Micro-CMS: Page Content using Model Methods

This article is an enhancement to the Micro-CMS developed in these tutorials, A Micro-CMS in Rails , and Enhancements to Micro-CMS .

What we'll do is add a field to our pages that specifies a Model, Method, and Partial name, delimited by '|'. For example, if you had a model "member" for staff members, you might say "Member|get_list|members_list". The page will then display the "body" field, followed by the list of Members.

$ script/generate migration page_add_modelmethod

Edit 003_page_add_modelmethod.rb

    def self.up

      add_column :pages, :modelmethod,    :string

    end

    def self.down

      remove_column :pages, :modelmethod

    end

Then,

$ rake db:migrate 

Next, lets handle this new model attribute. Edit controllers/pages_controller.rb in def show before the responds_to:

    unless @page.modelmethod.nil?

      data_model, data_method, @data_partial = @page.modelmethod.split(/\s*\|\s*/) 

      data_method ||= 'get_list' 

      @data_partial ||= data_model.downcase.pluralize + '_list'

      @data = Object.const_get(data_model).send(data_method)

    end

And edit views/pages/show.rhtml, insert this content after the @page.body,

<div>

  <%= @page.body %>

  <% unless @data.nil? %>

    <%= render :partial => @data_partial, :object => @data %>

  <% end %>

</div>

OK. Now, a usage example. Since we already have a User model, lets just use that (rather than, say, creating a Member model for staff members as suggested in the beginning). Add to file models/user.rb

    def self.get_list

      find(:all, :order => "login")

    end

Create a partial file view/pages/_users_list.rhtml

    <table>

      <tr>

        <th>User</th>

        <th>Email</th>

        <th>Joined</th>

      </tr>

    <% for user in users_list %>

      <tr>

        <td><%=h user.login %></td>

        <td><%=h user.email %></td

        <td><%=h user.created_at %></td>

      </tr>

    <% end %>

    </table>

Create a new page named "staff", with body like "<h2>Meet our Staff</h2>", and in the "modelmethod" field add:

User|get_list|users_list

where "User" is the model name, "get_list" is the method that returns a list of users, and "users_list" is the partial (file name pages/_users_list.rhtml).

The last two parts of the field are optional, and per our code, defaults to "get_list" and {model.downcase.pluralized + '_list'}, so in this case it would be sufficient to write

User

Note, you may need to add the modelmethod field to view/pages/new.rhtml and edit.rhml as follows:

  <p>

    <b>Data Model|Method|Partial</b><br />

    <%= f.text_field :modelmethod %>

  </p>

(I welcome suggestions how to make this more Rails-way).