Question

I understand how to use Protoype in standard Javascript with Node.js and modules, but am having a rough time equating them in CoffeeScript.

Let’s say I have a file called mymodule.coffee:

Module = {}

class MyModule

  constructor: (parameter) ->

    Module = this
    Module.parameter = parameter

  standardFunction = (parameter) ->

    return parameter

  callbackFunction = (parameter, callback) ->

    callback parameter

exports.MyModule = MyModule

And I have another file called test.coffee in the same directory, which I run via coffee test.coffee, but get an error TypeError: Object #<MyModule> has no method 'standardFunction' when trying to access the class MyModule:

myModule = require 'mymodule'
myModule = new myModule.MyModule 'parameter'

console.log myModule.standardFunction 'parameter'

myModule.callbackFunction 'parameter', (response) ->

  console.log 'Response: ' + response 

What am I doing wrong?

Answer 1

You have mistake in a syntax:

standardFunction = (parameter) ->
    return parameter

should be

standardFunction : (parameter) ->
    return parameter

(: instead of =) The first one is converted to

standardFunction = function(parameter) {
    return parameter;
}

which gives you nothing (no relation to class), while the second one to

MyModule.prototype.standardFunction = function(parameter) {
    return parameter;
}

which is what you want.

By the way, you can use CoffeeScript in your constructor like this:

constructor: (parameter) ->
    @parameter = parameter