Linker

A wrapper to form objects in ActiveRecord. Forget accepts_nested_attributes_for.

Installation

Add this line to your application's Gemfile:

gem 'linker'

And then execute:

$ bundle

Or install it yourself as:

$ gem install linker

Supported versions

• Ruby 2.0+
• Rails 3.1+ (including 4.x)

Usage

Given the below model:

class User < ActiveRecord::Base
  belongs_to :company
  belongs_to :family

  has_one :address, dependent: :destroy

  has_many :dependent_users, dependent: :destroy
  has_many :tasks, dependent: :destroy
end

Create a form class through rails g form whatever or manually (it should include Linker and have main model set like below).

class UserForm
  include Linker

  main_model User # or :user or 'User'
end

Now you can create a new form for existing user UserForm.new(User.find params[:id]) or to a new one UserForm.new(User.new):

class UsersController < ApplicationController
  def new
    @user_form = UserForm.new(User.new)
  end

  def create
    @user_form.params = users_form_params

    if @user_form.save
      redirect_to users_path, notice: 'User created successfully'
    else
      render :new
    end
  end
end

By default, save method will perform validations, you can disable them by passing validate: false as parameter.

Finally, you can use fields_for in order to display associated fields.

<%= form_for @user_form do |f| %>
  <%= f.text_field :name %>

  <%= f.fields_for :tasks do |ta| %>
    <%= ta.hidden_field :id %>
    <%= ta.text_field :name %>

  <%= f.fields_for :company do |co| %>
    <%= co.hidden_field :id %>
    <%= co.text_field :name %>
    <%= co.text_field :website %>
<% end %>

How it works

Linker will map all has_one, has_many and belongs_to associations from main model and let it ready to use.

Internally, it will include ActiveModel::Model if on Rails 4 or ActiveModel::Validations if on Rails < 4.

It will also create params= and save methods responsible to set new objects and save them. You can override these methods to get a custom behavior without worrying with delegations.

You can check out a demo project using Linker gem here. Click here to see it live.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

License

This projected is licensed under the terms of the MIT license.