Quick start

This chapter wants to get you started quickly with aioxmpp. It will spare you with most architectural and design details and simply throw some code snippets at you which do some work.

Note

Even though aioxmpp does technically not require it, we will use PEP 492 features throughout this chapter.

It makes the code much more concise at some points; there are (currently) always ways around having to use PEP 492 features—please refer to the examples along with the source code to see alternatives e.g. for connecting.

In this section, we will assume that you are familiar with the basic concepts of XMPP. If you are not, you may still try to walk through this, but a lot of things which are obvious when you are used to work with XMPP will not be explained.

Preparations

We assume that you have both a aioxmpp.JID and a password as str at hand. One way to obtain would be to ask the user:

jid = aioxmpp.JID.fromstr(input("JID: "))
password = getpass.getpass()

Note

getpass is a standard Python module for blockingly asking the user for a password in a terminal. You can use different means of obtaining a password. Most importantly, in this tutorial, you could replace password with a coroutine taking two arguments, a aioxmpp.JID and an integer; the integer would increase with every authentication attempt during a connection attempt (starting at 0). The caller expects that the coroutine returns a password to try, or None to abort the authentication.

In fact, passing a str as password below simply makes the code wrap that str in a coroutine which returns the str when the second argument is zero and None otherwise.

Connect to an XMPP server, with JID and Password

To connect to an XMPP server, we use a aioxmpp.PresenceManagedClient:

client = aioxmpp.PresenceManagedClient(
    jid,
    aioxmpp.make_security_layer(password)
)

async with client.connected() as stream:
    ...

At ..., the client is connected and has sent initial presence with an available state. We will get back to the stream object returned by the context manager later on.

Relevant documentation:

Send a message

We assume that you did the part from the previous section, and we’ll now work inside the async with block:

msg = aioxmpp.Message(
    to=recipient_jid,  # recipient_jid must be an aioxmpp.JID
    type_=aioxmpp.MessageType.CHAT,
)
# None is for "default language"
msg.body[None] = "Hello World!"

await stream.send(msg)

Relevant documentation:

Note

Want to send an IQ instead? IQs are a bit more complex, due to their rather formal nature. We suggest that you read through this quickstart step-by-step, but you may as well jump ahead to Send a custom IQ payload.

Change presence

aioxmpp.PresenceManagedClient.connected() automatically sets an available presence. To change presence during runtime, there are two ways:

# the simple way: simply set to Do-Not-Disturb
client.presence = aioxmpp.PresenceState(available=True, show="dnd")

# the advanced way: change presence and set the textual status
client.set_presence(
    aioxmpp.PresenceState(available=True, show="dnd"),
    "Busy with stuff",
)

Relevant documentation:

React to messages (Echo Bot)

Of course, you can react to messages. For this, you need to register with the aioxmpp.stream.StanaStream of the client. You better do this before connecting, to avoid race conditions. So the following code should run before the async with. To get all chat messages, you could use:

def message_received(msg):
    print(msg)

client.stream.register_message_callback(
    aioxmpp.MessageType.CHAT,
    None,
    message_received,
)

The message_received callback will be called for all "chat" messages from any sender. By itself, it is not very useful, because the msg argument is the aioxmpp.Message object.

This example can be modified to be an echo bot by implementing the message_received callback differently:

def message_received(msg):
    if not msg.body:
        # do not reflect anything without a body
        return

    reply = msg.make_reply()
    reply.body.update(msg.body)

    client.stream.enqueue(reply)

Note

A slightly more verbose version can also be found in the examples directory, as quickstart_echo_bot.py.

React to presences

Similar to handling messages, presences can also be handled.

Note

There exists a service which handles and manages peer presence (aioxmpp.PresenceClient) and one which manages roster subscriptions (aioxmpp.RosterClient), which make most manual handling of presence obsolete. Read on on how to use services.

Again, the code should be run before connected():

def available_presence_received(pres):
    print(pres)

client.stream.register_presence_callback(
    aioxmpp.PresenceType.AVAILABLE,
    None,
    available_presence_received,
)

Again, the whole aioxmpp.Presence stanza is passed to the callback.

Relevant documentation:

React to IQ requests

Reacting to IQ requests is slightly more complex. The reason is that a client must always reply to IQ requests. Thus, it is most natural to use coroutines as IQ request handlers, instead of normal functions:

async def request_handler(request):
    print(request)

client.stream.register_iq_request_coro(
    aioxmpp.IQType.GET,
    aioxmpp.disco.xso.InfoQuery,
    request_handler,
)

The coroutine is spawned for each request. The coroutine must return a valid value for the aioxmpp.IQ.payload attribute, or raise an exception, ideally one derived from aioxmpp.errors.XMPPError. The exception will be converted to a proper "error" IQ response.

Relevant documentation:

Use services

Services have now been mentioned several times. The idea of a aioxmpp.service.Service is to implement a specific XEP or an optional part of the XMPP protocol. Services essentially do the same thing as discussed in the previous sections (sending and receiving messages, IQs and/or presences), but encapsulated away in a class. For details on that, see aioxmpp.service and an implementation, such as aioxmpp.DiscoClient.

