ajax-datatables-rails

Under new management

Hi,

New maintainer here. Just to let you know that we have released version 0.1.0 which includes breaking changes.

Please check the CHANGELOG to learn about these changes.

All changes have been documented below.

Datatables is a nifty jquery plugin that adds the ability to paginate, sort, and search your html tables. When dealing with large tables (more than a couple hundred rows) however, we run into performance issues. These can be fixed by using server-side pagination, but this breaks some datatables functionality.

ajax-datatables-rails is a wrapper around datatable's ajax methods that allow synchronization with server-side pagination in a rails app. It was inspired by this Railscast. I needed to implement a similar solution in a couple projects I was working on so I extracted it out into a gem.

ORM support

Currently AjaxDatatablesRails only supports ActiveRecord as ORM for performing database queries.

Adding support for Sequel, Mongoid and MongoMapper is a planned feature for this gem. If you'd be interested in contributing to speed development, please open an issue and get in touch.

Installation

Add these lines to your application's Gemfile:

gem 'jquery-datatables-rails'
gem 'ajax-datatables-rails'

And then execute:

$ bundle

Usage

The following examples assume that we are setting up rails-datatables for an index of users from a User model

Generate

Run the following command:

$ rails generate datatable User

This will generate a file named user_datatable.rb in app/datatables. Open the file and customize in the functions as directed by the comments.

Take a look here for an explanation about the generator syntax.

Customize

# uncomment the appropriate paginator module,
# depending on gems available in your project.
# include AjaxDatatablesRails::Extensions::Kaminari
# include AjaxDatatablesRails::Extensions::WillPaginate
# include AjaxDatatablesRails::Extensions::SimplePaginator

def sortable_columns
  # list columns inside the Array in string dot notation.
  # Example: 'users.email'
  @sortable_columns ||= []
end

def searchable_columns
  # list columns inside the Array in string dot notation.
  # Example: 'users.email'
  @searchable_columns ||= []
end

• For paginator options, just uncomment the paginator you would like to use, given the gems bundled in your project. For example, if your models are using Kaminari, uncomment AjaxDatatablesRails::Extensions::Kaminari. You may remove all commented lines.

  • SimplePaginator is the most basic of them all, it falls back to passing offset and limit at the database level (through ActiveRecord of course, as that is the only ORM supported for the time being).

• For sortable_columns, assign an array of the database columns that correspond to the columns in our view table. For example [users.f_name, users.l_name, users.bio]. This array is used for sorting by various columns.

• For searchable_columns, assign an array of the database columns that you want searchable by datatables. For example [users.f_name, users.l_name]

This gives us:

include AjaxDatatablesRails::Extensions::Kaminari

def sortable_columns
  @sortable_columns ||= ['users.f_name', 'users.l_name', 'users.bio']
end

def searchable_columns
  @searchable_columns ||= ['users.f_name', 'users.l_name']
end

Map data

def data
  records.map do |record|
    [
        # comma separated list of the values for each cell of a table row
        # example: record.attribute,
      ]
  end
end

This method builds a 2d array that is used by datatables to construct the html table. Insert the values you want on each column.

def data
  records.map do |record|
    [
      record.f_name,
      record.l_name,
      record.bio
    ]
  end
end

See here if you need to use view helpers in the returned 2d array, like link_to, mail_to, resource_path, etc.

Get Raw Records

def get_raw_records
  # insert query here
end

This is where your query goes.

def get_raw_records
  User.all
end

Obviously, you can construct your query as required for the use case the datatable is used. Example: User.active.with_recent_messages.

Controller

Set up the controller to respond to JSON

def index
  respond_to do |format|
    format.html
    format.json { render json: UserDatatable.new(view_context) }
  end
end

Don't forget to make sure the proper route has been added to config/routes.rb.

View

• Set up an html <table> with a <thead> and <tbody>
• Add in your table headers if desired
• Don't add any rows to the body of the table, datatables does this automatically
• Add a data attribute to the <table> tag with the url of the JSON feed

The resulting view may look like this:

<table id="users-table", data-source="<%= users_path(format: :json) %>">
  <thead>
    <tr>
      <th>First Name</th>
      <th>Last Name</th>
      <th>Brief Bio</th>
    </tr>
  </thead>
  <tbody>
  </tbody>
</table>

Javascript

Finally, the javascript to tie this all together. In the appropriate js.coffee file:

$ ->
  $('#users-table').dataTable
    bProcessing: true
    bServerSide: true
    sAjaxSource: $('#users-table').data('source')
    sPaginationType: 'full_numbers'
    # optional, if you want full pagination controls.
    # Check dataTables documentation to learn more about
    # available options.

or, if you're using plain javascript:

// users.js

jQuery(document).ready(function() {
  $('#users-table').dataTable({
    'bProcessing': true,
    'bServerSide': true,
    'sAjaxSource': $('#users-table').data('source'),
    'sPaginationType': 'full_numbers',
    // optional, if you want full pagination controls.
    // Check dataTables documentation to learn more about
    // available options.
  });
});

Additional Notes

Using view helpers

Sometimes you'll need to use view helper methods like link_to, h, mailto, edit_resource_path in the returned JSON representation returned by the data method.

To have these methods available to be used, this is the way to go:

class MyCustomDatatable < AjaxDatatablesRails::Base
  # either define them one-by-one
  def_delegator :@view, :link_to
  def_delegator :@view, :h
  def_delegator :@view, :mail_to
  
  # or define them in one pass
  def_delegators :@view, :link_to, :h, :mailto, :edit_resource_path, :other_method
  
  # now, you'll have these methods available to be used anywhere
  # example: mapping the 2d jsonified array returned.
  def data
    records.map do |record|
      [
        link_to(record.fname, edit_resource_path(record)),
        mail_to(record.email),
        # other attributes
      ]
    end
  end
end

Options

An AjaxDatatablesRails::Base inherited class can accept an options hash at initialization. This provides room for flexibility when required. Example:

class UnrespondedMessagesDatatable < AjaxDatatablesRails::Base
  # customized methods here
end

datatable = UnrespondedMessagesDatatable.new(view_context,
  { :foo => { :bar => Baz.new }, :from => 1.month.ago }
)

datatable.options
#=> { :foo => { :bar => #<Baz:0x007fe9cb4e0220> }, :from => 2014-04-16 19:55:28 -0700 }

Generator Syntax

Also, a class that inherits from AjaxDatatablesRails::Base is not tied to an existing model, module, constant or any type of class in your Rails app. You can pass a name to your datatable class like this:

$ rails generate datatable users
# returns a users_datatable.rb file with a UsersDatatable class

$ rails generate datatable contact_messages
# returns a contact_messages_datatable.rb file with a ContactMessagesDatatable class

$ rails generate datatable UnrespondedMessages
# returns an unresponded_messages_datatable.rb file with an UnrespondedMessagesDatatable class

In the end, it's up to the developer which model(s), scope(s), relationship(s) (or else) to employ inside the datatable class to retrieve records from the database.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request