spend most time working with. Objects are <aclass="reference internal"href="Typeclasses.html"><spanclass="doc std std-doc">Typeclassed</span></a> entities.</p>
<p>An Evennia Object is, by definition, a Python class that includes
<aclass="reference internal"href="../api/evennia.objects.objects.html#evennia.objects.objects.DefaultObject"title="evennia.objects.objects.DefaultObject"><spanclass="xref myst py py-class">evennia.objects.objects.DefaultObject</span></a> among its
parents. Evennia defines several subclasses of <codeclass="docutils literal notranslate"><spanclass="pre">DefaultObject</span></code>:</p>
the normal in-game Character, controlled by a player.</p></li>
<li><p><aclass="reference internal"href="../api/evennia.objects.objects.html#evennia.objects.objects.DefaultRoom"title="evennia.objects.objects.DefaultRoom"><spanclass="xref myst py py-class">evennia.objects.objects.DefaultRoom</span></a> - a location in the game world.</p></li>
<li><p><aclass="reference internal"href="../api/evennia.objects.objects.html#evennia.objects.objects.DefaultExit"title="evennia.objects.objects.DefaultExit"><spanclass="xref myst py py-class">evennia.objects.objects.DefaultExit</span></a> - an entity that (usually) sits
in a room and represents a one-way connection to another location.</p></li>
</ul>
<p>You will usually not use the <codeclass="docutils literal notranslate"><spanclass="pre">Default*</span></code> parents themselves. In <codeclass="docutils literal notranslate"><spanclass="pre">mygame/typeclasses/</span></code> there are
convenient subclasses to use. They are empty, and thus identical to
the defaults. Tweaking them is one of the main ways to customize you game!</p>
<ulclass="simple">
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">mygame.typeclasses.objects.Object</span></code> (inherits from <codeclass="docutils literal notranslate"><spanclass="pre">DefaultObject</span></code>)</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">mygame.typeclasses.characters.Character</span></code> (inherits from <codeclass="docutils literal notranslate"><spanclass="pre">DefaultCharacter</span></code>)</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">mygame.typeclasses.rooms.Room</span></code> (inherits from <codeclass="docutils literal notranslate"><spanclass="pre">DefaultRoom</span></code>)</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">mygame.typeclasses.exits.Exit</span></code> (inherits from <codeclass="docutils literal notranslate"><spanclass="pre">DefaultExit</span></code>)</p></li>
<spanclass="s2">"this is called only once, when object is first created"</span>
<spanclass="c1"># add a persistent attribute 'desc'</span>
<spanclass="c1"># to object (silly example).</span>
<spanclass="bp">self</span><spanclass="o">.</span><spanclass="n">db</span><spanclass="o">.</span><spanclass="n">desc</span><spanclass="o">=</span><spanclass="s2">"This is a pretty rose with thorns."</span>
<p>Now you just need to point to the class <em>Rose</em> with the <codeclass="docutils literal notranslate"><spanclass="pre">create</span></code> command
<p>What the <codeclass="docutils literal notranslate"><spanclass="pre">create</span></code> command actually <em>does</em> is to use the <aclass="reference internal"href="../api/evennia.utils.create.html#evennia.utils.create.create_object"title="evennia.utils.create.create_object"><spanclass="xref myst py py-func">evennia.create_object</span></a>
function. You can do the same thing yourself in code:</p>
<p>(The <codeclass="docutils literal notranslate"><spanclass="pre">create</span></code> command will auto-append the most likely path to your typeclass, if you enter the
call manually you have to give the full path to the class. The <codeclass="docutils literal notranslate"><spanclass="pre">create.create_object</span></code> function is
powerful and should be used for all coded object creating (so this is what you use when defining
<p>This particular Rose class doesn’t really do much, all it does it make sure the attribute
<codeclass="docutils literal notranslate"><spanclass="pre">desc</span></code>(which is what the <codeclass="docutils literal notranslate"><spanclass="pre">look</span></code> command looks for) is pre-set, which is pretty pointless since you
will usually want to change this at build time (using the <codeclass="docutils literal notranslate"><spanclass="pre">desc</span></code> command or using the
<h2>Adding common functionality<aclass="headerlink"href="#adding-common-functionality"title="Permalink to this headline">¶</a></h2>
<p><codeclass="docutils literal notranslate"><spanclass="pre">Object</span></code>, <codeclass="docutils literal notranslate"><spanclass="pre">Character</span></code>, <codeclass="docutils literal notranslate"><spanclass="pre">Room</span></code> and <codeclass="docutils literal notranslate"><spanclass="pre">Exit</span></code> also inherit from <codeclass="docutils literal notranslate"><spanclass="pre">mygame.typeclasses.objects.ObjectParent</span></code>.
