Telethon/readthedocs/extra/advanced-usage/accessing-the-full-api.rst
Lonami Exo b716c4fe67 Several documentation enhancements and build warnings fixes
- Made the documentation even more friendly towards newbies.
- Eased the usage of methods like get history which now set
  a default empty message for message actions and vice versa.
- Fixed some docstring documentations too.
- Updated the old normal docs/ to link back and forth RTD.
- Fixed the version of the documentation, now auto-loaded.
2018-01-20 11:47:17 +01:00

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.. _accessing-the-full-api:
======================
Accessing the Full API
======================
The ``TelegramClient`` doesn't offer a method for every single request
the Telegram API supports. However, it's very simple to *call* or *invoke*
any request. Whenever you need something, don't forget to `check the
documentation`__ and look for the `method you need`__. There you can go
through a sorted list of everything you can do.
.. note::
The reason to keep both https://lonamiwebs.github.io/Telethon and this
documentation alive is that the former allows instant search results
as you type, and a "Copy import" button. If you like namespaces, you
can also do ``from telethon.tl import types, functions``. Both work.
You should also refer to the documentation to see what the objects
(constructors) Telegram returns look like. Every constructor inherits
from a common type, and that's the reason for this distinction.
Say ``client.send_message()`` didn't exist, we could use the `search`__
to look for "message". There we would find `SendMessageRequest`__,
which we can work with.
Every request is a Python class, and has the parameters needed for you
to invoke it. You can also call ``help(request)`` for information on
what input parameters it takes. Remember to "Copy import to the
clipboard", or your script won't be aware of this class! Now we have:
.. code-block:: python
from telethon.tl.functions.messages import SendMessageRequest
If you're going to use a lot of these, you may do:
.. code-block:: python
from telethon.tl import types, functions
# We now have access to 'functions.messages.SendMessageRequest'
We see that this request must take at least two parameters, a ``peer``
of type `InputPeer`__, and a ``message`` which is just a Python
``str``\ ing.
How can we retrieve this ``InputPeer``? We have two options. We manually
`construct one`__, for instance:
.. code-block:: python
from telethon.tl.types import InputPeerUser
peer = InputPeerUser(user_id, user_hash)
Or we call ``.get_input_entity()``:
.. code-block:: python
peer = client.get_input_entity('someone')
When you're going to invoke an API method, most require you to pass an
``InputUser``, ``InputChat``, or so on, this is why using
``.get_input_entity()`` is more straightforward (and often
immediate, if you've seen the user before, know their ID, etc.).
If you also need to have information about the whole user, use
``.get_entity()`` instead:
.. code-block:: python
entity = client.get_entity('someone')
In the later case, when you use the entity, the library will cast it to
its "input" version for you. If you already have the complete user and
want to cache its input version so the library doesn't have to do this
every time its used, simply call ``.get_input_peer``:
.. code-block:: python
from telethon import utils
peer = utils.get_input_user(entity)
.. note::
Since ``v0.16.2`` this is further simplified. The ``Request`` itself
will call ``client.get_input_entity()`` for you when required, but
it's good to remember what's happening.
After this small parenthesis about ``.get_entity`` versus
``.get_input_entity``, we have everything we need. To ``.invoke()`` our
request we do:
.. code-block:: python
result = client(SendMessageRequest(peer, 'Hello there!'))
# __call__ is an alias for client.invoke(request). Both will work
Message sent! Of course, this is only an example. There are nearly 250
methods available as of layer 73, and you can use every single of them
as you wish. Remember to use the right types! To sum up:
.. code-block:: python
result = client(SendMessageRequest(
client.get_input_entity('username'), 'Hello there!'
))
.. note::
Note that some requests have a "hash" parameter. This is **not**
your ``api_hash``! It likely isn't your self-user ``.access_hash`` either.
It's a special hash used by Telegram to only send a difference of new data
that you don't already have with that request, so you can leave it to 0,
and it should work (which means no hash is known yet).
For those requests having a "limit" parameter, you can often set it to
zero to signify "return default amount". This won't work for all of them
though, for instance, in "messages.search" it will actually return 0 items.
__ https://lonamiwebs.github.io/Telethon
__ https://lonamiwebs.github.io/Telethon/methods/index.html
__ https://lonamiwebs.github.io/Telethon/?q=message
__ https://lonamiwebs.github.io/Telethon/methods/messages/send_message.html
__ https://lonamiwebs.github.io/Telethon/types/input_peer.html
__ https://lonamiwebs.github.io/Telethon/constructors/input_peer_user.html