Question

I am trying to learn how to use Node, Mongoose, and Mongo by looking at code from GitHub.

What’s the purpose of this line:

PostProvider = function(){};

from: https://github.com/cmarin/MongoDB-Node-Express-Blog/blob/master/postprovider.js

To me, it seems like an empty function.

Answer 1

To simulate the “class-concept” in javascript, we have 3 ways. One of this way is to use the prototype feature. Example for a Apple class :

function Apple (type) {
    this.type = type;
    this.color = "red";
}

Apple.prototype.getInfo = function() {
    return this.color + ' ' + this.type + ' apple';
};

In your example, the PostProvider function has no attributes. So, “cmarin” declares an empty function :

PostProvider = function() {};

And add some methods :

• PostProvider.prototype.findAll
• PostProvider.prototype.findById
• etc.