Mage

Mage can be used for making model creation wizards with step by step validations in Rails.

Add this line to your application's Gemfile:

gem 'mage'

And then execute:

$ bundle install

After that generate migration:

$ rails g mage

And migrate your database:

$ rake db:migrate

Define steps in your model:

class Product < ActiveRecord::Base
  has_mage_steps :name, :price, :category
end

Add validations for each step, using mage_step_STEPNAME? syntax:

  validates :name, presence: true, if: :mage_step_name?
  validates :price, presence: true, if: :mage_step_price?
  validates :category, presence: true, if: :mage_step_category?

You can use also custom validators or anything you want, just define on which step they should be run. Also bear in mind that each step runs validations of all previous steps. Step increases after successful save of the object.

After that create steps subdirectory in views directory of your controller.

$ mkdir app/views/products/steps

Put there templates for each step, naming them like steps. You can use form_for helper in your templates:

<h1>Creating new product, step 1</h1>
<%= form_for @product do |f| %>
    <%= f.label :name %>
    <%= f.text_field :name %>
    <%= f.submit %>
<% end %>

And the main part, it's time to set up your controller! Use render_mage method with your object as argument in each place that you want to render wizard. This method will render necessary template from steps directory according to the state of the object.

  def new
    @product = Product.new
    render_mage(@product)
  end

  def create
    @product = Product.new(product_params)
    @product.save
    render_mage(@product)
  end

  def edit
    @product = Product.find(params[:id])
    render_mage(@product)
  end

  def update
    @product = Product.find(params[:id])
    @product.update(product_params)
    render_mage(@product)
    redirect_to product_path(@product)
  end

Take a look at update action in our example, there's redirect_to method after render_mage. Yes, this code will be executed only if your object is finished wizard, if not - wizard will be rendered, and all the code below render_mage won't be executed, so you don't need to worry about that.

Also if tou want to show current step in url as a param, you can use show_step option each time you call render_mage method like this:

render_mage(@product, show_step: true)

To query only finished objects use 'mage_done' scope:

def index
    @products = product.mage_done
end

Bug reports and pull requests are welcome on GitHub at https://github.com/effect305/mage.

I think there's a lot of stuff to do. Here's just examples:

• Keep flash messages if showing step
• Generator
• Back button
• Tests

The gem is available as open source under the terms of the MIT License.