Documentation : Customizing the Index Page : Index as a Table

By default, the index page is a table with each of the models content columns and links to show, edit and delete the object. There are many ways to customize what gets displayed.

Defining Columns

To display an attribute or a method on a resource, simply pass a symbol into the column method:

  index do
    column :title
  end

For association columns we make an educated guess on what to display by calling the following methods in the following order:

  :display_name, :full_name, :name, :username, :login, :title, :email, :to_s

This can be customized in config/initializers/active_admin.rb.

If the default title does not work for you, pass it as the first argument:

  index do
    column "My Custom Title", :title
  end

Sometimes that just isn’t enough and you need to write some view-specific code. For example, say we wanted a “Title” column that links to the posts admin screen.

column accepts a block that will be rendered for each of the objects in the collection. The block is called once for each resource, which is passed as an argument to the block.

  index do
    column "Title" do |post|
      link_to post.title, admin_post_path(post)
    end
  end

To setup links to View, Edit and Delete a resource, use the actions method:

  index do
    column :title
    actions
  end

You can also append custom links to the default links:

  index do
    column :title
    actions do |post|
      link_to "Preview", admin_preview_post_path(post), :class => "member_link"
    end
  end

Or forego the default links entirely:

  index do
    column :title
    actions :defaults => false do |post|
      link_to "View", admin_post_path(post)
    end
  end

Sorting

When a column is generated from an Active Record attribute, the table is sortable by default. If you are creating a custom column, you may need to give Active Admin a hint for how to sort the table.

If a column is defined using a block, you must pass the key to turn on sorting. The key is the attribute which gets used to sort objects using Active Record.

  index do
    column "Title", :sortable => :title do |post|
      link_to post.title, admin_post_path(post)
    end
  end

You can turn off sorting on any column by passing false:

  index do
    column :title, :sortable => false
  end

Associated Sorting

You’re normally able to sort columns alphabetically, but by default you can’t sort by associated objects. Though with a few simple changes, you can.

Assuming you’re on the Books index page, and Book has_one Publisher:

  controller do
    def scoped_collection
      resource_class.includes(:publisher) # prevents N+1 queries to your database
    end
  end

Then it’s simple to sort by any Publisher attribute from within the index table:

  index do
    column :publisher, sortable: 'publishers.name'
  end

Showing and Hiding Columns

The entire index block is rendered within the context of the view, so you can easily do things that show or hide columns based on the current context.

For example, if you were using CanCan:

  index do
    column :title, :sortable => false
    if can? :manage, Post
      column :some_secret_data
    end
  end
Copyright 2011 Greg Bell and VersaPay