<p>The <aclass="reference internal"href="../api/evennia.comms.models.html#evennia.comms.models.Msg"title="evennia.comms.models.Msg"><spanclass="xref myst py py-class">Msg</span></a> object represents a database-saved piece of communication. Think of it as a discrete piece of email - it contains a message, some metadata and will always have a sender and one or more recipients.</p>
<p>Once created, a Msg is normally not changed. It is persitently saved in the database. This allows for comprehensive logging of communications. Here are some good uses for <codeclass="docutils literal notranslate"><spanclass="pre">Msg</span></code> objects:</p>
<ulclass="simple">
<li><p>page/tells (the <codeclass="docutils literal notranslate"><spanclass="pre">page</span></code> command is how Evennia uses them out of the box)</p></li>
<li><p>messages in a bulletin board</p></li>
<li><p>game-wide email stored in ‘mailboxes’.</p></li>
</ul>
<divclass="admonition important">
<pclass="admonition-title">Important</p>
<p>A <codeclass="docutils literal notranslate"><spanclass="pre">Msg</span></code> does not have any in-game representation. So if you want to use them
to represent in-game mail/letters, the physical letters would never be
visible in a room (possible to steal, spy on etc) unless you make your
spy-system access the Msgs directly (or go to the trouble of spawning an
actual in-game letter-object based on the Msg)</p>
</div>
<divclass="versionchanged">
<p><spanclass="versionmodified changed">Changed in version 1.0: </span>Channels dropped Msg-support. Now only used in <codeclass="docutils literal notranslate"><spanclass="pre">page</span></code> command by default.</p>
<h2>Working with Msg<aclass="headerlink"href="#working-with-msg"title="Link to this heading">¶</a></h2>
<p>The Msg is intended to be used exclusively in code, to build other game systems. It is <em>not</em> a <aclass="reference internal"href="Typeclasses.html"><spanclass="std std-doc">Typeclassed</span></a> entity, which means it cannot (easily) be overridden. It doesn’t support Attributes (but it <em>does</em> support <aclass="reference internal"href="Tags.html"><spanclass="std std-doc">Tags</span></a>). It tries to be lean and small since a new one is created for every message.
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">senders</span></code> - there must always be at least one sender. This is a set of</p></li>
or <codeclass="docutils literal notranslate"><spanclass="pre">str</span></code> in any combination (but usually a message only targets one type).
Using a <codeclass="docutils literal notranslate"><spanclass="pre">str</span></code> for a sender indicates it’s an ‘external’ sender and
and can be used to point to a sender that is not a typeclassed entity. This is not used by default
and what this would be depends on the system (it could be a unique id or a
python-path, for example). While most systems expect a single sender, it’s
possible to have any number of them.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">receivers</span></code> - these are the ones to see the Msg. These are again any combination of
It’s in principle possible to have zero receivers but most usages of Msg expects one or more.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">header</span></code> - this is an optional text field that can contain meta-information about the message. For
an email-like system it would be the subject line. This can be independently searched, making
this a powerful place for quickly finding messages.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">message</span></code> - the actual text being sent.</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">date_sent</span></code> - this is auto-set to the time the Msg was created (and thus presumably sent).</p></li>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">locks</span></code> - the Evennia <aclass="reference internal"href="Locks.html"><spanclass="std std-doc">lock handler</span></a>. Use with <codeclass="docutils literal notranslate"><spanclass="pre">locks.add()</span></code> etc and check locks with <codeclass="docutils literal notranslate"><spanclass="pre">msg.access()</span></code>
<li><p><codeclass="docutils literal notranslate"><spanclass="pre">hide_from</span></code> - this is an optional list of <aclass="reference internal"href="Accounts.html"><spanclass="std std-doc">Accounts</span></a> or <aclass="reference internal"href="Objects.html"><spanclass="std std-doc">Objects</span></a> that
<p><aclass="reference internal"href="../api/evennia.comms.models.html#evennia.comms.models.TempMsg"title="evennia.comms.models.TempMsg"><spanclass="xref myst py py-class">evennia.comms.models.TempMsg</span></a> is an object that implements the same API as the regular <codeclass="docutils literal notranslate"><spanclass="pre">Msg</span></code>, but which has no database component (and thus cannot be searched). It’s meant to plugged into systems expecting a <codeclass="docutils literal notranslate"><spanclass="pre">Msg</span></code> but where you just want to process the message without saving it.</p>
