# Rails Serverside Datatables made easy

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'rails_serverside_datatables'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install rails_serverside_datatables

## Usage

### Basic usage

Lets say we have the following model `User`:

```
firstname | lastname | score
----------+----------+-------
Jane      | Doe      | 42
John      | Doe      | 23
...       | ...      | ...
```

To create a datatable you can sort and filter, just create a controller method like this one:

```ruby
class UsersController < ApplicationController
    include RailsServersideDatatables

    # ...
    
    def ajax
      datatable( [
        { display_name: 'Firstname', expression: :firstname },
        { display_name: 'Lastname',  expression: :lastname },
        { display_name: 'Score',     expression: :score }
      ], User.all )
    end
    
    # ...

end
```

Add the required entry to the `routes.rb`, e.g.:

`get '/users/datatable_ajax', to: 'users#ajax'`

Now you can reference you datatable by either creating the table on your own and initialize it using datatables... or you just use the following code in your view:

`<%= serverside_datatable( users_ajax_path, 'user-table', class: 'my-css-class' ) %>`

### Computed columns

Let's say you only want to show the name in the form `lastname, firstname` in one column and double the score adding 'points':

```ruby
class UsersController < ApplicationController
    include RailsServersideDatatables

    # ...
    
    def ajax
      datatable( [
        { display_name: 'Firstname', expression: [ :lastname, ' ', :firstname ] },
        { display_name: 'Score',     expression: [ text_cast( num_op( :score, '*', 2 ) ), ' points' ] }
      ], User.all )
    end
    
    # ...

end
```

### Decorator functions

If you want to display the data in a custom style, you can use structured data (e.g. additional data queried you can then use in the decorator method) and a decorator block. 

The structured data can be passed in the `config` parameter. Every key that is not a predefined parameter like `display_name` is used as an additional expression queried from the database:

```ruby
class UsersController < ApplicationController
    include RailsServersideDatatables

    # ...
    
    def ajax
      datatable( [
        Column.new( :name, [ :lastname, ' ', :firstname ], display_name: 'Full name', uid: :id ) {
          |value, data| view_context.link_to value, user_path( data[:uid] )
        },
        Column.new( :score, :score, display_name: 'Score' ) {
          |value, _| "#{value} points"
        }
      ], User.all )
    end
    
    # ...

end
```


## License

The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).