blocks|key|856982|text|也许你需要考虑有条件地加载它，而不是有条件地卸载它……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|856983|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

perhaps you need to consider conditionally loading it rather than conditionally unloading it...

blocks|key|857058|text|不，这不可能。您可以构建一个简单的清理函数来删除该文件中定义的所有变量：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|857059|var+foo+=+'bar';
var+cleanup+=+function+()+{
++++delete+window.foo;
++++delete+window.cleanup;
};

//+unload+all+resources
cleanup();|code-block|syntax|javascript|857060|另一种方法是对你的片段使用模块化的对象结构，这些片段在它们自己之后就会被清除。这涉及到稍微高一点的开销，但可能是值得的，因为它使代码更容易阅读和维护：|857061|//+creates+the+object+using+the+second+parameter+as+prototype.
//+.create()+is+used+as+constructor
GlobalModuleHandlerThingy.addModule('my_module',+{
++++create:+function+()+{
++++++++this.foo+=+'bar';
++++++++return+this;
++++},
++++foo:+null,
++++destroy:+function+()+{
++++++++//+unload+events,+etc.
++++}
});

GlobalModuleHandlerThingy.getModule('my_module').foo;+//+=>+bar
GlobalModuleHandlerThingy.unloadModule('my_module');+//+calls+.destroy()+on+the+module+and+removes+it.|857062|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

No, that is not possible. You could build a simple cleanup function that removes all variables that were defined in that file:

<pre><code>var foo = 'bar';
var cleanup = function () {
 delete window.foo;
 delete window.cleanup;
};

// unload all resources
cleanup();
</code></pre>

Another approach would be to use a modular object structure for your fragments, that clean up after themselves. That involves a slightly higher overhead but is probably worth it, as it makes the code much easier to read and maintain:

<pre><code>// creates the object using the second parameter as prototype.
// .create() is used as constructor
GlobalModuleHandlerThingy.addModule('my_module', {
 create: function () {
 this.foo = 'bar';
 return this;
 },
 foo: null,
 destroy: function () {
 // unload events, etc.
 }
});

GlobalModuleHandlerThingy.getModule('my_module').foo; // =&gt; bar
GlobalModuleHandlerThingy.unloadModule('my_module'); // calls .destroy() on the module and removes it.
</code></pre>

blocks|key|1071657|text|这是做不到的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1071658|执行脚本时，会将函数定义添加到全局window对象中。可能存在附加到函数的调试符号，这些符号指示函数的来源，但此信息对脚本不可用。|offset|length|style|CODE|1071659|要实现这样的效果，唯一的方法就是在脚本中创建一个伪命名空间，然后在完成后丢弃整个命名空间。然而，这个问题提示我，你正试图以错误的方式做一些事情。也许详细阐述您的方案将有助于我们提供替代解决方案。|1071660|entityMap^0|0|H|6|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

This cannot be done.

When a script is executed, function definitions are added to the global <code>window</code> object. There may be debugging symbols attached to the function that indicate where the function came from, but this information is not available to scripts.

About the only way you could achieve something like this would be to create a pseudo-namespace in the script and then throw away that whole namespace when you are done with it. However, this question hints to me that you are trying to do something the wrong way. Perhaps elaborating on your scenario would help us provide alternate solutions.

blocks|key|1071746|text|如果需要卸载某个特定对象，非常简单:只需将其设置为{}即可|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1071747|即：myobj+=+{};|1071748|因此，如果您知道在特定的include中创建了哪些对象，那么这一点都不难。|1071749|另一方面，如果您不知道在特定的include中创建了什么对象，就没有机制可以找出答案--您不能要求Javascript告诉您在特定的include中定义了什么。|1071750|然而，我要说的是，如果你不知道在一个特定的javascript文件中加载了什么对象，那么在加载它(你应该总是对代码在你的站点中做什么有一个合理的了解)，或者尝试手动卸载它(如果你不知道它做了什么，这意味着它是第三方包括的，这意味着手动取消它可能会破坏东西)，你可能对自己没有任何好处。|1071751|entityMap^0|P|2|0|2|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|W|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|X|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|O|$]]

If you need to unload a specific object, it's fairly easy: just set it to <code>{}</code>

ie: <code>myobj = {};</code>

So if you know what objects are created in a particular include, it won't be hard at all.

On the other hand, if you don't know what objects are created in a particular include, there isn't a mechansim to find out - you can't ask Javascript to tell you what was defined in a particular include.

However, I would say that if you don't know what objects are being loaded in a particular javascript file, you're probably not doing yourself any favours in loading it (you should always have a reasonable idea what code does in your site), or in trying to unload it manually (if you don't know what it does, that implies its a third party include, which means that unsetting it manually is likely to break things).

blocks|key|1071784|text|您可以使它们=+null|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1071785|++++function+fnc1+(){

++++}

++++window.fnc1++=+null
++++//or
++++window["fnc1"]++=+null|code-block|syntax|javascript|1071786|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

you can make them = null 

<pre><code> function fnc1 (){

 }

 window.fnc1 = null
 //or
 window["fnc1"] = null
</code></pre>

How can I unload a JavaScript resource with all its defined objects from the DOM?

Im developing a simple framework that enables to load html fragments into a "main" html. Each fragment is self contained and may include references to additional JS and CSS files. The JS and CSS resources are parsed and dynamically added to the html. When the fragment is removed/replaced from the DOM I want to remove its JS and CSS. 

If I remove the script element in the example below, the functions defined in page1.js are still available. 

<pre><code>&lt;html&gt;
 &lt;head&gt;
 &lt;script src="page1.js" type="text/javascript"&gt;&lt;/script&gt;
 &lt;/head&gt;
&lt;body&gt;
...
</code></pre>

Is there a way to unload page1.js objects from the DOM?

========= The test code I use =======

I tried the advice i got in the comments below; to delete the added objects using a cleanup function - but even this fails. The sources i used for testing:

<pre><code>&lt;html&gt;
&lt;head&gt;
&lt;script type="text/javascript"&gt;
 function loadJSFile(){
 var scriptTag = document.createElement("script");
 scriptTag.setAttribute("type", "text/javascript");
 scriptTag.setAttribute("src", "simple.js");

 var head = document.getElementsByTagName("head")[0];
 head.appendChild(scriptTag);
 }

 function unloadJSFile(){ 
 delete window.foo;
 delete window.cleanup;
 alert("cleanedup. typeof window.foo is " + (typeof window.foo));
 }
&lt;/script&gt;
&lt;/head&gt;
&lt;body&gt;

 Hello JavaScript Delete

 &lt;br/&gt;
 &lt;button onclick="loadJSFile();"&gt;Click to load JS&lt;/button&gt;
 &lt;br/&gt;
 &lt;button onclick="foo();"&gt;call foo()&lt;/button&gt;
 &lt;br/&gt;
 &lt;button onclick="unloadJSFile();"&gt;Click to unload JS&lt;/button&gt;

&lt;/body&gt;
&lt;/html&gt;
</code></pre>

simple.js source:

<pre><code>var foo = function(){
 alert("hello from foo");
}
</code></pre>

How to unload a javascript from an html?

如何从DOM中卸载包含所有已定义对象的JavaScript资源？我正在开发一个简单的框架，可以将html片段加载到一个“主”html中。每个片段都是自包含的，并且可以包含对其他JS和CSS文件的引用。JS和CSS资源被解析并动态地添加到html。当从DOM中删除/替换该片段时，我希望删除它的JS和CSS。如果我删除下面...

问如何从html中卸载javascript？
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