JavaScript YUI3 using global variables?

问题

I can't work out how to update a global variable from within YUI3.

Consider the following code:

window.myVariable = 'data-one';
var yuiWrap = YUI().use('node',function(Y) {
  console.log(window.myVariable); // 'data-one'
  window.myVariable = 'data-two';
  console.log(window.myVariable); // 'data-two'
});
console.log(window.myVariable); // 'data-one'

Can anyone explain this to me? It's causing me a lot of trouble. Why can window.myVariable be accessed but not properly updated from within a YUI3 block?

I think it might have something to do with Closures but I don't understand why Closures should apply to the global "window" object.

Help?

回答1:

The callback is not fired immediately but after something happened:

Attaches one or more modules to the YUI instance. When this is executed, the requirements are analyzed, and one of several things can happen:

All requirements are available on the page -- The modules are attached to the instance. If supplied, the use callback is executed synchronously.

Modules are missing, the Get utility is not available OR the 'bootstrap' config is false -- A warning is issued about the missing modules and all available modules are attached.

Modules are missing, the Loader is not available but the Get utility is and boostrap is not false -- The loader is bootstrapped before doing the following....

Modules are missing and the Loader is available -- The loader expands the dependency tree and fetches missing modules. When the loader is finshed the callback supplied to use is executed asynchronously.

来源：https://stackoverflow.com/questions/6034275/javascript-yui3-using-global-variables

标签

javascript

yui

closures

yui3