Question

I have a class that wraps a mongodb client for node.js. The the class below when I call findUsers I get that this.collection is undefined.

How do I access this.collection from the prototype?

Thank you!

Class:

var Users;

Users = (function () {

    function Users(db) {

        db.collection('users', function (err, collection) {
           this.collection = collection;
        });
    }

    Users.prototype.findUsers = function (callback) {

        this.collection.find({}, function (err, results) {

        });
    }

    return Users;

})();

Usage:

//db holds the db object already created
var user = new Users(db);
user.findUsers();

Answer 1

You are doing it right in the prototype method, your error is in the callback function of db.collection().

var Users = (function () {
    function Users(db) {
        var that = this; // create a reference to "this" object
        db.collection('users', function (err, collection) {
            that.collection = collection; // and use that
        });
    }
    Users.prototype.findUsers = function (callback) {
        this.collection.find({}, function (err, results) {

        });
    }
    return Users;
})();