jQuery with Rails 3
By jhuckabee on 08 February 2010
One of the most talked about features in Rails 3 is its plug & play architecture with various frameworks like Datamapper in place of ActiveRecord for the ORM or jQuery for javascript. However, I've yet to see much info on how to actually do this with the javascript framework.
Fortunately, it looks like a lot of the hard work has already been done. Rails now emits HTML that is compatible with the unobtrusive approach to javascript. Meaning, instead of seeing a delete link like this:
you'll now see it written as
This makes it very easy for a javascript driver to come along, pick out and identify the relevant pieces, and attach the appropriate handlers.
So, enough blabbing. How do you get jQuery working with Rails 3? I'll try to make this short and sweet.
Grab the jQuery driver at http://github.com/rails/jquery-ujs and put it in your javascripts directory. The file is at src/rails.js
Include jQuery (I just use the google hosted version) and the driver in your application layout or view. In HAML it would look something like.
Rails requires an authenticity token to do form posts back to the server. This helps protect your site against CSRF attacks. In order to handle this requirement the driver looks for two meta tags that must be defined in your page's head. This would look like:
In HAML this would be:
Update: Jeremy Kemper points out that the above meta tags can written out with a single call to "csrf_meta_tag".
That should be all you need. Remember, this is still a work in progress, so don't be surprised if there's a few bugs. Please also note this has been tested with Rails 3.0.0.beta.
By Jeremy Kemper (not verified) on Mon, 02/08/2010 - 23:17
You can use <%= csrf_meta_tag %> in your head to spit out those two meta tags.
By jhuckabee on Mon, 02/08/2010 - 23:24
Thanks for the tip Jeremy. Much simpler.
By CodeOfficer (not verified) on Tue, 02/09/2010 - 02:20
I just ported the build in rails javascript helpers over to jquery as well
http://www.codeofficer.com/blog/entry/jquery_helpers_for_rails_300beta/
By Armando Sosa (not verified) on Tue, 02/09/2010 - 05:11
I really like this approach, but I didn't know those attributes. Are they valid HTML?
Thanks!
(Your SPAM filter thinks I'm spam? I think that your SPAM filter is rude :( )
By Łukasz Adamczak (not verified) on Tue, 02/09/2010 - 10:47
Although much cleaner, this approach still doesn't make the link truly unobtrusive.
I mean, this link works fine for JS-enabled clients, but leads to the "show" action for users with JS disabled.
button_to (aka forms) still seems the way to go for valid post/put/delete actions. And that worked well in 2.x as well.
By jhuckabee on Tue, 02/09/2010 - 12:05
@Armando, yes, they are valid HTML 5 attributes. See http://dev.w3.org/html5/spec/Overview.html#custom
@Lukasz, good point. I would be surprised if the Rails core team hasn't thought about this and ways to address it. For now, yes, button_to seems like a good way to go if you need to support non JS-enabled clients.
By SM (not verified) on Tue, 02/09/2010 - 14:44
Good integration. Thanks
By Anonymous (not verified) on Wed, 02/10/2010 - 00:45
HTML5 and JS required?
That is a bit of a restriction isn't it? Will jrails (the Rails 2.3 jQuery drop-in replacement) still work with rails 3 so that those of us who were happy with the old method can use jQuery with rails 3 for maximum browser compatibility/accessability?
By jhuckabee on Wed, 02/10/2010 - 01:14
HTML 5 custom attributes are required by the default implementation, yes. However, given how permissive browsers are, its not something I would worry about.
Also, judging by this: http://www.w3schools.com/browsers/browsers_stats.asp I wouldn't worry about the few percentage of people who might have JS turned off.
What's nice about Rails is that its easy to tweak to your liking. For the majority of users though, the new solution is cleaner and will work just fine.
By grigio (not verified) on Wed, 02/10/2010 - 17:13
this is an example of Rails 3 UJS
http://github.com/grigio/rails3-ujs-demo
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