Here we’ll show how to use services:

client = aioxmpp.PresenceManagedClient(
    jid,
    aioxmpp.make_security_layer(password)
)

disco = client.summon(aioxmpp.DiscoClient)

async with client.connected() as stream:
    info = await disco.query_info(
        target_jid,
    )

In this case, info is a aioxmpp.disco.xso.InfoQuery object returned by the entity identified by target_jid.

The idea of services is to abstract away the details of the protocol implemented, and offer additional features (such as caching). Several services are offered by aioxmpp, the easiest way to find those is to simply check the API Reference; most XEPs supported by aioxmpp are implemented as services.

Relevant docmuentation:

Use aioxmpp.PresenceClient presence implementation

This section is mainly there to show you a service which is mostly used with callbacks:

client = aioxmpp.PresenceManagedClient(
    jid,
    aioxmpp.make_security_layer(password)
)

def peer_available(jid):
    print("{} came online".format(jid))

def peer_unavailable(jid):
    print("{} went offline".format(jid))

presence = client.summon(aioxmpp.PresenceClient)
presence.on_bare_available.connect(peer_available)
presence.on_bare_unavailable.connect(peer_unavailable)

async with client.connected() as stream:
    await asyncio.sleep(10)

This simply stays online for ten seconds and prints the bare JIDs from which available and unavailable presence is received.

Relevant documentation:

Send a custom IQ payload

As mentioned earlier, IQs are a bit more complex. IQ payloads are more or less strictly defined, which gives aioxmpp the opportunity to take the load of data validation off your back. This also means that you need to tell aioxmpp what format you expect.

We will take XEP-0092 (Software Version) as an example. First we need to define the IQ payload. You would generally do that in a module you import in your application:

import aioxmpp
import aioxmpp.xso as xso

namespace = "jabber:iq:version"

@aioxmpp.IQ.as_payload_class
class Query(xso.XSO):
    TAG = (namespace, "query")

    name = xso.ChildText(
        (namespace, "name"),
        default=None,
    )

    version = xso.ChildText(
        (namespace, "version"),
        default=None,
    )

    os = xso.ChildText(
        (namespace, "os"),
        default=None,
    )

XSO is a base class for any element occurring in an XMPP XML stream. Using declarative-style descriptors, we describe the children we expect on the XEP-0092 query. There are of course other descriptors, for example for attributes, lists of children declared as classes, even dictionaries. See the relevant documentation below for details.

With that declaration, we can construct and send a XEP-0092 IQ like this (we are now back inside the async with block):

iq = aioxmpp.IQ(
    type_=aioxmpp.IQType.GET,
    payload=Query(),
    to=peer_jid,
)

print("sending query to {}".format(peer_jid))
reply = await stream.send(iq)
print("got response!")

If the peer complies with the protocol, reply is an instance of our freshly baked Query! The attributes will contain the response from the peer, we could print them like this:

print("name: {!r}".format(reply.name))
print("version: {!r}".format(reply.version))
print("os: {!r}".format(reply.os))

(Note that we passed default=None to the aioxmpp.xso.ChildText descriptor objects above; otherwise, accessing a descriptor representing something which was not sent by the peer would result in a AttributeError, just like any other not-set attribute).

Relevant documentation:

Note

In general, before considering sending an IQ manually, you should check out the Protocol part and XEP implementations section of the API to see whether there is a module handling the XEP or RFC for you.

Note

The example in this section can also be found in the aioxmpp repository, at examples/quickstart_query_server_version.py.

React to an IQ request

We build on the previous section. This time, we want to stay online for 30 seconds and serve software version requests.

To do this, we register a coroutine to handle IQ requests (before the async with):

async def handler(iq):
    print("software version request from {!r}".format(iq.from_))
    result = Query()
    result.name = "aioxmpp Quick Start Pro"
    result.version = "23.42"
    result.os = "MFHBμKOS (My Fancy HomeBrew Micro Kernel Operating System)"
    return result

client.stream.register_iq_request_coro(
    aioxmpp.IQType.GET,
    Query,
    handler,
)

async with client.connected():
    await asyncio.sleep(30)

While the client is online, it will respond to IQ requests of type "get" which carry a Query payload; the payload is identified by its qualified XML name (that is, the namespace and element name tuple). aioxmpp was made aware of the Query using the aioxmpp.IQ.as_payload_class() descriptor.

It then calls the handler coroutine we declared with the aioxmpp.IQ object as its only argument. The coroutine is expected to return a valid payload (hint: None is also a valid payload) for the "result" IQ or raise an exception (which would be converted to an "error" IQ).

Relevant documentation:

Next steps

This quickstart should have given you an impression on how to use aioxmpp for rather simple tasks. If you develop a complex application, you might want to look into the more advanced topics in the following chapters of the user guide.