DatabaseViews

DatabaseViews is Rails 3.x plugin that allows you to store and load views from the database. It currently supports Monoid, but is extensible enough to support other ORMs.

Add in your Gemfile:

gem 'database_views'

Create a view template model that includes DatabaseViews::Orm::Mongoid. You can name this model whatever you like, I'll use ViewTemplate in this example.

rails g model ViewTemplate

In the model:

class ViewTemplate
  include Mongoid::Document
  include Mongoid::Timestamps
  include DatabaseViews::Orm::Mongoid
end

Here are the fields DatabaseViews::Orm::Mongoid adds:

path - The path to the view template. Excludes any file extensions (ie. "posts/index").

contents - The body of the view template.

formats (default: :html) - Format the handler renders to.

locale (default: :en) - Locale of the template.

handlers (default: :erb) - The template handler for this extension (ie. :erb, :haml).

In the your controller, you can prepend_view_path if you want your Rails to check your resolver first for the view template, or you can append_view_path, if you want it check your resolver at the end of the lookup stac.k

class ApplicationController < ActionController::Base
  append_view_path ViewTemplate.resolver
  # prepend_view_path ViewTemplate.resolver
end

DatabaseViews defines a DatabaseResolver that extends ActionView::PathResolver. A #query method is defined on this class that tells the resolver how to look up a template in the database. In the controller, prepending or appending your resolver to the view path will include it in the lookup stack when Rails looks for a view template to render.

This blog post by arailsdemo, was very helpful in understanding how view templates and resolvers worked in Rails 3. I'd also recommend Crafting Rails Applications by José Valim.