class="p">,</span>
<span class="s1">&#39;goto&#39;</span><span class="p">:</span> <span class="n">_set_name</span><span class="p">}</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="o">...</span>
<span class="k">def</span> <span class="nf">node_view_sheet</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Character sheet:</span><span class="se">\n</span><span class="s2"> {}&quot;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">ndb</span><span class="o">.</span><span class="n">_menutree</span><span class="o">.</span><span class="n">charactersheet</span><span class="p">)</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">({</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;Accept&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;finish_chargen&quot;</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;Decline&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;start_over&quot;</span><span class="p">})</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>Instead of passing the character sheet along from node to node through the <code class="docutils literal notranslate"><span class="pre">kwargs</span></code> we instead
set it up temporarily on <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree.charactersheet</span></code>. This makes it easy to reach from
all nodes. At the end we look at it and, if we accept the character the menu will likely save the
result to permanent storage and exit.</p>
<blockquote>
<div><p>One point to remember though is that storage on <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code> is not persistent across
<code class="docutils literal notranslate"><span class="pre">&#64;reloads</span></code>. If you are using a persistent menu (using <code class="docutils literal notranslate"><span class="pre">EvMenu(...,</span> <span class="pre">persistent=True)</span></code> you should
use
<code class="docutils literal notranslate"><span class="pre">caller.db</span></code> to store in-menu data like this as well. You must then yourself make sure to clean it
when the user exits the menu.</p>
</div></blockquote>
</div>
<div class="section" id="example-repeating-the-same-node">
<h3>Example: Repeating the same node<a class="headerlink" href="#example-repeating-the-same-node" title="Permalink to this headline"></a></h3>
<p>Sometimes you want to make a chain of menu nodes one after another, but you don’t want the user to
be able to continue to the next node until you have verified that what they input in the previous
node is ok. A common example is a login menu:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
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<span class="k">def</span> <span class="nf">_check_username</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="c1"># we assume lookup_username() exists</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">lookup_username</span><span class="p">(</span><span class="n">raw_string</span><span class="p">):</span>
<span class="c1"># re-run current node by returning `None`</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;|rUsername not found. Try again.&quot;</span><span class="p">)</span>
<span class="k">return</span> <span class="bp">None</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># username ok - continue to next node</span>
<span class="k">return</span> <span class="s2">&quot;node_password&quot;</span>
<span class="k">def</span> <span class="nf">node_username</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Please enter your user name.&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;_default&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="n">_check_username</span><span class="p">}</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="k">def</span> <span class="nf">_check_password</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">nattempts</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s2">&quot;nattempts&quot;</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="k">if</span> <span class="n">nattempts</span> <span class="o">&gt;</span> <span class="mi">3</span><span class="p">:</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;Too many failed attempts. Logging out&quot;</span><span class="p">)</span>
<span class="k">return</span> <span class="s2">&quot;node_abort&quot;</span>
<span class="k">elif</span> <span class="ow">not</span> <span class="n">validate_password</span><span class="p">(</span><span class="n">raw_string</span><span class="p">):</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;Password error. Try again.&quot;</span><span class="p">)</span>
<span class="k">return</span> <span class="bp">None</span><span class="p">,</span> <span class="p">{</span><span class="s2">&quot;nattempts&quot;</span><span class="p">,</span> <span class="n">nattempts</span> <span class="o">+</span> <span class="mi">1</span><span class="p">}</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># password accepted</span>
