Simple CRUD With Rails Checklist!!!

• Create project: rails new project_name
• Create table/model: rails g model Model_name_singular attribute:datatype --no-test-framework (or rails g resources Model_name_singular attribute:datatype --no-test-framework for tables, models, views, and routes)
• Run migrations
• Create relationships in model
• Check objects/relationships in console rails c
• Seed DB (optional)
• Draw routes with resources: routes, remove unnecessary routes for simplicity
• Check routes with rake:routes
• Run server rails s (refresh any time you make changes to routes)
• Create controllers (name plural), inherit from ApplicationController
• Make show pages in views, under their respective model names (plural)
• Create controller actions for CRUD/other routes as necessary (see below)
• Add validations to models

CRUD Controller Actions With Validations

  def index
    @posts = Post.all
  end

 def show
    @post = Post.find(params[:id])
  end

  def new
    @post = Post.new    # required for form_for
  end

 def create
    @post = Post.new(post_params)
    if @post.save       # same as checking if post.valid? first
      redirect_to post_path(@post)
    else
      render :new
    end
  end

  def edit
    @post = Post.find(params[:id])
  end

  def update
    @post = Post.find(params[:id])
    if @post.update(post_params)
      redirect_to post_path(@post)
    else
      render :edit
    end
  end

  def destroy
    @post = Post.find(params[:id]).destroy
    redirect_to posts_path
  end

  private

  def post_params    # strong params method, required for form_for
    params.require(:post).permit(:title, :description)
  end

Troubleshooting #destroy

• Check that your assets > javascript > application.js has the following code: //= require jquery //= require jquery_ujs

• Check that gem 'jquery-rails' and gem 'jquery-ui-rails' are in your gemfile. Run bundle install.

• Check that layouts/application.html.erb contains:

<%= stylesheet_link_tag    'application', media: 'all' %>
<%= javascript_include_tag :application %>
<%= csrf_meta_tags %>

Basic Error Messages for Validations

Printing out a list of error messages at the top of a page:

<% if @song.errors.any? %>
<div id="error_explanation">
  <h2>There were some errors:</h2>
  <ul>
    <% @song.errors.full_messages.each do |message| %>
      <li><%= message %></li>
    <% end %>
  </ul>
</div>
<% end %>

Example form field to highlight erroneous field:

<div class="field<%= ' field_with_errors' if @song.errors[:title].any? %>">
  <%= f.label :title %>
  <%= f.text_field :title %>
</div>

Associating Models with Basic Forms - Custom Setter

Character Info: <br/>
<%= form_for @character do |f| %>
  <%= f.label :name %>
  <%= f.text_field :name %> <br />
Show Info: <br/>
  <%= f.fields_for :make_show do |j| %>
    <%= j.label :title %>
    <%= j.text_field :title %><br />
  <% end %>
  <%= f.submit %>
<% end %>

# in the characters controller

def create
  @character = Character.new(character_params)
  # the association will be made once you receive hydrated object back from #make_show= and call save in the create method
end

private

def character_params
  params.require(:character).permit(:name,make_show:[:title])
end

# In the Character model

def make_show=(arg)
  build_show(args)  #OR shows.build (based on relationship)
  # show is not created, but an instance is created and associated with the character
  # object is passed back to the controller, which will call #save and persist it

end

Associating Models with Basic Forms - accepts_nested_attributes_for

# In the Recipe model

has_many :ingredients
accepts_nested_attributes_for :ingredients

# in the recipe controller

def new
  # creating 2 recipe ingredient instances here makes the form create two different ingredient objects associated with this recipe
  # we build recipe.ingredients because a recipe has_many ingredients
  @recipe = Recipe.new
  @recipe.ingredients.build
  @recipe.ingredients.build
end

def create
  @recipe = Recipe.new(recipe_params)
  # recipe_params will nest automatically and look like:
  # "recipe"=>{"title"=>"tacos", "ingredients_attributes"=>{"0"=>{"name"=>"beans","quantity"=>"1"},
  # "1"=>{"name"=>"rice", "quantity"=>"2"}}}, "commit"=>"Create Recipe"}
  @recipe.save!
  redirect_to recipe_path(@recipe)
end

private

def recipe_params
  params.require(:recipe).permit(:title, ingredients_attributes:[:name, :quantity])
end

<%= form_for @recipe do |f| %>
  <%= f.label :title %>
  <%= f.text_field :title %> <br/>
  <%= f.fields_for :ingredients do |ing| %>
    <%= ing.label :name %>
    <%= ing.text_field :name %> </br>
    <%= ing.label :quantity %>
    <%= ing.text_field :quantity %> </br>
  <% end %>
  <%= f.submit %>
<% end %>