Using node module in angularjs?

Question

What's the best practice for using external code, e.g. code found in node modules, in angular?

I'd like to use this https://www.npmjs.com/package/positionsizingcalculator node module in my angular app. I've created an angular service intended to wrap the node module, and now I want to make the service use the node module.

'use strict';

angular.module('angularcalculator')
  .service('MyService', function () {
    this.calculate = function () {
      return {
        //I want to call the node module here, whats the best practice?
      };
    }
  });

Answer 1

To do this, I would crack open the package and grab the .js out of it. This package is MIT license, so we can do whatever we want. If you navigate to /node_modules/positionsizingcalculator/ you'll find an index.js. Open that up and you'll see the moudle export, which takes a function that returns an object.

You'll notice this is an extremely similar pattern to .factory, which also takes a function that returns an object (or constuctor, depending on your pattern). So I'd do the following

.factory('positionsizingcalculator', function(){
        basicValidate = function (argument) {
        ... //Insert whole declaration in here
        return position;
}) 

and the inject it where you need it:

.controller('AppController', function(positionsizingcalculator){
    //use it here as you would in node after you inject it via require.
})

-- Edit: This is good for one off grabs of the JS, but if you want a more extensible solution, http://browserify.org/ is a better bet. It allows you to transform your requirements into a single package. Note that this could result in pulling down a lot more code that you might otherwise need, if you make one require bundle for your whole site, as this is not true AMD, and you need to to load everything you might want one the client, unless you make page specific bundles.

You'd still want to do the require in a factory and return it, to keep it in angular's dependency injection framework.