Retrieving the source code of JavaScript script
I've been doing some scraping and at some websites I found references to JS like this:
<script type="text/javascript">
unescape("%3Cscript src='Scriptdir/pr.asp?id=123456' language='javascript'%3E%3C/script%3E"));
</script>
In such cases, it is triv开发者_运维技巧ial to retrieve the script code (just go to the link). But how do I retrieve the code in cases like this:
<select ID="Spinner" class="text" onchange="javascript:IWantTheCodeOfThis();">
Is it even possible, or are they stored server-side without an acces for the client?
JavaScript is always stored server-side but executed client-side, so the browser has to get hold of it at some time (unlike to e.g. PHP-code).
What you posted is a JS-function-call so the function "IWantTheCodeOfThis" must be in one of the include-files which are "trivial to retrieve" :)
You could use Chrome or Safari to use the console and look at the resources. You could also type IWantTheCodeOfThis
(without ()) in the console, and you will probably see the source code for the function.
Not at all. Any access to Javascript has to be on the client already.
To lookup where the function is located, it's a good idea to use a debugger like Firebug
or the Chrome developer tools
. Both explicitly show you all available javascript sources on the current site.
JavaScript is executed on the client side. Always.
IWantTheCodeOfThis() is a function that would be in one of the JavaScript downloaded by the browser. Most of the new browsers has some time of "inspector", "develop menu", or "developer tools" from which you can see all of the scripts that were loaded and even search them. Safari, Chrome and Internet Explorer 8/9 all have this. In Firefox, you can use Firebug.
You could go through the scripts by hand but that would be difficult as some websites may load some of their JavaScripts dynamically.
精彩评论