'document' undefined in Greasemonkey

Question

Not more than ten minutes ago, I decided to write my first script for Greasemonkey. I have no experience with him. Also, my JavaScript is a bit rusty, as it has been a while since I last wrote the code. But I can not understand why Greasemonkey gives me this error:

Line: 9 Char: 2 Error: 'document' is undefined Code: 800A1391 Source: Microsoft JScript runtime error 

Here is my script:

 // ==UserScript== // @name Easier WatchSeries // @namespace n/a // @include http://www.watch-series.com/episode/* // ==/UserScript== function thing() { document.body.setAttribute('onload', show_links(document.getElementById('idepisod').value)); } thing(); 

All I want to do is add the onLoad attribute to the body tag. I get this error when I go to "Manage new user scripts" → "Edit". In addition, the script does nothing, obviously something is wrong.

I am running Firefox 3.6.13.

Answer 1

A few things:

• This cryptic error message was detected when Greasemonkey does not have a proper editor .

  • Open about: config in your browser.
  • Greasemonkey.editor filter
  • Enter a valid path to a valid editor. I like TextPad , but c:\Windows\System32\notepad.exe should work on most Windows systems.
  • You may need to restart Firefox.
    
    

• Event listeners cannot be added this way due to the Greasemonkey sandbox / security. See GM misses, event handlers .

• You need to use unsafeWindow to call JS page functions , for example show_links() .

• When using complex ajax functions that often fail, it is recommended that you wrap them in try - catch blocks.

• This page switches between www.watch-series.com and watch-series.com, so both must be in @include directives.

Combining all this, your script will become:

 // ==UserScript== // @name Easier WatchSeries // @namespace n/a // @include http://www.watch-series.com/episode/* // @include http://watch-series.com/episode/* // ==/UserScript== function my_func() { try { unsafeWindow.show_links(document.getElementById('idepisod').value); } catch (zError) { alert (zError); //-- Use console.log() in place of alert(), if running Firebug. } } window.addEventListener ("load", my_func, false);