What does $ tag mean in Appcelerator Titanium

Question

What does $ tag mean in Appcelerator? When I use this tag in any controller.js it works. But when I use it in libs js file I get error.

$.resetClass(someController, 'someClass')

Answer 1

$ tag is the holder for a controller file. It is autogenerated by Titanium for every controller file.

Let's say you have these sets of files : 1 - index.xml, index.js, index.tss 2 - win.xml, win.js, win.tss 3 - dialog.xml, dialog.js, dialog.tss

So, $ is available for every .js file & it is the same thing which is returned by this:

dialog.js

var dollar = Alloy.createController('win');
// now dollar is exactly equal to ($ in win.js) & so does for other .js files.

---

In win.xml, suppose you have a topmost Window or View with an id='topView' & some internal child views lets say having ids = view1, view2, etc...

win.xml

<Alloy>
 <View id='topView'>
   <View id='view1'>
     <View id='view2'></View>
   </View>
 </View>
</Alloy>

now in win.js file, you can access these view ids like $.topView, $.view1, $.view2 & so on like this...

---

Finally in that var dollar code, you can access these ids from any other js file just like this:

var topView = dollar.topView;
var view1 = dollar.view1;
var view2 = dollar.view2;

---

To elaborate more, suppose you want to export some functionality from a controller to any other controller, you can do it this way:

win.js

$.methodNameToAccess = function () {alert('Kerberos!')};

---

here is the magic of exporting methods

dialog.js

dollar.methodNameToAccess();    // alerts your name :)

This was the basic guide what $ is and it's beyond that.. so it's your task now to explore it & use it efficiently.

Code Strong!