:format: :textile
:title: Unobtrusive JS 0.2.2 – “the two in one day!” release
:published_on: Thu Aug 10 17:55:00 UTC 2006
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I’m sure many people are aware of the risks in running pre-1.0 software/plugins and that there are likely to be many bugs discovered until that 1.0 release finally hits (and beyond).

Unfortunately, it takes really working with a Rails plugin to find problems and I have been doing so today. I encountered a strange error where the plugin was generating IDs for elements that shouldn’t have any javascript events attached.

Update 21/08/2006: The latest version of this plugin is 0.3 – please see [this post](http://www.lukeredpath.co.uk/2006/8/21/ujs-rails-plugin-0-3-new-name-new-website) and the [official UJS website](http://www.ujs4rails.com) for more information.

def tag_options(opts)
  unless opts[:inline]
    JAVASCRIPT_EVENTS.each do |event|
      if opts.include?("on#{event}") # this was the culprit!
        opts['id'] = generate_html_id unless opts['id']
        register_js_behaviour("##{opts['id']}:#{event}",
                  opts["on#{event}"]) unless opts["on#{event}"].nil?
        opts.delete("on#{event}")
      end
    end
  end
  rails_tag_options(opts)
end

What it turned out that was happening was that some Rails helpers were adding empty onclick handlers to some tags so they were being picked up by the above code. All that was required was a simple fix:

# get rid of this
# if opts.include?("on#{event}") 
# and use this:
unless opts["on#{event}"].blank?

So [grab Unobtrusive Javascript for Rails 0.2.2](http://opensource.agileevolved.com/svn/root/rails_plugins/unobtrusive_javascript/tags/rel-0.2.2/) while its hot!