Question

I’m new to rails and setting up the ticketee project based on Rails in Action 3, I’m attempting to deviate slightly and setup haml with views/projects/show.html.haml

I do have the Gemfile configured and haml installed and I tested a basic haml page and it does work.

Here is my problem, when migrating the show.html.erb to haml I am getting an error I can’t resolve.

show.html.erb:

<h1><%= @project.name %></h1>

This displays fine if I go to http://localhost:3000/projects/1 it displays the project name with id 1.

show.html.haml:

%h2= @project.name

After I replace show.html.erb with the haml and I go to the above url I get:

NoMethodError in Projects#show

Showing /ticketee/app/views/projects/show.html.haml
where line #1 raised:

undefined method `name' for nil:NilClass Extracted source (around line
#1):

1: %h2= @project.name Rails.root:
/ticketee

Application Trace | Framework Trace | Full Trace
app/views/projects/show.html.haml:1:in
`_app_views_projects_show_html_haml___2329513113615295829_70311891362660'

The schema.rb definitely has the name field:

ActiveRecord::Schema.define(:version => 20120212051007) do

    create_table "projects", :force => true do |t|
        t.string   "name"
        t.datetime "created_at", :null => false
        t.datetime "updated_at", :null => false
    end

end

And my controller:

class ProjectsController < ApplicationController
    def index

    end

    def new
        @project = Project.new
    end

    def create
        @project = Project.new(params[:project])
        @project.save
        #flash[:notice] = "Project has been created."
        redirect_to @project, :notice => "Project has been created."
    end

end

I assume this is just some oversight on my part as this is a very basic usage of haml.

Answer 1

It seems that you don’t have a show method inside of your Project controller. Since projects/1 means that it is a particular record, the show page would be called. When /projects is called, the index method would get called.

A possible show method could be:

  def show
    @project = Project.find(params[:id])
  end

In this method, an instance variable is assigned to @project with the ID which is in the URL. This could be the answer to your problem!