Telegram Needy

---

Telegram needy is an extention to node-telegram-bot-api and needjs which will give you the benefits of needs inside your telegram bots.

Install

$ npm install --save telegram-needy

Usage

const tgneedy = require('telegram-needy');

// Replace the value with your token
const token = 'YOUR_TELEGRAM_BOT_TOKEN';

const sys = new tgneedy({
    token: token
});

const bot = sys.bot;
const Need = sys.Need;

sys.register(new Need.Send({
    name: 'goodbye',
    text: 'Good bye\nHave fun!'
}));

sys.register(new Need.Ask({
    name: 'fave',
    text: 'What is your favorite thing about needjs?'
}));

sys.register(new Need.Choose({
    name: 'experience',
    text: 'Do you have any previous experience with needjs?',
    options: ['yes', 'no']
}));

sys.register(new Need({
    name: 'main',
    req: ['goodbye', 'experience', 'fave'],
    post: function(inputs){
        // To access the result of a previously satisfied need you should
        // call inputs['NeedName']
        console.log('user has experience?' + inputs['experience']);
        console.log('user\'s favorite thing?' + inputs['fave']);
        this.done();
    }
}));

bot.onText(/\/start/, (msg, match)=>{
    sys.trigger(msg.chat.id, 'main');
});

A Need Should have the following properties:

• name: name of the need.
• post: A function that will be called in order to satisfy the need. (See bellow for furthure information)

and each Need could have the following properties:

• req: An array of need names to indicate which needs should be satisfied before calling the post function.
• pre: A function that will be called before any of the req uired needs. (See bellow for furthure information)
• invokers: An array of event listeners. See bellow for more information.

There are a few extended needs you can use in needjs:

• Need.OneOf could be used in the req array ONLY. When it is used the system will try to satisfy one the needs starting from left.

There are a few extended needs in telegram-needy:

• Need.Send should be used inside register. This accepts an additional parameter text that will be sent to the user when calling the post function.
• Need.Ask Like Send this will also accept a text parameter that will be sent upon calling the pre function and when the user replies it will be satisfied with the user's respond as it's value.
• Need.Choose Like ask but the users repond MUST be one of the options provided inside options.

Events

Your needs could listen to events that are emitted by the node-telegram-bot-api while they are not satisfied. To do so you should append a invokers field to your need in this way:

sys.register(new Need({
    ...
    invokers: [
        {
            event: "event Name",
            callback : function(inputs, data){
               ....
            }
        }
    ]
}))

invokers is an array of objects who have event and callback.event could be a string or an array of strings, while callback is a function as described bellow.

Your events will be invoked as long as they are not satisfied. If satisfied in order for them to be invoked again the system must forget their value.

Functions

There are 3 kinds of functions in the needjs enviornment:

• post(inputs, [respond])
• pre(inputs)
• callback(inputs, eventData)

Inside any of these functions you MUST call one of the following functions. Not calling them inside your functions will result in unexpected behaviour.

• this.done([value]) tell the system that this need is satisfied and the resulting value of this need is value. This is optional if you don't have any valu eyou can call this.done() and the sysem will assign true to it.
• this.fail() tell the system that this need has failed and it should look for a way to recover. If the system can not find a way (for example inside a Need.OneOf) it will throw an error.
• this.wait() tell the system that this need needs time inorder to decide if it can be satisfied or not. Usually you want to use this inside the post of needs that require a certain event to be invoked.
• this.ok() tell the system that I'm done and I have nothing to do for now. (Used mostly inside pre, has it's usage in post but is completly useless inside callback).

NOTE: The Ask and Choose functions could have an optional post, which has an extra parameter called respond, which includes the user's respond.

Using different bot library

It is possible to use an extention of the node-telegram-bot-api. You could use libraries like tgfancy or bot-brother. To do so create your bot and give the tgneedy options a bot parameter like this:

const CustomBot = require('custom-bot-library');

bot = new CustomBot({
    ...
});

var sys = new tgneedy({
    bot: bot
});

You should either assign bot or token. Assigning both bot and token will result in the system using the default node-telegram-bot-api.

Using a different store

By default telegram-needy uses the MemoryStore in needmanager. You could however use any express-session comptaible store. Full list. To use a different store, do this:

var CustomStore = require('custom-store-library');
var store = new CustomStore(...);

var sys = new tgneedy({
    ...
    store: my_store
})