# Effective DataTables

Uniquely powerful server-side searching, sorting and filtering of any ActiveRecord or Array collection as well as post-rendered content displayed as a frontend jQuery Datatable.

Use a simple DSL in just one ruby file to implement all features

Search raw database tables and ruby post-rendered results at the same time

Packages the jQuery DataTables assets for use in a Rails 3.2.x & Rails 4.x application using Twitter Bootstrap 2 or 3

## Getting Started

```ruby
gem 'effective_datatables'
```

Run the bundle command to install it:

```console
bundle install
```

Install the configuration file:

```console
rails generate effective_datatables:install
```

The generator will install an initializer which describes all configuration options.


Require the javascript on the asset pipeline by adding the following to your application.js:

```ruby
# For use with Bootstrap3 (which is not included in this gem):
//= require effective_datatables

# For use with Bootstrap2 (which is not includled in this gem):
//= require effective_datatables.bootstrap2
```

Require the stylesheet on the asset pipeline by adding the following to your application.css:

```ruby
# For use with Bootstrap3 (which is not included in this gem):
*= require effective_datatables

# For use with Bootstrap2 (which is not not included in this gem):
*= require effective_datatables.bootstrap2
```

## Usage

We create a model, initialize it within our controller, then render it from a view

### The Model

Start by creating a model in the `/app/models/effective/datatables/` directory.

Any `Effective::Datatable` models that exist in this directory will be automatically detected and 'just work'.

Below is a very simple example file, which we will expand upon later.

This model exists at `/app/models/effective/datatables/posts.rb`:

```ruby
module Effective
  module Datatables
    class Posts < Effective::Datatable
      table_column :id
      table_column :user    # if Post belongs_to :user
      table_column :title
      table_column :created_at

      def collection
        Post.all
      end

    end
  end
end
```

### The Controller

We're going to display this DataTable on the posts#index action

```ruby
class PostsController < ApplicationController
  def index
    @datatable = Effective::Datatables::Posts.new()
  end
end
```

### The View

Here we just render the datatable:

```erb
<h1>All Posts</h1>

<% if @datatable.collection.length == 0 %>
  <p>There are no posts.</p>
<% else %>
  <%= render_datatable(@datatable) %>
<% end %>
```

## How It Works

When the jQuery DataTable is first initialized on the front-end, it makes an AJAX request back to the server asking for data.

The effective_datatables gem intercepts this request and returns the appropriate results.

Whenever a search, sort, filter or pagination is initiated on the front end, that request is interpretted by the server and the appropriate results returned.

Due to the unique search/filter ability of this gem, a mix of raw database tables and processed results may be worked with at the same time.


### Effective::Datatable Model & DSL

Once your controller and view are set up to render a Datatable, the model is the central point to configure all behaviour.

This single model file contains just 1 required method and responds to only 3 DSL commands.

Each `Effective::Datatable` model must be defined in the `/app/models/effective/datatables/` directory.

For example: `/app/models/effective/datatables/posts.rb`:

```ruby
module Effective
  module Datatables
    class Posts < Effective::Datatable
      default_order :created_at, :desc

      table_column :id, :visible => false

      table_column :created_at, :width => '25%'

      table_column :updated_at, :proc => Proc.new { |post| nicetime(post.updated_at) } # just a standard helper as defined in helpers/application_helper.rb

      table_column :user

      table_column :post_category_id, :filter => {:type => :select, :values => Proc.new { PostCategory.all } } do |post|
        post.post_category.name.titleize
      end

      array_column :comments do |post|
        content_tag(:ul) do
          post.comments.where(:archived => false).map do |comment|
            content_tag(:li, comment.title)
          end.join('').html_safe
        end
      end

      table_column :title, :label => 'Post Title', :class => 'col-title'
      table_column :actions, :sortable => false, :filter => false, :partial => '/posts/actions'

      def collection
        Post.where(:archived => false).includes(:post_category)
      end

    end
  end
end
```

### The collection

A required method `def collection` must be defined to return the base ActiveRecord collection.

It can be as simple or as complex as you'd like:

```ruby
def collection
  Posts.all
end
```

or (complex example):

```ruby
def collection
  collection = Effective::Order.unscoped.purchased
    .joins(:user)
    .joins(:order_items)
    .group('users.email')
    .group('orders.id')
    .select('users.email AS email')
    .select('orders.*')
    .select("#{query_total} AS total")
    .select("string_agg(order_items.title, '!!OI!!') AS order_items")

  if attributes[:user_id].present?
    collection.where(:user_id => attributes[:user_id])
  else
    collection
  end
end

def query_total
  "SUM((order_items.price * order_items.quantity) + (CASE order_items.tax_exempt WHEN true THEN 0 ELSE ((order_items.price * order_items.quantity) * order_items.tax_rate) END))"
end
```

## table_column

This is the main DSL method that you will interact with.

table_column defines a 1:1 mapping between a SQL database table column and a frontend jQuery Datatables table column.  It creates a column.

