Controller Actions in Ruby

From the Ruby on Rails cheat sheet · Controllers · verified Jul 2026

Controller Actions

Common controller patterns and responses

ruby

class PostsController < ApplicationController
  def index
    @posts = Post.all
    render json: @posts
  end

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

  def create
    @post = Post.new(post_params)
    if @post.save
      redirect_to @post, notice: 'Created!'
    else
      render :new, status: :unprocessable_entity
    end
  end
end

✅ Use before_action for common setup code

💡 Strong parameters required for mass assignment

🔍 respond_to handles multiple formats

⚡ Use includes() to avoid N+1 queries

controllersactionscrud

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