How to manage state and scenes#

Installation#

Before you begin, you need to install the library and initiate the bot; this process is described in detail here: How to import the library and initiate your bot.

How to manage user state#

By default, this library stores state in a key-value map. The key can be any string, any object can be the value. The state identifier is a combination of the chat identifier and the sender identifier, that is, each combination of chatId + senderId will have a separate state.

As an example, a simple bot was created to simulate user registration. To save a string in state, use the construction ctx.session.{var_name} = "string example".

Link to example: state-bot.js.

const WhatsAppBot = require('@green-api/whatsapp-bot')

const session = WhatsAppBot.session
const Stage = WhatsAppBot.Stage
const Scene = WhatsAppBot.BaseScene

const bot = new WhatsAppBot({
     idInstance: "{{INSTANCE_ID}}",
     apiTokenInstance: "{{TOKEN}}",
})

const loginScene = new Scene("loginScene")
loginScene.enter((ctx) => ctx.reply("Hi! This bot is an example of using state.\nPlease enter your login:"))
loginScene.on("text", (ctx) => {
   const login = ctx.message.text
     if (login && login.length >= 6 && login.length <= 12) {
         ctx.session.login = login
         ctx.reply("Login \"" + login + "\" - successfully saved.\nCreate a password:")
         ctx.scene.enter("passwordScene")
     } else {
         ctx.reply("Login must be from 6 to 12 characters")
     }
})
loginScene.on("message", (ctx) => {
     ctx.reply("Message must contain text!")
})

const passwordScene = new Scene("passwordScene")
passwordScene.on("text", (ctx) => {
     const password = ctx.message.text
     if (password && password.length >= 6 && password.length <= 12) {
         ctx.session.password = password
         ctx.reply("Success! Your login: " + ctx.session.login + "\nYour password: " + ctx.session.password)
         ctx.scene.leave()
     } else {
         ctx.reply("Password must be between 6 and 12 characters")
     }
})

const stage = new Stage([loginScene, passwordScene])      //registration of scenes
bot.use(session())                                        //initiating a session handler
bot.use(stage.middleware())                               //initiating the scene handler
bot.on('message', (ctx) => ctx.scene.enter('loginScene')) //activate the first scene
bot.launch()                                              //launch the bot

List of examples#

Description	Link to example
How to initialize a handler	hello-bot.js
Scene "Echo"	echo-bot.js
How to filter by notification type	media-bot.js
How to filter by message text	filter-bot.js
How to work with bot state	state-bot.js
Example of a ready-made chat bot	demo-bot