Inject jQuery Onto Any Site

Not too long ago, one of my co-workers and I had quite an interesting problem: we needed to check every checkbox on a web form that had hundreds of checkboxes[footnote]1[/footnote]. If there had only been a few, we'd just go through and manually check each one; however, because of the sheer quantity and the time needed to actually check each box, we needed to find a faster way to get the job done.

We decided to use jQuery's excellent selecting capabilities to check all of the boxes on the current page; however, there was one major problem with this solution: jQuery was not available on the page.

After some creative thinking (and quite a bit of Googling), we came up with a solution to get jQuery on the page. We would attempt to add the library onto the page ourselves, then use it from there.

Using Chrome[footnote]2[/footnote], we opened up a console session via the web inspector and typed this:

[jscript]var element1 = document.createElement("script"); element1.src = "//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"; element1.type="text/javascript"; document.getElementsByTagName("head")[0].appendChild(element1);[/jscript]

I would recommend typing it in as one line (seems to work better that way):

[jscript]var element1 = document.createElement("script");element1.src = "//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js";element1.type="text/javascript";document.getElementsByTagName("head")[0].appendChild(element1);[/jscript]

What's happening here? Basically, we're creating a new script element via the DOM and injecting a reference to Google's hosted jQuery library into the head tag. Once that line is executed, you can access jQuery via the standard $ symbol. So, for our given situation, we just had to do this in the console:

[jscript]$(':checkbox').attr('checked', true);[/jscript]

After that, all of our checkboxes were checked! Easy enough.

[update]Per Obishawn's suggested, I've created a bookmarklet for this.[/update]

Drag this link to your bookmark bar to use on any page: Inject jQuery Onto This Page(javascript:var element1=document.createElement("script");element1.src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js";element1.type="text/javascript";document.getElementsByTagName("head")[0].appendChild(element1);)

Inspiration via: Load JavaScript after pageload.

[footnote name="1"]Why hundreds of checkboxes, you may ask. We had to mass update several products in one of our legacy systems. A large array of checkboxes was the only and easiest way to do the update.[/footnote] [footnote name="2"]Any browser that supports the WebKit Web Inspector or something similar, such as Firebug for Firefox, can do this.[/footnote]