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Diffstat (limited to 'docs/getting_started/iq.rst')
| -rw-r--r-- | docs/getting_started/iq.rst | 55 |
1 files changed, 29 insertions, 26 deletions
diff --git a/docs/getting_started/iq.rst b/docs/getting_started/iq.rst index be15e170..aac75712 100644 --- a/docs/getting_started/iq.rst +++ b/docs/getting_started/iq.rst @@ -3,7 +3,7 @@ Send/Receive IQ Stanzas Unlike :class:`~slixmpp.stanza.message.Message` and :class:`~slixmpp.stanza.presence.Presence` stanzas which only use -text data for basic usage, :class:`~slixmpp.stanza.iq.Iq` stanzas +text data for basic usage, :class:`~slixmpp.stanza.Iq` stanzas require using XML payloads, and generally entail creating a new Slixmpp plugin to provide the necessary convenience methods to make working with them easier. @@ -11,7 +11,7 @@ make working with them easier. Basic Use --------- -XMPP's use of :class:`~slixmpp.stanza.iq.Iq` stanzas is built around +XMPP's use of :class:`~slixmpp.stanza.Iq` stanzas is built around namespaced ``<query />`` elements. For clients, just sending the empty ``<query />`` element will suffice for retrieving information. For example, a very basic implementation of service discovery would just @@ -26,7 +26,7 @@ need to be able to send: Creating Iq Stanzas ~~~~~~~~~~~~~~~~~~~ -Slixmpp provides built-in support for creating basic :class:`~slixmpp.stanza.iq.Iq` +Slixmpp provides built-in support for creating basic :class:`~slixmpp.stanza.Iq` stanzas this way. The relevant methods are: * :meth:`~slixmpp.basexmpp.BaseXMPP.make_iq` @@ -37,7 +37,7 @@ stanzas this way. The relevant methods are: * :meth:`~slixmpp.basexmpp.BaseXMPP.make_iq_query` These methods all follow the same pattern: create or modify an existing -:class:`~slixmpp.stanza.iq.Iq` stanza, set the ``'type'`` value based +:class:`~slixmpp.stanza.Iq` stanza, set the ``'type'`` value based on the method name, and finally add a ``<query />`` element with the given namespace. For example, to produce the query above, you would use: @@ -50,18 +50,16 @@ namespace. For example, to produce the query above, you would use: Sending Iq Stanzas ~~~~~~~~~~~~~~~~~~ -Once an :class:`~slixmpp.stanza.iq.Iq` stanza is created, sending it -over the wire is done using its :meth:`~slixmpp.stanza.iq.Iq.send()` +Once an :class:`~slixmpp.stanza.Iq` stanza is created, sending it +over the wire is done using its :meth:`~slixmpp.stanza.Iq.send()` method, like any other stanza object. However, there are a few extra -options to control how to wait for the query's response. +options to control how to wait for the query's response, as well as +how to handle the result. -These options are: +:meth:`~slixmpp.stanza.Iq.send()` returns an :class:`~asyncio.Future` +object, which can be awaited on until a ``result`` is received. -* ``block``: The default behaviour is that :meth:`~slixmpp.stanza.iq.Iq.send()` - will block until a response is received and the response stanza will be the - return value. Setting ``block`` to ``False`` will cause the call to return - immediately. In which case, you will need to arrange some way to capture - the response stanza if you need it. +These options are: * ``timeout``: When using the blocking behaviour, the call will eventually timeout with an error. The default timeout is 30 seconds, but this may @@ -79,28 +77,33 @@ These options are: * ``callback``: When not using a blocking call, using the ``callback`` argument is a simple way to register a handler that will execute - whenever a response is finally received. Using this method, there - is no timeout limit. In case you need to remove the callback, the - name of the newly created callback is returned. + whenever a response is finally received. .. code-block:: python - cb_name = iq.send(callback=self.a_callback) + iq.send(callback=self.a_callback) + +* ``timeout_callback``: A callback to execute when the provided + ``timeout`` is reached before an answer is received. + + +.. note:: - # ... later if we need to cancel - self.remove_handler(cb_name) + Both ``callback`` and ``timeout_callback`` can be effectively + replaced using ``await``, and standard exception handling + (see below), which provide a more linear and readable workflow. -Properly working with :class:`~slixmpp.stanza.iq.Iq` stanzas requires +Properly working with :class:`~slixmpp.stanza.Iq` stanzas requires handling the intended, normal flow, error responses, and timed out requests. To make this easier, two exceptions may be thrown by -:meth:`~slixmpp.stanza.iq.Iq.send()`: :exc:`~slixmpp.exceptions.IqError` +:meth:`~slixmpp.stanza.Iq.send()`: :exc:`~slixmpp.exceptions.IqError` and :exc:`~slixmpp.exceptions.IqTimeout`. These exceptions only apply to the default, blocking calls. .. code-block:: python try: - resp = iq.send() + resp = await iq.send() # ... do stuff with expected Iq result except IqError as e: err_resp = e.iq @@ -116,7 +119,7 @@ exception: .. code-block:: python try: - resp = iq.send() + resp = await iq.send() except XMPPError: # ... Don't care about the response pass @@ -126,7 +129,7 @@ Advanced Use Going beyond the basics provided by Slixmpp requires building at least a rudimentary Slixmpp plugin to create a :term:`stanza object` for -interfacting with the :class:`~slixmpp.stanza.iq.Iq` payload. +interfacting with the :class:`~slixmpp.stanza.Iq` payload. .. seealso:: @@ -135,13 +138,13 @@ interfacting with the :class:`~slixmpp.stanza.iq.Iq` payload. * :ref:`using-handlers-matchers` -The typical way to respond to :class:`~slixmpp.stanza.iq.Iq` requests is +The typical way to respond to :class:`~slixmpp.stanza.Iq` requests is to register stream handlers. As an example, suppose we create a stanza class named ``CustomXEP`` which uses the XML element ``<query xmlns="custom-xep" />``, and has a :attr:`~slixmpp.xmlstream.stanzabase.ElementBase.plugin_attrib` value of ``custom_xep``. -There are two types of incoming :class:`~slixmpp.stanza.iq.Iq` requests: +There are two types of incoming :class:`~slixmpp.stanza.Iq` requests: ``get`` and ``set``. You can register a handler that will accept both and then filter by type as needed, as so: |