/todolists3

Assignment for Module #3: ActionPack

Primary LanguageRuby

Assignment for Module #3: ActionPack

The overall goal of this assignment is to assess your ability to implement and customize Rails scaffold.

This includes:

  • Creating a Rails scaffold for a Model, View, and Controller (MVC)
  • Modifying the runtime application flow
  • Re-using and customizing partial views
  • Sharing state through the controller attributes with the view
  • Implementing an end-to-end display of a custom query result

The functional goal of this assignment is to implement a web application to manage TodoItems.

Functional Requirements

  1. Create the scaffold for the following model type:

    • TodoItem

  2. Create the Database (DB) schema for TodoItem

  3. Change the default scaffolding to route to the index page versus the show page after a TodoItem is created

  4. Remove the Edit link from the index view.

  5. Modify the TodoItem view partial to display the Completed property when a TodoItem is being edited and not during creation.

  6. Display the number of completed TodoItems.

Getting Started

  1. Create a new Rails application called todolists

  2. Add the following specification to your Gemfile

    group :test do
  gem 'rspec-rails', '~> 3.0'
  gem 'capybara'
end

  3. Run the bundle command to resolve new gems

  4. From the todolists application root directory, initialize the rspec tests using the rails generate rspec:install command

      [todolists]$ rails generate rspec:install
      create  .rspec
      create  spec
      create  spec/spec_helper.rb
      create  spec/rails_helper.rb

    Add the following line to .rspec to add verbose output to test results.

    --format documentation

  5. Download and extract the starter set of bootstrap files.

    |-- Gemfile
|-- db
|    `-- seed.rb
`-- spec
    `-- features
        `-- module3_action_pack_spec.rb

    • overwrite your existing Gemfile with the Gemfile from the bootstrap fileset. They should be nearly identical, but this is done to make sure the gems and versions you use in your solution can be processed by the automated Grader when you submit. Any submission should be tested with this version of the file.

    • overwrite your existing db/seed.rb file using the seeds.rb provided with the bootstrap fileset. The bootstrap seeds.rb file contains some test data that will be useful during development and unit tests.

    • add the spec/features/module3_action_pack_spec.rb file provided with the bootstrap fileset to your todolists application. Within your application root directory, you will first need to create a corresponding spec/features sub-directory to place the module3_action_pack_spec.rb file. This file contains tests that will help determine whether you have completed the assignment.

  6. Run the rspec test(s) to receive feedback. rspec must be run from the root directory of your application. All tests will (obviously) fail until you complete the specified solution.

    $ rspec 
...
19 examples, 1 failure, 17 pending

    To focus test feedback on a specific step of the requirements, add "-e rq##" to the rspec command line to only evaluate that requirement. Pad all step numbers to two digits.

    $ rspec -e rq01
Run options: include {:full_description=>/rq01/}

Module #3
  rq01
    Generate Rails application
      must have top level structure of a rails application

Finished in 0.00465 seconds (files took 1.56 seconds to load)
1 example, 0 failures

  7. Implement your solution to the technical requirements and use the rspec tests to help verify your completed solution.

  8. Submit your Rails app solution for grading.

Technical Requirements

  1. Create a new Rails app called todolists. Use the Gemfile provided in the bootstrap files (as stated in Step 5 within the Getting Started section). Do not change this Gemfile from what is provided or your submitted solution may not be able to be processed by the grader (i.e., do not add any additional gems or change gem versions).

    $ rails new ...
$ rspec -e rq01

  2. Using the rails generate scaffold command, create a Rails MVC artifact for a TodoItem that has the following business-related fields:

    • TodoItem
      • due_date - date when the specific task is to be complete
      • title - a string with short name for specific task
      • description - a string with narrative text for specific task
      • completed - a boolean value (default=false), indicating whether item is complete

    It is assumed that this type will also contain the id, created_at, and updated_at fields. Migrate the database as a part of this requirement to populate the database with the TodoItem schema.

    $ rails g scaffold ... 
$ rake db:migrate 
$ rspec -e rq02

    Note that the above rake db:migrate command will execute against the db/development.sqlite3 database instance. The capybara rspec tests will use the db/test.sqlite3 database instance and automatically run db:migrate and db:seed on its own. The default database for all commands is the development database.

    • Use rake db:seed RAILS_ENV=test to execute the db/seed.rb against the test database.
    • Use rails db -e test to access the test database.
    • Use rails c test to use the Rails console to interact with the test database.

    Since the grader uses a separate test database instance, you can modify the state of the development database as you wish during your development.

    We will have specific interest in the following artifacts.

    db/migrate/..._create_todo_items.rb
app/models/todo_item.rb
app/controllers/todo_items_controller.rb
app/views/todo_items/index.html.erb
app/views/todo_items/edit.html.erb
app/views/todo_items/show.html.erb
app/views/todo_items/new.html.erb
app/views/todo_items/_form.html.erb

  3. Seed the database with the db/seeds.rb file supplied in the student-start bootstrap files. Do not modify this file. The grader expects test results to be based on this input.

    $ rake db:seed 
$ rspec -e rq03

  4. Start the Rails server and navigate to the todo_items index page.

    $ rails s

    http://localhost:3000/todo_items

    $ rspec -e rq04

  5. Using the New Todo item link, create a new TodoItem (with any data). After a new Todo Item has been successfully created, notice the page that it navigated you to. This is the show page.

