Yata (Yet another Telegram API)

A lightweight library for communication with the Telegram Bot Api.
To create a bot and get an api token, call the @BotFather.

TL;DR

npm install --save yata

const yata = require('yata')

// Polling is NOT supported at the moment
const bot = new yata({
  token: BOT_API_TOKEN,
  webhook: {
    url: YOUR_DOMAIN
  }
})

// send a message
// for available methods see here: https://core.telegram.org/bots/api#available-methods
bot.call('sendMessage', {chat_id: SOME_ID, text: 'Some Text'})
  .then((response) => {console.log(response)})

// listen to messages
bot.on('/start', (msg) => {
  bot.call('sendMessage', {chat_id: msg.from.id, text: 'Heyho - Welcome to this bot'})
})

// pattern also work
// imagine someone writes "@MyBot is so much cooler than yours"
bot.on(/@(.+)bot/i, (msg, match) {
  bot.call('sendMessage', {
    chat_id: msg.from.id,
    text: `I dont think that ${match[0]} is up to discussion at the moment`
  })
})

// multiple choice
bot.on(['/start', /start/i, 'go'], () => {...})

// every message
bot.on('*', (msg) => {...})

// in case you dont use arrow functions you can also use `this` which equals `bot`
bot.on('*', function(msg) {
  this.call('sendMessage', {...})
})

Modify messages before they hit your regular code

// modify the message
bot.mod((update) => {
  let msg = update.message
  msg.text = msg.text.toUpperCase()
  return update
})

// load stuff async
// if you dont like how hacky this is, scroll down to "Sessions"
bot.mod(async (update) => {
  let msg = update.message
  msg.user = await loadUser(msg.from.id)
  return update
})

// cancel the request
bot.mod(() => {
  throw new Error('This was request is not allowed')
})

Events

Beside the text there are many update and message events you can bind to. Message events get passed a message and update events the content of its update update.

To bind to an update event use bot.onUpdate(updateType, handler) or bot.on(updateType, handler, 'update').
Same goes for a message event: bot.onMessage(messageType, handler) or bot.on(updateType, handler, 'message').

Update-Events

• message
• edited_message
• channel_post
• edited_channel_post
• inline_query
• chosen_inline_result
• callback_query
• shipping_query
• pre_checkout_query

Message-Events

Literally anything you can send via telegram

• 'text', 'audio', 'document', 'game', 'photo', 'sticker', 'video', 'voice', 'video_note',
• 'contact', 'location', 'venue', 'new_chat_members', 'left_chat_member', 'new_chat_title',
• 'new_chat_photo', 'delete_chat_photo', 'group_chat_created', 'supergroup_chat_created',
• 'channel_chat_created', 'migrate_to_chat_id', 'migrate_from_chat_id', 'pinned_message',
• 'invoice', 'successful_payment'

Options

You can pass other options to the yata constructor

• log: false or a function which has the same signatur as console.log(...args) (default)
• token: Your API token
• webhook {
  • url: Your domain
  • host: 0.0.0.0
  • port: 443
  • key: Needed for https server
  • cert: Needed for https server
  • allowed_updates: [], Specifies which updates are pushed to your endpoint (see Update-Events for possible values)
  • max_connections: 40
  • open: true, autoopens the websocket*
  • server: See below**
• }

* In case you disable the autoopen feature you need to start it manually with bot.setupWebhook()
** When you pass true, its assumed that you setup the endpoint yourself (which is yourdomain.example/API_TOKEN).
To pass an update into the library call bot.updateState(jsonbody)
This is only useful when you use the server for other things as well (e.g. a website made with express)

API

const bot = new yata(...)

bot.call(apiMethod, params, pluginoptions)

Calls the specified method of the api with the given params. Returns a promise which resolves to the result or rejects with an error.

You can see all methods at the telegram api doc: https://core.telegram.org/bots/api#available-methods

bot.setErrorHandler(fn)

Whenever a bot.call() failes you can of course catch the rejected promise. However sometimes its useful to have a global handler which is called when a call is not successful. setErrorHandler allows that. The function passed needs the signature (method, params, response)

bot.setupWebhook()

Only needed when you disable the open option of the webhook. Call it, when your server is ready for incoming messages.

Example:

const router = require('someRouterFramework')

router.on('/API_TOKEN', (req) => {
  bot.updateState(req.body.toJSON())
})

router.listen(port, () => bot.setupWebhook())

bot.mod(handler)

Add a method which is called on every update. Note it is first-come first-serve. So the mods are executed in the order in which you added them. You can do asyncronous operations in the mod method by returning a Promise. However always resolve to the update variable which was passed:

bot.mod((update) => {
  // with promise
  return new Promise((resolve, reject) => resolve(update))
  
  // without
  return updates
})

bot.plugin(handler)

Plugins let you alter requests before they are send out. A plugin function is called with options = { method, params, plugin } (every argument passed to call) and needs to return an object of the same format. This way you can easily add functionality e.g. asking the user for something:

const asks = {}

bot.plugin((options) => {
  if(options.plugin.ask) {
    asks[options.params.chat_id] = options.plugin.ask
  }
  return options
})

bot.onMessage('text', (msg) => {
  if(asks[msg.from.id]) {
    bot.emitMessage('ask.' + asks[msg.from.id], msg)
    delete asks[msg.from.id]
  }
})

bot.on('/foo', async (msg, match) => {
  return bot.call('sendMessage', {chat_id: msg.from.id, text: 'Enter foo'}, { ask: 'foo' })
})

bot.onMessage('ask.foo', async (msg) => {
  // answer to the question
  console.log(msg.text)
})

bot.on(event, handler, type = 'text')

You can bind events to update, message and text. Update-Events have the names specified above, Message-Events are listed here. A text event can be anything the user writes to the bot (thats why this is all seperated because a user could just write channel_post which would otherwise trigger the message event channel_post).

bot.onUpdate, bot.onMessage, bot.onText

Shortcuts for on(event, handler, update||message||text)