<span class="k">return</span> <span class="s2">&quot;node_login&quot;</span>
<span class="k">def</span> <span class="nf">node_password</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="n">text</span> <span class="o">=</span> <span class="s2">&quot;Enter your password.&quot;</span>
<span class="n">options</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;_default&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="n">_check_password</span><span class="p">}</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>This will display something like</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">---------------------------</span>
<span class="n">Please</span> <span class="n">enter</span> <span class="n">your</span> <span class="n">username</span><span class="o">.</span>
<span class="o">---------------------------</span>
<span class="o">&gt;</span> <span class="n">Fo</span>
<span class="o">------------------------------</span>
<span class="n">Username</span> <span class="ow">not</span> <span class="n">found</span><span class="o">.</span> <span class="n">Try</span> <span class="n">again</span><span class="o">.</span>
<span class="n">______________________________</span>
<span class="n">abort</span><span class="p">:</span> <span class="p">(</span><span class="n">back</span> <span class="n">to</span> <span class="n">start</span><span class="p">)</span>
<span class="o">------------------------------</span>
<span class="o">&gt;</span> <span class="n">Foo</span>
<span class="o">---------------------------</span>
<span class="n">Please</span> <span class="n">enter</span> <span class="n">your</span> <span class="n">password</span><span class="o">.</span>
<span class="o">---------------------------</span>
<span class="o">&gt;</span> <span class="n">Bar</span>
<span class="o">--------------------------</span>
<span class="n">Password</span> <span class="n">error</span><span class="o">.</span> <span class="n">Try</span> <span class="n">again</span><span class="o">.</span>
<span class="o">--------------------------</span>
</pre></div>
</div>
<p>And so on.</p>
<p>Here the goto-callables will return to the previous node if there is an error. In the case of
password attempts, this will tick up the <code class="docutils literal notranslate"><span class="pre">nattempts</span></code> argument that will get passed on from iteration
to iteration until too many attempts have been made.</p>
</div>
<div class="section" id="defining-nodes-in-a-dictionary">
<h3>Defining nodes in a dictionary<a class="headerlink" href="#defining-nodes-in-a-dictionary" title="Permalink to this headline"></a></h3>
<p>You can also define your nodes directly in a dictionary to feed into the <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> creator.</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">mynode</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="c1"># a normal menu node function</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
<span class="n">menu_data</span> <span class="o">=</span> <span class="p">{</span><span class="s2">&quot;node1&quot;</span><span class="p">:</span> <span class="n">mynode</span><span class="p">,</span>
<span class="s2">&quot;node2&quot;</span><span class="p">:</span> <span class="k">lambda</span> <span class="n">caller</span><span class="p">:</span> <span class="p">(</span>
<span class="s2">&quot;This is the node text&quot;</span><span class="p">,</span>
<span class="p">({</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;lambda node 1&quot;</span><span class="p">,</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;go to node 1 (mynode)&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;node1&quot;</span><span class="p">},</span>
<span class="p">{</span><span class="s2">&quot;key&quot;</span><span class="p">:</span> <span class="s2">&quot;lambda node 2&quot;</span><span class="p">,</span>
<span class="s2">&quot;desc&quot;</span><span class="p">:</span> <span class="s2">&quot;go to thirdnode&quot;</span><span class="p">,</span>
<span class="s2">&quot;goto&quot;</span><span class="p">:</span> <span class="s2">&quot;node3&quot;</span><span class="p">})),</span>
<span class="s2">&quot;node3&quot;</span><span class="p">:</span> <span class="k">lambda</span> <span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">:</span> <span class="p">(</span>
<span class="c1"># ... etc ) }</span>
<span class="c1"># start menu, assuming &#39;caller&#39; is available from earlier</span>
<span class="n">EvMenu</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">menu_data</span><span class="p">,</span> <span class="n">startnode</span><span class="o">=</span><span class="s2">&quot;node1&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>The keys of the dictionary become the node identifiers. You can use any callable on the right form
to describe each node. If you use Python <code class="docutils literal notranslate"><span class="pre">lambda</span></code> expressions you can make nodes really on the fly.
