Alex Pooley’s Blog

Social Welfare Overview

Social Welfare is a Rails plugin that makes it dead simple to update children objects from within their parent’s view. The plugin has been streamlined so that you don’t have to write much code to derive the benefits.

The problem with Rails is that it is hard to build interfaces that facilitate edits of multiple related items. Say for instance you have a shopping list and you want to modify the description of each item in the list. To do so with a scaffolded version of rails you would have to visit the edit URL of each item in the list! AJAX goes part of the way to solve this problem using in-place editing and so on, but ultimately this system falls short in situations like those that require atomic transactions.

What You Get

Social Welfare gives you the following features:

• Update a child element
• Add a new child
• Remove an existing child
• Sort the children
• Clone a child

All user updates are made to the interface only and no data is transmitted to the server until the user submits the form. The screenshot to the right is taken while updating a parent. The interface when creating a new parent is almost exactly the same (and so is the code).

How To Use Social Welfare

Here’s a very quick example of using the plugin. For full documentation check out the rdoc’s. Please note that you only need to edit parent models and views. There is no need to modify controller classes at all!

# model/todo_list
include SocialWelfare
has_many :items, :class_name => "TodoItem", :foreign_key => "todo_list_id", :subsidize => true, :order => 'sort_id'

# views/todo_list/new
<% form_for(@todo_list, :html => {:onsubmit => reorder_children(@todo_list, :items, 'sort_id')}) do |f| %>
	<%= render :partial => 'list', :locals => {:f => f} %>


    <%= f.submit "Update" %>
  

<% end %>

# views/todo_list/_list


  <b>Name</b>
  <%= f.text_field :name %>


<% subsidize(@todo_list, :items, 'order' => 'sort_id') do |children| %>
<table id="items">
<tr>
<th></th>
<th>sort id</th>
<th>description</th>
<th></th>
</tr>

	<%= children.render 'hidden_elements' => false %>
</table>

<%= children.add %>
<% end %>

# views/todo_list/_item
<tr class="<%= item.css_class %>">
<td>
		<%= item.hidden_elements %>
		<%= item.up %>
		<%= item.down %>
	</td>
<td><%= item.sort_id %></td>
<td>
<input type="text" name="<%= item.html_name('description') %>" value="<%= item.description %>" />
	</td>
<td>
		<%= item.remove %>
		<%= item.clone %>
	</td>
</tr>

<% end %>

How To Install

From the root of your rails application:

ruby script/plugin install http://dev.alexpooley.com/social_welfare/tags/1.0
rm -rf vendor/plugins/social_welfare
mv vendor/plugins/1.0 vendor/plugins/social_welfare

If you want to run the todo demo application then you will find it in the test directory of the plugin. You will need to run “rake db:migrate” to build the database. The demo assumes you have sqlite3 setup for Rails. If this is not the case, you will need to modify the database configuration of the demo application.

More Details

Find out more about the plugin on the Social Welfare page.

Tags: rails, ruby, social welfare

This entry was posted on Monday, December 17th, 2007 at 10:35 am and is filed under Technical. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.