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.
To display an attribute or a method on a resource, simply pass a symbol into the column method:
index do selectable_column 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
If the default title does not work for you, pass it as the first argument:
index do selectable_column 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 selectable_column column "Title" do |post| post.title, admin_post_path(post) end end
To setup links to View, Edit and Delete a resource, use the
index do selectable_column column :title actions end
You can also append custom links to the default links:
index do selectable_column column :title actions do |post| "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| "View", admin_post_path(post) end end
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.
By default, this is the column on the resource's table that the attribute corresponds to. Otherwise, any attribute that the resource collection responds to can be used.
index do column :title, sortable: :title do |post| 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
It's also possible to sort by PostgreSQL's hstore column key. You should set
option to a
index do column :keywords, sortable: "meta->'keywords'" end
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 super.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 column :secret_data if can? :manage, Post end