Class: ActiveAdmin::Views::IndexAsTable

Inherits:
Component
  • Object
show all
Defined in:
lib/active_admin/views/index_as_table.rb

Overview

# 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:

“‘ruby 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:

“‘ruby :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:

“‘ruby 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.

“‘ruby index do

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

end “‘

## Defining Actions

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

“‘ruby index do

selectable_column
column :title
actions

end “‘

You can also append custom links to the default links:

“‘ruby index do

selectable_column
column :title
actions do |post|
  item "Preview", admin_preview_post_path(post), class: "member_link"
end

end “‘

Or forego the default links entirely:

“‘ruby index do

column :title
actions defaults: false do |post|
  item "View", admin_post_path(post)
end

end “‘

Or append custom action with custom html via arbre:

“‘ruby index do

column :title
actions do |post|
  a "View", href: admin_post_path(post)
end

end “‘

In case you prefer to list actions links in a dropdown menu:

“‘ruby index do

selectable_column
column :title
actions dropdown: true do |post|
  item "Preview", admin_preview_post_path(post)
end

end “‘

In addition, you can insert the position of the row in the greater collection by using the index_column special command:

“‘ruby index do

selectable_column
index_column
column :title

end “‘

index_column take an optional offset parameter to allow a developer to set the starting number for the index (default is 1).

## 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.

You can pass the key specifying 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.

“‘ruby 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:

“‘ruby index do

column :title, sortable: false

end “‘

It’s also possible to sort by PostgreSQL’s hstore column key. You should set ‘sortable` option to a `column->’key’‘ value:

“‘ruby index do

column :keywords, sortable: "meta->'keywords'"

end “‘

## Custom sorting

It is also possible to use database specific expressions and options for sorting by column

“‘ruby order_by(:title) do |order_clause|

if order_clause.order == 'desc'
  [order_clause.to_sql, 'NULLS LAST'].join(' ')
else
  [order_clause.to_sql, 'NULLS FIRST'].join(' ')
end

end

index do

column :title

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:

“‘ruby controller do

def scoped_collection
  super.includes :publisher # prevents N+1 queries to your database
end

end “‘

You can also define associated objects to include outside of the ‘scoped_collection` method:

“‘ruby includes :publisher “`

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

“‘ruby 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:

“‘ruby index do

column :title, sortable: false
column :secret_data if can? :manage, Post

end “‘

## Custom row class

In order to add special class to table rows pass the proc object as a ‘:row_class` option of the `index` method.

“‘ruby index row_class: ->elem { ’active’ if elem.active? } do

# columns

end “‘

Defined Under Namespace

Classes: IndexTableFor

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.index_name ⇒ Object 



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# File 'lib/active_admin/views/index_as_table.rb', line 269

def self.index_name
  "table"
end

Instance Method Details

#build(page_presenter, collection) ⇒ Object 



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# File 'lib/active_admin/views/index_as_table.rb', line 238

def build(page_presenter, collection)
  table_options = {
    id: "index_table_#{active_admin_config.resource_name.plural}",
    sortable: true,
    class: "index_table index",
    i18n: active_admin_config.resource_class,
    paginator: page_presenter[:paginator] != false,
    row_class: page_presenter[:row_class]
  }

  table_for collection, table_options do |t|
    table_config_block = page_presenter.block || default_table
    instance_exec(t, &table_config_block)
  end
end

#default_table ⇒ Object 



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# File 'lib/active_admin/views/index_as_table.rb', line 258

def default_table
  proc do
    selectable_column
    id_column if resource_class.primary_key
    active_admin_config.resource_columns.each do |attribute|
      column attribute
    end
    actions
  end
end

#table_for(*args, &block) ⇒ Object 



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# File 'lib/active_admin/views/index_as_table.rb', line 254

def table_for(*args, &block)
  insert_tag IndexTableFor, *args, &block
end