Telegex

A new Telegram bot framework, which is also a perfect Bot API client library.

All API functions, comments, types (structures and specifications) of Telegex are generated from documents. I parse the documents into structured data and publish it on telegex/api_doc.json.

Introduction

Telegex is not only a client for Bot API, but also a framework for building bots. It provides convenient support for receiving updates and implements an advanced processing model based on "chains".

The section regarding chains currently has no documentation available. Join the group, communicate about Elixir and bot development: @elixir_telegex

Installation

Add Telegex to your mix.exs dependencies:

def deps do
  [
    {:telegex, "~> 1.1"},
  ]
end

Configuration

Add bot token to the secret configuration file, like this:

config :telegex, token: "<BOT_TOKEN>"

Specify the adapter for the HTTP client in the public configuration file:

config :telegex, caller_adapter: Finch

Pass options to the adapter, such as timeout:

config :telegex, caller_adapter: {Finch, [receive_timeout: 5 * 1000]}

You can also choose HTTPoison as the client. If using HTTPoison, set the corresponding adapter and timeout:

config :telegex, caller_adapter: {HTTPoison, [recv_timeout: 5 * 1000]}

Note: There are no standardized values for the options parameter here, as they directly relate to the HTTP client being used. The example above passes the raw options for the client library.

Note: You need to manually add adapter-related libraries to the deps:

Finch: finch, multipart (recommend)
HTTPoison: httpoison (⚠️ sending local files is not supported)

API call

All Bot APIs are located under the Telegex module, and these APIs fully comply with the required and optional parameters in the documentation, returning specific types (struct rather than map).

getMe

iex> Telegex.get_me
{:ok,
 %Telegex.Type.User{
   supports_inline_queries: false,
   can_read_all_group_messages: false,
   can_join_groups: true,
   added_to_attachment_menu: nil,
   is_premium: nil,
   language_code: nil,
   username: "telegex_dev_bot",
   last_name: nil,
   first_name: "Telegex Dev",
   is_bot: true,
   id: 6258629308
 }}

getUpdates

iex> Telegex.get_updates limit: 50
{:ok,
 [
   %Telegex.Type.Update{
     chat_join_request: nil,
     chat_member: nil,
     my_chat_member: nil,
     poll_answer: nil,
     poll: nil,
     pre_checkout_query: nil,
     shipping_query: nil,
     callback_query: nil,
     chosen_inline_result: nil,
     inline_query: nil,
     edited_channel_post: nil,
     channel_post: nil,
     edited_message: nil,
     message: %Telegex.Type.Message{
       reply_markup: nil,
       web_app_data: nil,
       # omitted part...
       new_chat_photo: nil,
       new_chat_title: nil,
       text: "Hello",
       # omitted part...
     },
     update_id: 929396006
   }
 ]}

sendMessage

iex> Telegex.send_message -1001486769003, "Hello!"
{:ok,
 %Telegex.Type.Message{
   venue: nil,
   chat: %Telegex.Type.Chat{
     # omitted part...
     title: "Dev test",
     type: "supergroup",
     id: -1001486769003
   },
   date: 1686111102,
   message_id: 12777,
   text: "Hello!",
   from: %Telegex.Type.User{
     supports_inline_queries: nil,
     can_read_all_group_messages: nil,
     can_join_groups: nil,
     added_to_attachment_menu: nil,
     is_premium: nil,
     language_code: nil,
     username: "telegex_dev_bot",
     last_name: nil,
     first_name: "Telegex Dev",
     is_bot: true,
     id: 6258629308
  }, 
  # omitted part...
 }}

Polling mode

Polling is a simple and effective pattern that ensures messages within the same group arrive in order. Although it may not be the fastest, it is simple and reliable.

To work in polling mode:

Create a new module, like YourProject.PollingHandler
Use Telegex.Polling.Handler
Implement on_boot/0 and on_update/1 callback functions
Add your module to the supervision tree

Polling handler example:

defmodule YourProject.PollingHandler do
  use Telegex.Polling.Handler

  @impl true
  def on_boot do
    # delete any potential webhook
    {:ok, true} = Telegex.delete_webhook()
    # create configuration (can be empty, because there are default values)
    %Telegex.Polling.Config{}
    # you must return the `Telegex.Polling.Config` struct ↑
  end

  @impl true
  def on_update(update) do
    # consume the update

    :ok
  end
end

Don't forget to add your module to the supervision tree.

Webhook mode

Add plug and remote_ip to your application's deps because they are required for webhook mode.

You also need to configure adapters for hooks, which provide web services.

Based on Bandit - bandit

# add `bandit` to your dpes.
config :telegex, hook_adapter: Bandit

Based on Cowboy - plug_cowboy

# add `plug_cowboy` to your dpes.
config :telegex, hook_adapter: Cowboy

To work in webhook mode:

Create a new module, like YourProject.HookHandler
Use Telegex.Hook.Handler
Implement on_boot/0 and on_update/1 callback functions
Add your module to the supervision tree

Hook handler example:

defmodule YourProject.HookHandler do
  use Telegex.Hook.Handler

  @impl true
  def on_boot do
    # read some parameters from your env config
    env_config = Application.get_env(:your_project, __MODULE__)
    # delete the webhook and set it again
    {:ok, true} = Telegex.delete_webhook()
    # set the webhook (url is required)
    {:ok, true} = Telegex.set_webhook(env_config[:webhook_url])
    # specify port for web server
    # port has a default value of 4000, but it may change with library upgrades
    %Telegex.Hook.Config{server_port: env_config[:server_port]}
    # you must return the `Telegex.Hook.Config` struct ↑
  end

  @impl true
  def on_update(update) do
  
    # consume the update
    :ok
  end
end