Add echo component briefing.

docs/getting_started/component.rst

@@ -1,2 +1,75 @@
+.. _echocomponent:
+
+=================================
 Create and Run a Server Component
 =================================
+
+.. note::
+
+    If you have any issues working through this quickstart guide
+    or the other tutorials here, please either send a message to the
+    `mailing list <http://groups.google.com/group/sleekxmpp-discussion>`_
+    or join the chat room at `sleek@conference.jabber.org
+    <xmpp:sleek@conference.jabber.org?join>`_.
+
+If you have not yet installed SleekXMPP, do so now by either checking out a version
+from `Github <http://github.com/fritzy/SleekXMPP>`_, or installing it using ``pip``
+or ``easy_install``.
+
+.. code-block:: sh
+
+    pip install sleekxmpp  # Or: easy_install sleekxmpp
+
+
+Many XMPP applications eventually graduate to requiring to run as a server 
+component in order to meet scalability requirements. To demonstrate how to 
+turn an XMPP client bot into a component, we'll turn the echobot example
+(:ref:`echobot`) into a component version.
+
+The first difference is that we will add an additional import statement:
+
+.. code-block:: python
+
+    from sleekxmpp.componentxmpp import ComponentXMPP
+
+Likewise, we will change the bot's class definition to match:
+
+.. code-block:: python
+
+    class EchoComponent(ComponentXMPP):
+
+        def __init__(self, jid, secret, server, port):
+            ComponentXMPP.__init__(self, jid, secret, server, port)
+
+A component instance requires two extra parameters compared to a client
+instance: ``server`` and ``port``. These specifiy the name and port of
+the XMPP server that will be accepting the component. For example, for
+a MUC component, the following could be used:
+
+.. code-block:: python
+
+    muc = ComponentXMPP('muc.sleekxmpp.com', '******', 'sleekxmpp.com', 5555)
+
+.. note::
+
+    The ``server`` value is **NOT** derived from the provided JID for the
+    component, unlike with client connections.
+
+One difference with the component version is that we do not have
+to handle the :term:`session_start` event if we don't wish to deal
+with presence.
+
+The other, main difference with components is that the
+``'from'`` value for every stanza must be explicitly set, since
+components may send stanzas from multiple JIDs. To do so,
+the :meth:`~sleekxmpp.basexmpp.BaseXMPP.send_message()` and
+:meth:`~sleekxmpp.basexmpp.BaseXMPP.send_presence()` accept the parameters
+``mfrom`` and ``pfrom``, respectively. For any method that uses
+:class:`~sleekxmpp.stanza.iq.Iq` stanzas, ``ifrom`` may be used.
+
+
+Final Product
+-------------
+
+.. include:: ../../examples/echo_component.py
+    :literal: