Making The Leap

Rails, and therefore ruby, are always amazing me. Just today, I was working on a site that had a job object. The job belonged to both a company and a project. Now, normally, given restful routing, you have something like this as your url

http://www.mycoolsite.com/projects/1/jobs/4/edit

or

http://www.mycoolsite.com/companies/2/jobs/4/edit

and this will load up the form for a job object. In my jobs controller, I have a method as such:

class JobsController < ApplicationController
  before_filter :get_dependencies

  def get_dependencies
    #requests will come in from either projects or companies
    @project = Project.find(params[:project_id]) unless params[:project_id].nil?
    @company = Company.find(params[:company_id]) unless params[:company_id].nil?
    @parent = @project || @company
  end
end

and depending on whether the request came in from a context of a company or a project, the @parent object will contain that object. The form can also determine if the the parent object is a company or a project and pre-fill that blank with the correct information. All of this is pretty standard. The part that I was stuck on was linking to these forms. Given these urls:

http://www.mycoolsite.com/companies/2/jobs

http://www.mycoolsite.com/projects/1/jobs

How can I link to the add or edit actions without having to do something un-dry like this:

- if @parent.is_a? Project
  =link_to 'Edit', edit_project_job_path(@parent, job)
- else
  =link_to 'Edit', edit_company_job_path(@parent, job)

Well, the solution is simple, clear & concise—Would you expect anything less from RoR? :)

link_to 'Edit', edit_polymorphic_path([@parent,job])

This will automatically determine the parent object and it’s associated restful path along with the current jobs restful path.