This is an empty ‘mixin’ class. Optionally, you can modify this class if you want to easily add some <em>common</em> functionality to all
your Objects, Characters, Rooms and Exits at once. You can still customize each subclass separately (see the Python
docs on <aclass="reference external"href="https://docs.python.org/3/tutorial/classes.html#multiple-inheritance">multiple inheritance</a> for details).</p>
<p>For example:</p>
<divclass="highlight-python notranslate"><divclass="highlight"><pre><span></span><spanclass="c1"># in mygame/typeclasses/objects.py</span>
<p>Beyond the properties assigned to all <aclass="reference internal"href="Typeclasses.html"><spanclass="doc std std-doc">typeclassed</span></a> objects (see that page for a list
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">aliases</span></code> - a handler that allows you to add and remove aliases from this object. Use
<codeclass="docutils literal notranslate"><spanclass="pre">aliases.add()</span></code> to add a new alias and <codeclass="docutils literal notranslate"><spanclass="pre">aliases.remove()</span></code> to remove one.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">location</span></code> - a reference to the object currently containing this object.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">home</span></code> is a backup location. The main motivation is to have a safe place to move the object to if
its <codeclass="docutils literal notranslate"><spanclass="pre">location</span></code> is destroyed. All objects should usually have a home location for safety.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">destination</span></code> - this holds a reference to another object this object links to in some way. Its
main use is for <aclass="reference internal"href="#exits"><spanclass="std std-doc">Exits</span></a>, it’s otherwise usually unset.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">nicks</span></code> - as opposed to aliases, a <aclass="reference internal"href="Nicks.html"><spanclass="doc std std-doc">Nick</span></a> holds a convenient nickname replacement for a
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">account</span></code> - this holds a reference to a connected <aclass="reference internal"href="Accounts.html"><spanclass="doc std std-doc">Account</span></a> controlling this object (if
any). Note that this is set also if the controlling account is <em>not</em> currently online - to test if
an account is online, use the <codeclass="docutils literal notranslate"><spanclass="pre">has_account</span></code> property instead.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">sessions</span></code> - if <codeclass="docutils literal notranslate"><spanclass="pre">account</span></code> field is set <em>and the account is online</em>, this is a list of all active
sessions (server connections) to contact them through (it may be more than one if multiple
connections are allowed in settings).</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">has_account</span></code> - a shorthand for checking if an <em>online</em> account is currently connected to this
object.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">contents</span></code> - this returns a list referencing all objects ‘inside’ this object (i,e. which has this
object set as their <codeclass="docutils literal notranslate"><spanclass="pre">location</span></code>).</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">exits</span></code> - this returns all objects inside this object that are <em>Exits</em>, that is, has the
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">cmdset</span></code> - this is a handler that stores all <aclass="reference internal"href="Command-Sets.html"><spanclass="doc std std-doc">command sets</span></a> defined on the
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">scripts</span></code> - this is a handler that manages <aclass="reference internal"href="Scripts.html"><spanclass="doc std std-doc">Scripts</span></a> attached to the object (if any).</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">msg()</span></code> - this function is used to send messages from the server to an account connected to this
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">msg_contents()</span></code> - calls <codeclass="docutils literal notranslate"><spanclass="pre">msg</span></code> on all objects inside this object.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">search()</span></code> - this is a convenient shorthand to search for a specific object, at a given location
or globally. It’s mainly useful when defining commands (in which case the object executing the
command is named <codeclass="docutils literal notranslate"><spanclass="pre">caller</span></code> and one can do <codeclass="docutils literal notranslate"><spanclass="pre">caller.search()</span></code> to find objects in the room to operate
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">execute_cmd()</span></code> - Lets the object execute the given string as if it was given on the command line.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">move_to</span></code> - perform a full move of this object to a new location. This is the main move method
and will call all relevant hooks, do all checks etc.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">clear_exits()</span></code> - will delete all <aclass="reference internal"href="#exits"><spanclass="std std-doc">Exits</span></a> to <em>and</em> from this object.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">clear_contents()</span></code> - this will not delete anything, but rather move all contents (except Exits) to
