Challenge 1: Write a Full Controller — Solution

class CommentsController < ApplicationController
  # No render call here -- Rails implicitly renders
  # app/views/comments/index.html.erb after this action finishes.
  def index
    @comments = Comment.all
  end

  # No render call here either -- implicitly renders
  # app/views/comments/show.html.erb.
  def show
    @comment = Comment.find(params[:id])
  end

  def new
    @comment = Comment.new
  end

  def create
    @comment = Comment.new(comment_params)
    if @comment.save
      redirect_to @comment
    else
      render :new
    end
  end

  def edit
    @comment = Comment.find(params[:id])
  end

  def update
    @comment = Comment.find(params[:id])
    if @comment.update(comment_params)
      redirect_to @comment
    else
      render :edit
    end
  end

  def destroy
    Comment.find(params[:id]).destroy
    redirect_to comments_path
  end
end

=begin
Notes:
- index and show both leave their view rendering entirely to Rails'
  implicit-render convention: because neither action calls render or
  redirect_to, Rails automatically renders the view whose filename matches
  the action name, inside app/views/comments/.
- create and update both follow the same pattern: attempt to save, and
  branch based on success — redirect_to on success (a fresh request to a
  new URL), render :new or render :edit on failure (redisplaying the same
  form with whatever validation errors exist, once Chapter 7 covers
  validations in depth).
- destroy has no view of its own at all — it performs the deletion, then
  always redirects, since there's nothing meaningful left to render for a
  resource that no longer exists.
=end