Question

CoffeeScript wraps variables declared inside methods in an object literal.

So, this:

@Templates =
    get: (templateName) ->
        result: ''              # DECLARED HERE
        $.ajax(
            'Views/Templates/' + templateName + '.html',
            type: 'GET'
            dataType: 'html'
            success: (data) ->
                result = data   # ASSIGNED HERE
            async: false
        )
        return result           # RETURNED HERE

Becomes this:

(function() {

  this.Templates = {
    get: function(templateName) {
      ({
        result: ''                  //DECLARED IN AN OBJECT LITERAL - I DON'T WANT THIS
      });
      $.ajax('Views/Templates/' + templateName + '.html', {
        type: 'GET',
        dataType: 'html',
        success: function(data) {
          var result;               //DECLARED LOCAL TO THE CALLBACK - I DON'T WANT THIS
          return result = data;
        },
        async: false
      });
      return result;                //RETURNED HERE - UNASSIGNED
    }
  };

}).call(this);

But what I need, and that works for me, is this:

(function() {

  this.Templates = {
    get: function(templateName) {
      var result = ''               //DECLARED HERE
      $.ajax('Views/Templates/' + templateName + '.html', {
        type: 'GET',
        dataType: 'html',
        success: function(data) {
          return result = data;     //ASSIGNED HERE
        },
        async: false
      });
      return result;                //RETURNED HERE
    }
  };

}).call(this);

What am I doing wrong? How can I fix this?

Answer 1

What you’ve called a closure isn’t a closure (closures in JavaScript are always functions). It’s an object literal wrapped in parentheses.

I’m not really au fait with CoffeeScript, but if you want result to be a local variable in the get function, I believe you want to change

result: ''

to

result = ''

The former is the object initializer format (hence it getting translated into an object literal), the latter is a variable assignment. Seems to be covered on the CoffeeScript site under lexical scoping.