Giant Japanese Robot

Ruby on Rails: String to Object

In my new app I have a whole bunch of nested models. For the most part they all have the same database structure and can use very similar partials. I hate to repeat code because it usually makes my life more difficult when I need to go back and change something or do maintenance. I am now placing these partials in a single location that all of these models have access to.

Problem is I had a very difficult time telling the partials what object it needed to represent without adding a parameter. (I am making a lot of AJAX calls) I solved it by using the controller that was passed along with the request. After that I needed to take that string that was passed and transform it so ruby recognized it as an object. This was my final solution:

Classify takes the string and gives it the proper camelcase format so that it conforms to the model naming convention. Constantize then takes that string and converts it into an actual object.

Ruby on Rails: String to Boolean

Really, this should be simpler. Knowing Rails folks there is probably some deep philosophical reason this isn’t included, but I hold no grudge.

So….I’m converting objects back and forth to JSON and when they return all my pretty Booleans are converted into strings. My assumption was that there was a handy little .to_b(ool) method for String, but alas there does not appear to be. This is the method I ended up writing.

As always I am open to suggestions and improvements.

Ruby on Rails: Single Table Inheritance and Restful Routes

I am writing this out of a bit of frustration. I have a solution here, but it took too long and it can not be correct. I am hoping some smarter folks will chime in with some thoughts.

I have a model called Questions which has many subtypes using single table inheritance. Basically types of questions dropdown, checkbox, radio, etc etc.

These are set up as resources so I can use restful routing. I also want to use all of the rails form magic so I set up resources like this…

 map.resources :question_checkboxes, :as => :questions, :controller => :questions

This allowed the form_for method to render the form correctly and point to the “question” url instead of the url of one of the subtypes.

The next problem was that the “update” controller method was looking for very specific params “params[:question]”, but the rendered form was passing params like “params[:question_checkbox]”. The way I eventually solved this was set up a before filter and method in the controller like this…

 before_filter :form_symbol

   def form_symbol
      if params[:question] then @form_symbol = :question end
      if params[:question_checkbox] then @form_symbol = :question_checkbox end
   end

and then in the update method of the questions_controller…

 @question.update_attributes(params[@form_symbol])

It does the trick, but feels very uncomfortable. Suggestions and comments are welcome.

has_many :through & Acts_As_List

Following post is for Ruby on Rails geeks.

I don’t normally post my programming adventures here, but maybe I should. This is a simple thing and should have been obvious right away to me, but it wasn’t so I am posting it here for future generations. Thanks to Geek Mama for shaming me into posting this.

I have a “has_many :choices, :through => :question_items” model set up for Questions and their Choices. The QuestionItems model also has a”position” column because it is an Acts_As_List model. All is fine and good until I try and get the choices to return in the correct order by calling @questions.choices in my controller.

The solution was pretty simple, adding an :order option to the has_many method solved it:

has_many :choices, :through => :question_items, :order => "question_items.position"