    $ rspec -e rq05

    • Review how the submit action in the view invokes a create URI when the user presses the Create Todo Item button.

      app/views/todo_items/new.html.erb
app/views/todo_items/_form.html.erb
      <%= form_for(@todo_item) do |f| %>
  ...
  <div class="actions">
    <%= f.submit %>
  </div>
<%= end %>

    • Notice that the create method in the controller handles the create URI call passed by the view and persists the new TodoItem. When the save operation is completed, the controller then redirects the flow to the show URI for the @todo_item.

      # POST /todo_items
# POST /todo_items.json
def create
  @todo_item = TodoItem.new(todo_item_params)

  respond_to do |format|
    if @todo_item.save
      format.html { redirect_to @todo_item, notice: 'Todo item was successfully created.' }
      format.json { render :show, status: :created, location: @todo_item }
    ...
    end
  end
end

    • Notice that the show method in the controller retrieves the persisted TodoItem by :id. By default the flow continues to the show page, where the view displays the details of the newly created @todo_item.

      class TodoItemsController < ApplicationController 
  before_action :set_todo_item, only: [:show, ...] 

... 

# GET /todo_items/1
# GET /todo_items/1.json
def show
end 

...

private
    # Use callbacks to share common setup or constraints between actions.
    def set_todo_item
      @todo_item = TodoItem.find(params[:id])
    end

    ...
      app/views/todo_items/show.html.erb
      <p>
  <strong>Due date:</strong>
  <%= @todo_item.due_date %>
</p>

<p>
  <strong>Title:</strong>
  <%= @todo_item.title %>
</p>

<p>
  <strong>Description:</strong>
  <%= @todo_item.description %>
</p>

<p>
  <strong>Completed:</strong>
  <%= @todo_item.completed %>
</p>

    • Note the mapping of helper_method_prefix, method/URI, and controller#method mappings shown by the rake routes command. This shows which action in the controller will be called when a method/URI is invoked.

      • The controller method is optional and the flow will continue to the view of the same name as the intended action when that occurs.
      • If a controller method does exist and matches the action's name, it has the ability to add member @variables with state for the views to use (e.g., set_todo_item called prior to show).
      • If the controller method does not change the route (e.g., show does not change the route), then the flow will continue to the view of the same name as the action.
      • If the controller method changes the route through a redirect_to (e.g., the create action re-directs the flow to the show URI), the flow will follow the newly defined path by sending the HTTP client a re-direct.
      • If the controller method changes the route using a render (e.g., the create action redenders a JSON document response when JSON is requested), the specified view is returned directly to the client.
      $ rake routes
        Prefix Verb   URI Pattern                    Controller#Action
    todo_items GET    /todo_items(.:format)          todo_items#index
               POST   /todo_items(.:format)          todo_items#create
 new_todo_item GET    /todo_items/new(.:format)      todo_items#new
edit_todo_item GET    /todo_items/:id/edit(.:format) todo_items#edit
     todo_item GET    /todo_items/:id(.:format)      todo_items#show
               PATCH  /todo_items/:id(.:format)      todo_items#update
               PUT    /todo_items/:id(.:format)      todo_items#update
               DELETE /todo_items/:id(.:format)      todo_items#destroy

  6. Modify the flow so that the user is directed back to the index page after creating a TodoItem instead of the show page. (Hint: you are changing the URI redirected by the controller's create method. Use rake routes to help determine the appropriate helper_method_prefix, URI, and controller#method mappings. Append _url to the helper method prefix when implementing this redirection.)

    $ rake routes
$ rspec -e rq06

  7. Remove the Edit link from the index page view. (You will still be able to access edit from the show page view).

    $ rspec -e rq07

  8. Add conditional logic to the _form.html.erb partial so that it only displays the completed property when editing and not when creating. (A TodoItem cannot possibly be done before it is created;)

    $ rspec -e rq08

    Hint: You can obtain the model object's persisted state using object.persisted? or object.new_record? to help determine if it is new or being edited.

  9. Display the number of completed TodoItems on the index page.

    1. Implement a class method in the TodoItem model that returns the count of completed TodoItems.
    2. Update the index method in the controller class to assign the count of completed TodoItems in a member variable (.e.g, @number_of_completed_todos)
    3. Display the count of completed TodoItems on the index page using a reference by the view -- to the member variable defined in the controller class. The grader is looking for the result to be expressed as Number of Completed Todos: # anywhere on the page -- where # is the number of completed todos. There must be a single space between the : and number.
    $ rspec -e rq09

    Hint: This should be very similar to how the view class gets the list of TodoItems from the controller using the @todo_items member variable.

Self Grading/Feedback

Some unit tests have been provided in the bootstrap files and provide examples of tests the grader will be evaluating for when you submit your solution. They must be run from the project root directory.

$ rspec 
...
19 examples, 0 failures

You can run as many specific tests you wish be adding -e rq## -e rq##

$ rspec -e rq01 -e rq02

Submission

Submit an .zip archive (other archive forms not currently supported) with your solution root directory as the top-level (e.g., your Gemfile and sibling files must be in the root of the archive and not in a sub-folder. The grader will replace the spec files with fresh copies and will perform a test with different query terms.

|-- app
|   |-- assets
|   |-- controllers
|   |-- helpers
|   |-- mailers
|   |-- models
|   `-- views
|-- bin
|-- config
|-- config.ru
|-- db
|-- Gemfile
|-- Gemfile.lock
|-- lib
|-- log
|-- public
|-- Rakefile
|-- README.rdoc
|-- test
`-- vendor

Last Updated: 2015-10-25