Accessing a URL Param Project.find(params[:project_id]) in the application_helper.rb

Question

Hello,

I'm trying to build a helper called

def current_project
    @current_project = Project.find(params[:project_id])
end

I want this so that in the navigation plugin I'm using I can use current_project to populate the navigation.

Problem I'm having is while params[:project_id] is available in the navigation config (navigation.rb) it is not working in the application_helper.rb. I get the following error:

"find_with_ids': Couldn't find Project without an ID"

Here's the navigation plugin, in case you're curious: http://github.com/andi/simple-navigation/

ideas why?

Thanks

Answer 1

Instead of

def current_project
    @current_project = Project.find(params[:project_id])
end

Try

def current_project( project_id )
        @current_project = Project.find( project_id )
end

When invoking the helper, pass the params[:project_id] for project_id param value.

Answer 2

If passing in the project_id to the helper it not an option, you can put the method into the controller and mark it as a helper_method. For example:

class ApplicationController < ActionController::Base
  helper_method :current_project

  private
    def current_project
      @current_project ||= Project.find(params[:project_id])
    end
end

Then in your views you can call it with:

<% current_project %>

as you expect.

Answer 3

Definitely agree with rjk, you should put it in application controller, because if you don't your controllers can't access the method. The issue you're getting seems to be due to a nil id (e.g. params[:project_id] isn't passed through in every request) presumably it's only passed in the navigation action which switches between projects?

I'm not sure what the internals of simple navigation do, but if params[:project_id] is only passed in the navigation action, then the navigation action should be storing this in the session session[:project_id] = params[:project_id].to_i, then you would define a private controller method + helper as follows, using the session stored id so you can access it in other actions:

class ApplicationController < ActionController::Base
  helper_method :current_project

  private
    def current_project
      @current_project ||= Project.find(session[:project_id])
    end
end