If you do, the lambda expression must accept one or two arguments and always return a tuple with two
elements (the text of the node and its options), same as any menu node function.</p>
<p>Creating menus like this is one way to present a menu that changes with the circumstances - you
could for example remove or add nodes before launching the menu depending on some criteria. The
drawback is that a <code class="docutils literal notranslate"><span class="pre">lambda</span></code> expression <a class="reference external" href="https://docs.python.org/2/tutorial/controlflow.html#lambda-expressions">is much more
limited</a> than a full
function - for example you can’t use other Python keywords like <code class="docutils literal notranslate"><span class="pre">if</span></code> inside the body of the
<code class="docutils literal notranslate"><span class="pre">lambda</span></code>.</p>
<p>Unless you are dealing with a relatively simple dynamic menu, defining menus with lambda’s is
probably more work than it’s worth: You can create dynamic menus by instead making each node
function more clever. See the <a class="reference internal" href="../Howto/NPC-shop-Tutorial.html"><span class="doc">NPC shop tutorial</span></a> for an example of this.</p>
</div>
</div>
<div class="section" id="ask-for-simple-input">
<h2>Ask for simple input<a class="headerlink" href="#ask-for-simple-input" title="Permalink to this headline"></a></h2>
<p>This describes two ways for asking for simple questions from the user. Using Python’s <code class="docutils literal notranslate"><span class="pre">input</span></code>
will <em>not</em> work in Evennia. <code class="docutils literal notranslate"><span class="pre">input</span></code> will <em>block</em> the entire server for <em>everyone</em> until that one
player has entered their text, which is not what you want.</p>
<div class="section" id="the-yield-way">
<h3>The <code class="docutils literal notranslate"><span class="pre">yield</span></code> way<a class="headerlink" href="#the-yield-way" title="Permalink to this headline"></a></h3>
<p>In the <code class="docutils literal notranslate"><span class="pre">func</span></code> method of your Commands (only) you can use Python’s built-in <code class="docutils literal notranslate"><span class="pre">yield</span></code> command to
request input in a similar way to <code class="docutils literal notranslate"><span class="pre">input</span></code>. It looks like this:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="n">result</span> <span class="o">=</span> <span class="k">yield</span><span class="p">(</span><span class="s2">&quot;Please enter your answer:&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>This will send “Please enter your answer” to the Command’s <code class="docutils literal notranslate"><span class="pre">self.caller</span></code> and then pause at that
point. All other players at the server will be unaffected. Once caller enteres a reply, the code
execution will continue and you can do stuff with the <code class="docutils literal notranslate"><span class="pre">result</span></code>. Here is an example:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1
2
3
4
5
6
7
8</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">evennia</span> <span class="kn">import</span> <span class="n">Command</span>
<span class="k">class</span> <span class="nc">CmdTestInput</span><span class="p">(</span><span class="n">Command</span><span class="p">):</span>
<span class="n">key</span> <span class="o">=</span> <span class="s2">&quot;test&quot;</span>
<span class="k">def</span> <span class="nf">func</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">result</span> <span class="o">=</span> <span class="k">yield</span><span class="p">(</span><span class="s2">&quot;Please enter something:&quot;</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="n">f</span><span class="s2">&quot;You entered {result}.&quot;</span><span class="p">)</span>
<span class="n">result2</span> <span class="o">=</span> <span class="k">yield</span><span class="p">(</span><span class="s2">&quot;Now enter something else:&quot;</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="n">f</span><span class="s2">&quot;You now entered {result2}.&quot;</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>Using <code class="docutils literal notranslate"><span class="pre">yield</span></code> is simple and intuitive, but it will only access input from <code class="docutils literal notranslate"><span class="pre">self.caller</span></code> and you
cannot abort or time out the pause until the player has responded. Under the hood, it is actually
just a wrapper calling <code class="docutils literal notranslate"><span class="pre">get_input</span></code> described in the following section.</p>
<blockquote>
<div><p>Important Note: In Python you <em>cannot mix <code class="docutils literal notranslate"><span class="pre">yield</span></code> and <code class="docutils literal notranslate"><span class="pre">return</span> <span class="pre">&lt;value&gt;</span></code> in the same method</em>. It has
to do with <code class="docutils literal notranslate"><span class="pre">yield</span></code> turning the method into a
<a class="reference external" href="https://www.learnpython.org/en/Generators">generator</a>. A <code class="docutils literal notranslate"><span class="pre">return</span></code> without an argument works, you
can just not do <code class="docutils literal notranslate"><span class="pre">return</span> <span class="pre">&lt;value&gt;</span></code>. This is usually not something you need to do in <code class="docutils literal notranslate"><span class="pre">func()</span></code> anyway,
but worth keeping in mind.</p>
</div></blockquote>
</div>
<div class="section" id="the-get-input-way">
<h3>The <code class="docutils literal notranslate"><span class="pre">get_input</span></code> way<a class="headerlink" href="#the-get-input-way" title="Permalink to this headline"></a></h3>
<p>The evmenu module offers a helper function named <code class="docutils literal notranslate"><span class="pre">get_input</span></code>. This is wrapped by the <code class="docutils literal notranslate"><span class="pre">yield</span></code>
statement which is often easier and more intuitive to use. But <code class="docutils literal notranslate"><span class="pre">get_input</span></code> offers more flexibility
and power if you need it. While in the same module as <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code>, <code class="docutils literal notranslate"><span class="pre">get_input</span></code> is technically unrelated
to it. The <code class="docutils literal notranslate"><span class="pre">get_input</span></code> allows you to ask and receive simple one-line input from the user without
