Calling external javascript function through url bar

I want to use javascript in the url bar to manipulate the rendered html of a given page. Please note that I'm not trying to do something illegal here. Long story short, my university generates a weekly schedule based on your courses. I'd like to use javascript to add a button on the generated schedule page that will allow you to push the schedule to a google calendar. Unfortunately, I can't just go and edit the source itself (obviously), so I figured I would use javascript to edit the page once it has been rendered by my browser. I'm having some trouble calling an external javascript file to parse the rendered html.

As it is, this is what I have:

javascript:{{var e=document.createElement('script');
e.src = http://www.url.of/external/js/file.js';
e.type='text/javascript';
document.getElementsByTagName('head')[0].appendChild(e);}
functionToCall(document.body.innerHTML);}

Which, when pasted into the URL bar, SHOULD add my javascript file to the head and then call my function. Any help would be greatly appreciated, thanks!

EDIT: Here's a working example if you're interested, thanks everyone!

javascript:(function(){var e=document.createElement('script');
开发者_C百科e.src = 'http://www.somewebsite.net/file.js';
e.type='text/javascript';e.onload =function(){functiontocall();};
document.getElementsByTagName('head')[0].appendChild(e);})();

If you need the code to execute once it is loaded you can do one of two things:

1. Execute functionToCall(document.body.innerHTML); at the bottom of your script (http://www.url.of/external/js/file.js) rather than at the end of your bookmarklet.

2. Use e.onload = function(){ functionToCall(document.body.innerHTML); }; after e.type='text/javascript' near the end of your JavaScript snippet / bookmarklet, rather than calling functionToCall right after appending e to the document head (since e will most likely not have been loaded and parsed right after appendChild(e) is called.

I see that you've accepted an answer, and that's perfectly valid and great, but I would like to provide a useful tool I made for myself.

It's a bookmarklet generator called zbooks.
_{(Yes it's my website, no I'm not trying to spam you, there are no ads on that page, I gain nothing from you using it)}

It's jQuery enabled and I think it's simple to use (but I built it, so who knows). If you need an extensive explanation of how to use it, let me know so I can make it better. You can even browse over the source if you'd like.

The important part is the business logic that gets jQuery on the page:

//s used for the Script element
    var s = document.createElement('script');
    //r used for the Ready state
    var r = false;
    //set the script to the latest version of jQuery
    s.setAttribute('src', 'http://code.jquery.com/jquery-latest.min.js');
    //set the load/readystate events
    s.onload = s.onreadystatechange = function()
    {
/**
 * LOAD/READYSTATE LOGIC
 * execute if the script hasn't been ready yet and:
 * - the ready state isn't set
 * - the ready state is complete
 *   - note: readyState == 'loaded' executes before the script gets called so
 *     we skip this event because it wouldn't have loaded the init event yet.
 */
      if ( !r && (!this.readyState || this.readyState == 'complete' ) )
      {
        //set the ready flag to true to keep the event from initializing again
        r = true;
        //prevent jQuery conflicts by placing jQuery in the zbooks object
        window.zbooks = {'jQuery':jQuery.noConflict()};
        //make a new zbook
        window.zbooks[n] = new zbooks(c);
      }
    };
    //append the jQuery script to the body
    b.appendChild(s);

Can't you use a proper tool like Greasemonkey?