cryo28 / nested_form

Rails plugin to conveniently handle multiple models in a single form.

Nested Form¶ ↑

A Rails gem to conveniently manage multiple nested models in a single form. It does so in an unobtrusive way through jQuery or Prototype.

This gem only works with Rails 3. See the rails2 branch for a plugin to work in Rails 2.

Setup¶ ↑

Add it to your Gemfile then run bundle to install it.

gem "nested_form"

Next run the generator to create the JavaScript file.

rails generate nested_form:install

Running the generator will add a file at public/javascripts/nested_form.js which should be included after the jQuery or Prototype framework.

<%= javascript_include_tag :defaults, "nested_form" %>

Usage¶ ↑

Use the nested_form_for helper method to enable the nesting.

<%= nested_form_for @project do |f| %>

Use this form just like normal, including the fields_for helper method for nesting models. The benefit of this plugin comes from the link_to_add and link_to_remove helper methods on the form builder.

<%= f.fields_for :tasks do |task_form| %>
  <%= task_form.text_field :name %>
  <%= task_form.link_to_remove "Remove this task" %>
<% end %>
<p><%= f.link_to_add "Add a task", :tasks %></p>

This generates links which dynamically add and remove fields.

Partials¶ ↑

This feature is still in development and not yet working.

It is often desirable to move the nested fields into a partial to keep things organized. If you don’t supply a block to fields_for it will look for a partial and use that.

<%= f.fields_for :tasks %>

In this case it will look for a partial called “task_fields” and pass the form builder as an f variable to it.

Special Thanks¶ ↑

This gem was originally based on the solution by Tim Riley in his complex-form-examples fork.

Thank you Andrew Manshin for the Rails 3 transition, Andrea Singh for converting to a gem and Peter Giacomo Lombardo for Prototype support.

Andrea also wrote a great blog post on the internal workings of this gem.