worker importScripts

http://stackoverflow.com/questions/14500091/uncaught-referenceerror-importscripts-is-not-defined

http://www.html5rocks.com/en/tutorials/workers/basics/#toc-gettingstarted

 

Importing scripts and libraries

Worker threads have access to a global function, importScripts() , which lets them import scripts or libraries into their scope.  It accepts as parameters zero or more URIs to resources to import; all of the following examples are valid:

importScripts();                        /* imports nothing */
importScripts('foo.js');                /* imports just "foo.js" */
importScripts('foo.js', 'bar.js');      /* imports two scripts */

 

传入 Worker 构造函数的参数 URI 必须遵循 同源策略。

The browser loads each listed script and executes it. Any global objects from each script may then be used by the worker. If the script can't be loaded,NETWORK_ERROR is thrown, and subsequent code will not be executed. Previously executed code (including code deferred using window.setTimeout()) will still be functional though. Function declarations after the importScripts() method are also kept, since these are always evaluated before the rest of the code.

Note: Scripts may be downloaded in any order, but will be executed in the order in which you pass the filenames into importScripts() .  This is done synchronously; importScripts() does not return until all the scripts have been loaded and executed.

 

Web Workers and the DOM

Since web workers are in external files, they do not have access to the following JavaScript objects:

• The window object
• The document object
• The parent object

 

Uncaught ReferenceError: importScripts is not defined

Why do I keep getting this error?

I should be able to use this global function right?

http://www.html5rocks.com/en/tutorials/workers/basics/

I'm using chrome.

I'm using https://code.google.com/p/bitjs/ and it begins with

importScripts('io.js');
importScripts('archive.js');　　 //importScripts API只能在worker中使用，  archive.js文件中不能再使用importScripts,并且archive.js文件中不能使用 1.

• The window object 2.

• The document object 3.

• The parent object

This code needs to be inside a worker script. The worker itself is created via a new Worker object - seeGetting Started in the tutorial.

The code you've linked is inside the worker created here.

 

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Features Available to Workers

Due to their multi-threaded behavior, web workers only has access to a subset of JavaScript's features:

• The navigator object
• The location object (read-only)
• XMLHttpRequest
• setTimeout()/clearTimeout() andsetInterval()/clearInterval()
• The Application Cache
• Importing external scripts using the importScripts() method
• Spawning other web workers

Workers do NOT have access to:

• The DOM (it's not thread-safe)
• The window object
• The document object
• The parent object