launching the full power of a menu to do so. To use, call <code class="docutils literal notranslate"><span class="pre">get_input</span></code> like this:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="n">get_input</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">prompt</span><span class="p">,</span> <span class="n">callback</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>Here <code class="docutils literal notranslate"><span class="pre">caller</span></code> is the entity that should receive the prompt for input given as <code class="docutils literal notranslate"><span class="pre">prompt</span></code>. The
<code class="docutils literal notranslate"><span class="pre">callback</span></code> is a callable <code class="docutils literal notranslate"><span class="pre">function(caller,</span> <span class="pre">prompt,</span> <span class="pre">user_input)</span></code> that you define to handle the answer
from the user. When run, the caller will see <code class="docutils literal notranslate"><span class="pre">prompt</span></code> appear on their screens and <em>any</em> text they
enter will be sent into the callback for whatever processing you want.</p>
<p>Below is a fully explained callback and example call:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">evennia</span> <span class="kn">import</span> <span class="n">Command</span>
<span class="kn">from</span> <span class="nn">evennia.utils.evmenu</span> <span class="kn">import</span> <span class="n">get_input</span>
<span class="k">def</span> <span class="nf">callback</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">prompt</span><span class="p">,</span> <span class="n">user_input</span><span class="p">):</span>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd"> This is a callback you define yourself.</span>
<span class="sd"> Args:</span>
<span class="sd"> caller (Account or Object): The one being asked</span>
<span class="sd"> for input</span>
<span class="sd"> prompt (str): A copy of the current prompt</span>
<span class="sd"> user_input (str): The input from the account.</span>
<span class="sd"> Returns:</span>
<span class="sd"> repeat (bool): If not set or False, exit the</span>
<span class="sd"> input prompt and clean up. If returning anything</span>
<span class="sd"> True, stay in the prompt, which means this callback</span>
<span class="sd"> will be called again with the next user input.</span>
<span class="sd"> &quot;&quot;&quot;</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="n">f</span><span class="s2">&quot;When asked &#39;{prompt}&#39;, you answered &#39;{user_input}&#39;.&quot;</span><span class="p">)</span>
<span class="n">get_input</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="s2">&quot;Write something! &quot;</span><span class="p">,</span> <span class="n">callback</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
<p>This will show as</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>Write something!
&gt; Hello
When asked &#39;Write something!&#39;, you answered &#39;Hello&#39;.
</pre></div>
</div>
<p>Normally, the <code class="docutils literal notranslate"><span class="pre">get_input</span></code> function quits after any input, but as seen in the example docs, you could
return True from the callback to repeat the prompt until you pass whatever check you want.</p>
<blockquote>
<div><p>Note: You <em>cannot</em> link consecutive questions by putting a new <code class="docutils literal notranslate"><span class="pre">get_input</span></code> call inside the
callback If you want that you should use an EvMenu instead (see the <a class="reference external" href="Components/EvMenu.html#example-repeating-the-same-node">Repeating the same
node</a> example above). Otherwise you can either peek at the
implementation of <code class="docutils literal notranslate"><span class="pre">get_input</span></code> and implement your own mechanism (it’s just using cmdset nesting) or
you can look at <a class="reference external" href="https://groups.google.com/forum/#%21category-topic/evennia/evennia-questions/16pi0SfMO5U">this extension suggested on the mailing
list</a>.</p>
</div></blockquote>
<div class="section" id="example-yes-no-prompt">
<h4>Example: Yes/No prompt<a class="headerlink" href="#example-yes-no-prompt" title="Permalink to this headline"></a></h4>
<p>Below is an example of a Yes/No prompt using the <code class="docutils literal notranslate"><span class="pre">get_input</span></code> function:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11
12
13
14</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">yesno</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">prompt</span><span class="p">,</span> <span class="n">result</span><span class="p">):</span>
<span class="k">if</span> <span class="n">result</span><span class="o">.</span><span class="n">lower</span><span class="p">()</span> <span class="ow">in</span> <span class="p">(</span><span class="s2">&quot;y&quot;</span><span class="p">,</span> <span class="s2">&quot;yes&quot;</span><span class="p">,</span> <span class="s2">&quot;n&quot;</span><span class="p">,</span> <span class="s2">&quot;no&quot;</span><span class="p">):</span>
<span class="c1"># do stuff to handle the yes/no answer</span>
<span class="c1"># ...</span>
<span class="c1"># if we return None/False the prompt state</span>
<span class="c1"># will quit after this</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># the answer is not on the right yes/no form</span>
<span class="n">caller</span><span class="o">.</span><span class="n">msg</span><span class="p">(</span><span class="s2">&quot;Please answer Yes or No. </span><span class="se">\n</span><span class="s2">{prompt}&quot;</span><span class="p">)</span>
<span class="err">@</span> <span class="c1"># returning True will make sure the prompt state is not exited</span>
<span class="k">return</span> <span class="bp">True</span>
<span class="c1"># ask the question</span>
<span class="n">get_input</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="s2">&quot;Is Evennia great (Yes/No)?&quot;</span><span class="p">,</span> <span class="n">yesno</span><span class="p">)</span>
</pre></div>
</td></tr></table></div>
</div>
</div>
</div>
<div class="section" id="the-list-node-decorator">
<h2>The <code class="docutils literal notranslate"><span class="pre">&#64;list_node</span></code> decorator<a class="headerlink" href="#the-list-node-decorator" title="Permalink to this headline"></a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">evennia.utils.evmenu.list_node</span></code> is an advanced decorator for use with <code class="docutils literal notranslate"><span class="pre">EvMenu</span></code> node functions.
