brenothales/select2_helper

Install

Gemfile

gem 'select2_helper', github: 'tonytonyjan/select2_helper'

application.js

//= require select2
//= require select2_helper

Usage

Let project has many tasks.

project.rb

class Project < ActiveRecord::Base
  include Select2Concern
  select2_white_list :name
  has_many :tasks
end

task.rb

class Task < ActiveRecord::Base
  include Select2Concern
  select2_white_list :status
  belongs_to :project
end

Single Select

<%=
  text_field_tag :single_demo, nil,
    class: 'select2-single',
    data: {
      model: :Project,
      column: :name
    }
%>

Multiple Select

<%=
  text_field_tag :multiple_demo, nil,
    class: 'select2-multiple',
    data: {
      model: :Project,
      column: :name
    }
%>

Nested Select

<%=
  text_field_tag :level_1, nil,
    class: 'select2-single',
    data: {
      model: :Project,
      column: :name,
      child_field: '#level_2'
    }
%>

<%=
  text_field_tag :level_2, nil,
    data: {
      model: :Task,
      column: :status,
      foreign_key: :project_id
    }
%>

Simple Form Compatiable

In application.css

/*
= require select2_simple_form_compatible
*/