Question

I have a Rails 3.2 app where a user clicks an image to select it. Clicking the image triggers an ajax POST request to a controller with an action that updates a boolean on the photo’s record to select it. It works perfectly on my local machine with Pow. However, this breaks with a 404 error on our hosting, Heroku. The record does not get updated. I’ve tried countless changes to the ajax request content types and even changed the ajax request url to suffix .html to force a request for a content type I know exists but to no avail.

I’ve used the web inspector to analyse the requests and they’re completely identical. I’m stumped.

I have the following controller:

class InstagramPhotosController < ApplicationController

  before_filter :authenticate_user!
  before_filter :set_account
  prepend_view_path('app/views/plugins')

  respond_to :html

  def add
    @account.plugin.instagram_photos.find(params[:id]).update_attribute('selected', true)
    render :nothing => true
  end

  def remove
    @account.plugin.instagram_photos.find(params[:id]).update_attribute('selected', false)
    render :nothing => true
  end

  private

  def set_account
    @account = current_user.accounts.find_by_subdomain(params[:account])
  end
end

The following javascript:

handle_change_display = function(e) {
  $('#items').show().on('click', '.instagram-image', function(e){
    if ($(this).hasClass('selected')) {
      $.publish("/remove_item", [ this ]);
    } else {
      $.publish("/add_item", [ this ]);
    }
  });
}

handle_add_item = function(e, image) {
  $.post('instagram/photos/add.html', {
      id: $(image).attr('data-photo-id')
    },
    function() {
      $(image).addClass('selected');
    }
  );
}

And these routes:

scope :account, :path => '/:account/plugins' do
  post 'instagram/photos/add'    => 'plugins/instagram_photos#add',    :as => 'instagram_photos_add'
  post 'instagram/photos/remove' => 'plugins/instagram_photos#remove', :as => 'instagram_photos_remove'
end

Rake routes gives:

instagram_photos_add POST   /:account/plugins/instagram/photos/add(.:format)        plugins/instagram_photos#add
instagram_photos_remove POST   /:account/plugins/instagram/photos/remove(.:format)     plugins/instagram_photos#remove

Thanks!

UPDATE:

Heroku’s logs are showing the following:

2012-06-19T04:10:16+00:00 app[web.1]: Started POST "/tim/plugins/instagram/photos/add.html" for 75.158.30.18 at 2012-06-19 04:10:16 +0000
2012-06-19T04:10:16+00:00 app[web.1]: 
2012-06-19T04:10:16+00:00 app[web.1]: ActionController::RoutingError (uninitialized constant Plugins::InstagramPhotosController):
2012-06-19T04:10:16+00:00 app[web.1]:   vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.2/lib/active_support/inflector/methods.rb:229:in `block in constantize'
2012-06-19T04:10:16+00:00 app[web.1]:   vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.2/lib/active_support/inflector/methods.rb:228:in `each'
2012-06-19T04:10:16+00:00 app[web.1]:   vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.2/lib/active_support/inflector/methods.rb:228:in `constantize'
snipped....

Answer 1

Ok, found it. The add route is pointing at plugins/instagram_photos#add but the controller is class InstagramPhotosController < ApplicationController i.e. NOT extending a base controller called Plugins::BaseController. No idea why this worked just fine in development.

It pays to look at the logs, kids.