CODEWITHSUNDEEP
javascriptnode.jstypescripttypescript1.6
boop
boop

Reputation: 7788

NodeJS EventEmitter with TypeScript class

Is it possible to use NodeJS' events.EventEmitter with a TypeScript class? If yes, how?

I've tried countless variations in the last hours to get this working, so I won't list any of them.

What I basically want to do:

export class Database{
    constructor(cfg:IDatabaseConfiguration) {
        // events.EventEmitter.call(this); 
        mongoose.connect(cfg.getConnectionString(), cfg.getCredentials(), function (err:any) {
            if (err)
                this.emit('error', err);
            else
                this.emit('ready');
        });
    }
}

Upvotes: 25

Views: 34021

Answers (3)

Yuriy Gavrishov
Yuriy Gavrishov

Reputation: 5021

The modern way to download types definitions for NodeJS and EventEmitter particularly is:

npm install @types/node

or with yarn:

yarn add @types/node

Upvotes: 5

Dominik Palo
Dominik Palo

Reputation: 3111

New approach:

///<reference path="./typings/node/node.d.ts" />

import {EventEmitter} from 'events';

class Database extends EventEmitter {
    constructor() {
        super();
        this.emit('ready');
    }
}

new Database();

Upvotes: 32

MartyIX
MartyIX

Reputation: 28648

You should download node typings:

$ tsd install node --save

and then just use the following code:

///<reference path="./typings/node/node.d.ts" />
import events = require('events');

class Database{
    constructor() {
        events.EventEmitter.call(this);
    }
}

I simplified it to test your main problem.

Edit: Modified based on your comment:

///<reference path="./typings/node/node.d.ts" />
import events = require('events');

class Database extends events.EventEmitter {
    constructor() {
        super();
        this.emit('ready');
    }
}

new Database();

Upvotes: 23

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