their designated <codeclass="docutils literal notranslate"><spanclass="pre">Home</span></code> locations.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">delete()</span></code> - deletes this object, first calling <codeclass="docutils literal notranslate"><spanclass="pre">clear_exits()</span></code> and
<p>The Object Typeclass defines many more <em>hook methods</em> beyond <codeclass="docutils literal notranslate"><spanclass="pre">at_object_creation</span></code>. Evennia calls
these hooks at various points. When implementing your custom objects, you will inherit from the
base parent and overload these hooks with your own custom code. See <codeclass="docutils literal notranslate"><spanclass="pre">evennia.objects.objects</span></code> for an
updated list of all the available hooks or the <aclass="reference internal"href="../api/evennia.objects.objects.html#evennia.objects.objects.DefaultObject"title="evennia.objects.objects.DefaultObject"><spanclass="xref myst py py-class">API for DefaultObject here</span></a>.</p>
<h2>Subclasses of <codeclass="docutils literal notranslate"><spanclass="pre">Object</span></code><aclass="headerlink"href="#subclasses-of-object"title="Permalink to this headline">¶</a></h2>
<p>Characters are objects controlled by <aclass="reference internal"href="Accounts.html"><spanclass="doc std std-doc">Accounts</span></a>. When a new Account
logs in to Evennia for the first time, a new <codeclass="docutils literal notranslate"><spanclass="pre">Character</span></code> object is created and
the Account object is assigned to the <codeclass="docutils literal notranslate"><spanclass="pre">account</span></code> attribute. A <codeclass="docutils literal notranslate"><spanclass="pre">Character</span></code> object
creation, or the account will not be able to issue any commands! If you just
inherit your own class from <codeclass="docutils literal notranslate"><spanclass="pre">evennia.DefaultCharacter</span></code> and make sure to use
<codeclass="docutils literal notranslate"><spanclass="pre">super()</span></code> to call the parent methods you should be fine. In
<codeclass="docutils literal notranslate"><spanclass="pre">mygame/typeclasses/characters.py</span></code> is an empty <codeclass="docutils literal notranslate"><spanclass="pre">Character</span></code> class ready for you
<p><em>Rooms</em> are the root containers of all other objects. The only thing really separating a room from
any other object is that they have no <codeclass="docutils literal notranslate"><spanclass="pre">location</span></code> of their own and that default commands like <codeclass="docutils literal notranslate"><spanclass="pre">@dig</span></code>
creates objects of this class - so if you want to expand your rooms with more functionality, just
inherit from <codeclass="docutils literal notranslate"><spanclass="pre">ev.DefaultRoom</span></code>. In <codeclass="docutils literal notranslate"><spanclass="pre">mygame/typeclasses/rooms.py</span></code> is an empty <codeclass="docutils literal notranslate"><spanclass="pre">Room</span></code> class ready for
define a special <aclass="reference internal"href="Commands.html"><spanclass="doc std std-doc">Transit Command</span></a> on themselves when they are created. This command is
doing). Exits are <aclass="reference internal"href="Locks.html"><spanclass="doc std std-doc">locked</span></a> using an access_type called <em>traverse</em> and also make use of a few
hook methods for giving feedback if the traversal fails. See <codeclass="docutils literal notranslate"><spanclass="pre">evennia.DefaultExit</span></code> for more info.
In <codeclass="docutils literal notranslate"><spanclass="pre">mygame/typeclasses/exits.py</span></code> there is an empty <codeclass="docutils literal notranslate"><spanclass="pre">Exit</span></code> class for you to modify.</p>
<li><p>The traversing <codeclass="docutils literal notranslate"><spanclass="pre">obj</span></code> sends a command that matches the Exit-command name on the Exit object. The
<aclass="reference internal"href="Commands.html"><spanclass="doc std std-doc">cmdhandler</span></a> detects this and triggers the command defined on the Exit. Traversal always
involves the “source” (the current location) and the <codeclass="docutils literal notranslate"><spanclass="pre">destination</span></code> (this is stored on the Exit
<li><p>In <codeclass="docutils literal notranslate"><spanclass="pre">at_traverse</span></code>, <codeclass="docutils literal notranslate"><spanclass="pre">object.move_to(destination)</span></code> is triggered. This triggers the following hooks,
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">obj.at_pre_move(destination)</span></code> - if this returns False, move is aborted.</p></li>
<li><p>Move is performed by changing <codeclass="docutils literal notranslate"><spanclass="pre">obj.location</span></code> from source location to <codeclass="docutils literal notranslate"><spanclass="pre">destination</span></code>.</p></li>
<li><p>On the Exit object, <codeclass="docutils literal notranslate"><spanclass="pre">at_post_traverse(obj,</span><spanclass="pre">source)</span></code> is triggered.</p></li>
<p>If the move fails for whatever reason, the Exit will look for an Attribute <codeclass="docutils literal notranslate"><spanclass="pre">err_traverse</span></code> on itself
and display this as an error message. If this is not found, the Exit will instead call
