I have a Javascript function with a namespace and I am using Prototype to execute a function. Example code:

GUI.Title = {
 initialise: function() {
  var elements = $$('a');

  this.show(); /* now it refers to the namespace */

  elements.each(function(element) {
   this.show(); /* this refers to the window object, not to the namespace */
  });

},
 show: function() {
  element.show();
 }
}

'this' refers to the namespace outside the each-function and inside the each it refers to the window.

Can someone explain to me how I can use 'this' in the each-loop as a referer to the namespace?

I am using Prototype.

I have a Javascript function with a namespace and I am using Prototype to execute a function. Example code:

GUI.Title = {
 initialise: function() {
  var elements = $$('a');

  this.show(); /* now it refers to the namespace */

  elements.each(function(element) {
   this.show(); /* this refers to the window object, not to the namespace */
  });

},
 show: function() {
  element.show();
 }
}

'this' refers to the namespace outside the each-function and inside the each it refers to the window.

Can someone explain to me how I can use 'this' in the each-loop as a referer to the namespace?

I am using Prototype.

• javascript
• prototypejs
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Share Improve this question Follow edited Dec 28, 2011 at 10:58 Rob W 349k8787 gold badges807807 silver badges682682 bronze badges asked Feb 21, 2011 at 16:37 SanderSander 1,27411 gold badge1313 silver badges2626 bronze badges

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2 Answers 2

Sorted by: Reset to default 11

Use Prototype's bind method to modify what this means inside the function.

elements.each(function(element) {
   this.show();
}.bind(this));

replace

this.show(); /* now it refers to the namespace */

elements.each(function(element) {
   this.show(); /* this refers to the window object, not to the namespace */
});

with

var scope = this;
elements.each(function(element) {
   scope.show(); /* this refers to the window object, not to the namespace */
});

what you are doing is creating a closure, the 'scope' var gets 'closed-in' to your each function lexically. Note that this approach is not prototype specific, it's a general javascript technique.