Accessing DOM node information via RJS

rubyonrails-talk
1

Vishal Abru wrote:

I have been pulling my hair out for way too long on this...and it seems so trivial! The following does not work:

if page['test'].className == "whatever"   page['test'].className = "whatever2" end

Now that I write this post, I realize why it doesn't work - className is a value in the Javascript code - not in Rails. But, is there any way to access the className value in the IF statement?

Yeah, there's a fundamental misunderstanding going on here. When you write an RJS template, you're not writing Ruby that communicates 'live' with Javascript on the web browser. The entire RJS template is converted to Javascript on the server, and is then sent in one big lump to the web browser, where it is run.

Therefore, you cannot do anything in RJS that involves 'reading' something about the state of the browser or document. Or in other words, the entire RJS template has to make sense without any knowledge of what's going on in the browser/document.

I'd just drop into Javascript for this kind of thing.

Chris

2

Yet, there is a solution. I had the very same problems and have written a simple plugin that allows something like this:

page.if page['test'].hasClassName('whatever') do   page['test'].classNames.set('whatever') end

You can install it with this command:   ./script/plugin install svn://rubyforge.org/var/svn/js-if-blocks/trunk/js-if-blocks