It is used to quickly create menus for manipulating large numbers of items.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">text</span> <span class="n">here</span>
<span class="n">______________________________________________</span>
<span class="mf">1.</span> <span class="n">option1</span> <span class="mf">7.</span> <span class="n">option7</span> <span class="mf">13.</span> <span class="n">option13</span>
<span class="mf">2.</span> <span class="n">option2</span> <span class="mf">8.</span> <span class="n">option8</span> <span class="mf">14.</span> <span class="n">option14</span>
<span class="mf">3.</span> <span class="n">option3</span> <span class="mf">9.</span> <span class="n">option9</span> <span class="p">[</span><span class="n">p</span><span class="p">]</span><span class="n">revius</span> <span class="n">page</span>
<span class="mf">4.</span> <span class="n">option4</span> <span class="mf">10.</span> <span class="n">option10</span> <span class="n">page</span> <span class="mi">2</span>
<span class="mf">5.</span> <span class="n">option5</span> <span class="mf">11.</span> <span class="n">option11</span> <span class="p">[</span><span class="n">n</span><span class="p">]</span><span class="n">ext</span> <span class="n">page</span>
<span class="mf">6.</span> <span class="n">option6</span> <span class="mf">12.</span> <span class="n">option12</span>
</pre></div>
</div>
<p>The menu will automatically create an multi-page option listing that one can flip through. One can
inpect each entry and then select them with prev/next. This is how it is used:</p>
<div class="highlight-python notranslate"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre> 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17</pre></div></td><td class="code"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">evennia.utils.evmenu</span> <span class="kn">import</span> <span class="n">list_node</span>
<span class="o">...</span>
<span class="n">_options</span><span class="p">(</span><span class="n">caller</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="s1">&#39;option1&#39;</span><span class="p">,</span> <span class="s1">&#39;option2&#39;</span><span class="p">,</span> <span class="o">...</span> <span class="s1">&#39;option100&#39;</span><span class="p">]</span>
<span class="n">_select</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">menuchoice</span><span class="p">,</span> <span class="n">available_choices</span><span class="p">):</span>
<span class="c1"># analyze choice</span>
<span class="k">return</span> <span class="s2">&quot;next_node&quot;</span>
<span class="nd">@list_node</span><span class="p">(</span><span class="n">options</span><span class="p">,</span> <span class="n">select</span><span class="o">=</span><span class="n">_select</span><span class="p">,</span> <span class="n">pagesize</span><span class="o">=</span><span class="mi">10</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">node_mylist</span><span class="p">(</span><span class="n">caller</span><span class="p">,</span> <span class="n">raw_string</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="o">...</span>
<span class="k">return</span> <span class="n">text</span><span class="p">,</span> <span class="n">options</span>
</pre></div>
</td></tr></table></div>
<p>The <code class="docutils literal notranslate"><span class="pre">options</span></code> argument to <code class="docutils literal notranslate"><span class="pre">list_node</span></code> is either a list, a generator or a callable returning a list
of strings for each option that should be displayed in the node.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">select</span></code> is a callable in the example above but could also be the name of a menu node. If a
callable, the <code class="docutils literal notranslate"><span class="pre">menuchoice</span></code> argument holds the selection done and <code class="docutils literal notranslate"><span class="pre">available_choices</span></code> holds all the
options available. The callable should return the menu to go to depending on the selection (or
<code class="docutils literal notranslate"><span class="pre">None</span></code> to rerun the same node). If the name of a menu node, the selection will be passed as
<code class="docutils literal notranslate"><span class="pre">selection</span></code> kwarg to that node.</p>
<p>The decorated node itself should return <code class="docutils literal notranslate"><span class="pre">text</span></code> to display in the node. It must return at least an
empty dictionary for its options. It returning options, those will supplement the options
auto-created by the <code class="docutils literal notranslate"><span class="pre">list_node</span></code> decorator.</p>
</div>
<div class="section" id="assorted-notes">
<h2>Assorted notes<a class="headerlink" href="#assorted-notes" title="Permalink to this headline"></a></h2>
<p>The EvMenu is implemented using <a class="reference internal" href="Commands.html"><span class="doc">Commands</span></a>. When you start a new EvMenu, the user of the
menu will be assigned a <a class="reference internal" href="Command-Sets.html"><span class="doc">CmdSet</span></a> with the commands they need to navigate the menu.
