Customizing admin_data for a Rails 3 application

Customizing admin_data for Rails 3 application#

admin_data allows you to configure certain features. Create a file under config/initializers named admin_data.rb such the full path to the file is config/initializers/admin_data.rb . This is the file were all the configure settings will be stored. Configuration options are listed below.

Number of records per page##

By default admin_data leaves it upto will_paginate to decided how many records should be shown in a page. You can control how many records should be shown on a page.

AdminData.config do |config|
  config.number_of_records_per_page = 50
}

##Customize column header name in the list##

By default admin_data puts the column name as the column header in the search result. Here is how you can configure that

AdminData.config do |config|
  config.column_headers = {'City' => {:id => 'ID', :name => 'City Name', :data => 'City Info'}}
end

##Add additional column to display extra information##

Let's say I have a User model which has_many Phone_numbers. In the search list I also want to see all the phone number of the given user. This is how that can be accomplished.

config.columns_order = { 'User' => [:id, :phone_numbers]) }
config.column_settings = {'User' => { :phone_numbers => lambda { |model| 
                      model.phone_numbers.map {|r| r.number}.join(', ') } } }

First line is saying that in the columns_order phone_numbers will come after id. The second line is saying how to calculate the value for that column.

Override the default find condition

I have a model called City which is defined like this.

class City < ActiveRecord::Base
  def to_param
    self.permanent_name
  end
end

For show action admin_data will generate url which could look like /admin_data/city/miami .

The controller will execute the query assuming that id is miami and the record will not be found.

Here is how that can be fixed.

AdminData.config do |config|
  config.find_conditions =  {'City' => lambda {|params| {:conditions =>   ["permanent_name = ?", params[:id] ] } } }  
}

Override the default behaviour of a column##

I have a Car model.

class Car < ActiveRecord::Base
  serialize :data
end

I am creating a new car record.

Car.create(:data => { :color => ‘black’, :year => ‘2000’})

If you look at this record using admin_data then for the column ‘data’ will have following value:

colorblackyear2000

This is not very useful. If I could ask plugin to perform inspect on hash then output will be much more easy to read. Given below is how I can ask plugin to perform inspect method on data column.

AdminData.config do |config|
  config.column_settings = { 'Car' => { :data => lambda{|model| model.data.inspect}}}
})

admin_data passes the model instanct to proc and the user can customize the value for that model as per his/her taste.

Replace drop down associations with input text

Let’s say that I have two tables: users table and phone_numbers. If I edit a phone number then I would be presented with the drop down of all the user ids. If I have 50 thousand user records then page will be really slow .

To get around this problem you can configure admin_data so that instead of select field you are given input text.

AdminData.config do |config|
 config.drop_down_for_associations = false
})

Custom order of columns in listing

I have an Article model which ,by default, lists columns in following order: id, body, title, author_name, published_at .

If I want order of columns to be changed then I need configure like this.

AdminData.config do |config|
  config.columns_order = { 'Article' => [:id, :title, :body, :published_at, :author_name] }  
}

##Explicitly defining route to get around catch-all issue##

I have defined a catch-all route so that users can have twitter like url http://twitter.com/user_name . I have defined catch-all route as given below.

get ':username' => 'users#show'

Now when I try to go to http://localhost:3000/admin_data, I am directed to users controller. How do I get around to this issue.

To get around this issue explictly define the admin_data routes like this

match '/admin_data', :to => 'admin_data/home#index'

If you find this conflicts with the item view path (/admin_data/klass/:class/:id) then rename the helper like this

match '/admin_data', :to => 'admin_data/home#index', :as => 'admin_data_root'