Can RJS render new javascript?

rubyonrails-talk
1

Hi -

I'm trying to create a widget where my rails code generates a fresh widget (which is javascript) to replace the old one. To do this, I need to insert new javascript with AJAX with RJS (so my partial begins with <script...). Is this possible? Right now, it replaces the old widget div with nothing and I get no errors. Is this a browser safeguard or something?

Thanks for any help, Dino

2

dino d. wrote:

I'm trying to create a widget where my rails code generates a fresh widget (which is javascript) to replace the old one. To do this, I need to insert new javascript with AJAX with RJS (so my partial begins with <script...). Is this possible? Right now, it replaces the old widget div with nothing and I get no errors. Is this a browser safeguard or something?

Wouldn't your controller action look like this?

   def xhr_whatever      render :update do |rjs|        rjs.replace :my_div, '<script> js blah blah blah </script>'      end    end

The stack should handle escaping, javascript-ing, escaping, transmitting, de-escaping, evaluating, and de-escaping that.

But I'm sure there's a better way to write your actual feature. I sling Ajax here and there all the time and never once found a need to push a '<script>'...

3

Thanks for the reply. I'm writing the <script> code because i'm testing an example user of the widget, and it simply calls the website that generates the widget. so is there some escaping type issue that would prevent directly rendering a <script> tag from RJS?

4

Thanks for the reply. I'm writing the <script> code because i'm testing an example user of the widget, and it simply calls the website that generates the widget. so is there some escaping type issue that would prevent directly rendering a <script> tag from RJS?

Prototype strips script tags (see Prototype API Documentation | Element.replace (Deprecated URL) )

Fred

5

Thanks Fred. I see in the code that you're correct (however that link implies that you can do this, it shows an example of how to add a script tag). So generically, is it ever possible to use an ajax call, such as link_to_remote, where response partial renders javascript?

Thanks, Dino

6

Thanks Fred. I see in the code that you're correct (however that link implies that you can do this, it shows an example of how to add a script tag). So generically, is it ever possible to use an ajax call, such as link_to_remote, where response partial renders javascript?

I suppose you could just assign stuff to element.innerHTML without using prototype. ALso prototype does actually eval the script tags, it just doesn't leave them hanging around in the DOM.

Fred

7

Sorry for the dumb follow up, but can you do that in RJS (update an elements innerHTML directly) ?

Thanks Fred, Dino

8

Sorry for the dumb follow up, but can you do that in RJS (update an elements innerHTML directly) ?

Well there's the assigns thing in RJS, failing that you can execute arbitrary javascript with <<

Fred