This means that if you were to, from inside the menu, assign a new command set to the caller, <em>you
may override the Menu Cmdset and kill the menu</em>. If you want to assign cmdsets to the caller as part
of the menu, you should store the cmdset on <code class="docutils literal notranslate"><span class="pre">caller.ndb._menutree</span></code> and wait to actually assign it
until the exit node.</p>
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<p><h3><a href="../index.html">Table of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">EvMenu</a><ul>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#launching-the-menu">Launching the menu</a></li>
<li><a class="reference internal" href="#the-menu-nodes">The Menu nodes</a><ul>
<li><a class="reference internal" href="#input-arguments-to-the-node">Input arguments to the node</a></li>
<li><a class="reference internal" href="#return-values-from-the-node">Return values from the node</a><ul>
<li><a class="reference internal" href="#text">text</a></li>
<li><a class="reference internal" href="#options">options</a><ul>
<li><a class="reference internal" href="#option-key-key">option-key ‘key’</a></li>
</ul>
</li>
<li><a class="reference internal" href="#option-key-desc">option-key ‘desc’</a></li>
<li><a class="reference internal" href="#option-key-goto">option-key ‘goto’</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#temporary-storage">Temporary storage</a></li>
<li><a class="reference internal" href="#customizing-menu-formatting">Customizing Menu formatting</a></li>
<li><a class="reference internal" href="#examples">Examples:</a><ul>
<li><a class="reference internal" href="#example-simple-branching-menu">Example: Simple branching menu</a></li>
<li><a class="reference internal" href="#example-dynamic-goto">Example: Dynamic goto</a></li>
<li><a class="reference internal" href="#example-set-caller-properties">Example: Set caller properties</a></li>
<li><a class="reference internal" href="#example-get-arbitrary-input">Example: Get arbitrary input</a></li>
<li><a class="reference internal" href="#example-storing-data-between-nodes">Example: Storing data between nodes</a></li>
<li><a class="reference internal" href="#example-repeating-the-same-node">Example: Repeating the same node</a></li>
<li><a class="reference internal" href="#defining-nodes-in-a-dictionary">Defining nodes in a dictionary</a></li>
</ul>
</li>
<li><a class="reference internal" href="#ask-for-simple-input">Ask for simple input</a><ul>
<li><a class="reference internal" href="#the-yield-way">The <code class="docutils literal notranslate"><span class="pre">yield</span></code> way</a></li>
<li><a class="reference internal" href="#the-get-input-way">The <code class="docutils literal notranslate"><span class="pre">get_input</span></code> way</a><ul>
<li><a class="reference internal" href="#example-yes-no-prompt">Example: Yes/No prompt</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#the-list-node-decorator">The <code class="docutils literal notranslate"><span class="pre">&#64;list_node</span></code> decorator</a></li>
<li><a class="reference internal" href="#assorted-notes">Assorted notes</a></li>
</ul>
</li>
</ul>
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<h3>Versions</h3>
<ul>
<li><a href="EvMenu.html">1.0-dev (develop branch)</a></li>
<li><a href="../../0.9.5/index.html">0.9.5 (v0.9.5 branch)</a></li>
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