Options may be passed to specify the display, search, sort and filter behaviour for that column.

When the given name of the table_column matches an ActiveRecord attribute, the options are set intelligently based on the underlying datatype.

```ruby
# The name of the table column as per the Database
# This column is detected as an Integer, therefore it is :type => :integer
# Any SQL used to search this field will take the form of "id = ?"
table_column :id

# As per our 'complex' example above, using the .select('customers.stripe_customer_id AS stripe_customer_id') syntax to create a faux database table
# This column is detected as a String, therefore it is :type => :string
# Any SQL used to search this field will take the form of "customers.stripe_customer_id ILIKE %?%"
table_column :stripe_customer_id, :column => 'customers.stripe_customer_id'

# The name of the table column as per the Database
# This column is detected as a DateTime, therefore it is :type => :datetime
# Any SQL used to search this field will take the form of
# "to_char(#{column} AT TIME ZONE 'GMT', 'YYYY-MM-DD HH24:MI') ILIKE '%?%'"
table_column :created_at

# If the name of the table column matches a belongs_to in our collection's main class
# This column will be detected as a belongs_to and some predefined filters will be set up
# So declaring the following
table_column :user

# Will have the same behaviour as declaring
table_column :user_id, :if => Proc.new { attributes[:user_id].blank? }, :filter => {:type => :select, :values => Proc.new { User.all.map { |user| [user.id, user.to_s] }.sort { |x, y| x[1] <=> y[1] } } } do |post|
  post.user.to_s
end
```

All table_columns are `:visible => true`, `:sortable => true` by default.

### General Options

The following options control the general behaviour of the column:

```ruby
:column => 'users.id'     # Set this if you're doing something tricky with the database.  Used internally for .order() and .where() clauses
:type => :string          # Derived from the ActiveRecord attribute default datatype.  Controls searching behaviour.  Valid options include :string, :text, :datetime, :integer, :boolean, :year
:if => Proc.new { attributes[:user_id].blank? }  # Excludes this table_column entirely if false. See "Initialize with attributes" section of this README below
```

### Display Options

The following options control the display behaviour of the column:

```ruby
:label => 'Nice Label'    # Override the default column header label
:sortable => true|false   # Allow sorting of this column.  Otherwise the up/down arrows on the frontend will be disabled.
:visible => true|false    # Hide this column at startup.  Column visbility can be changed on the frontend.  By default, hidden column filter terms are ignored.
:width => '100%'|'100px'  # Set the width of this column.  Can be set on one, all or some of the columns.  If using percentages, should never add upto more than 100%
:class => 'col-example'   # Adds an html class to the column's TH and all TD elements.  Add more than one class with 'example col-example something'
```

### Filtering Options

Setting a filter will create an appropriate text/number/select input in the header row of the column.

The following options control the filtering behaviour of the column:

```ruby
table_column :created_at, :filter => false    # Disable filtering on this column entirely
table_column :created_at, :filter => {...}    # Enable filtering with these options

:filter => {:type => :number}
:filter => {:type => :text}

:filter => {:type => :select, :values => ['One', 'Two'], :selected => 'Two'}
:filter => {:type => :select, :values => [*2010..(Time.zone.now.year+6)]}
:filter => {:type => :select, :values => Proc.new { PostCategory.all } }
:filter => {:type => :select, :values => Proc.new { User.all.order(:email).map { |obj| [obj.id, obj.email] } } }
```

Some additional, lesser used options include:

```ruby
:filter => {:when_hidden => true}  # By default a hidden column's search filter will be ignored, unless this is true.  Can be used for scoping.
:filter => {:fuzzy => true} # Will use an ILIKE/includes rather than = when filtering.  Use this for selects.
```

### Rendering Options

There are a few different ways to render each column's output.

Any standard view helpers like `link_to` or `simple_format` and any custom helpers available to your views will be available.

All of the following rendering options can be used interchangeably:

Block format (really, this is your cleanest option):

```ruby
table_column :created_at do |post|
  if post.created_at > (Time.zone.now-1.year)
    link_to('this year', post_path(post))
  else
    link_to(post.created_at.strftime("%Y-%m-%d %H:%M:%S"), post_path(post))
  end
end
```

Proc format:

```ruby
table_column :created_at, :proc => Proc.new { |post| link_to(post.created_at, post_path(post)) }
```

Partial format:

```ruby
table_column :actions, :partial => '/posts/actions'  # render this partial for each row of the table
```

then in your `/app/views/posts/_actions.html.erb` file:

```erb
<p><%= link_to('View', post_path(post)) %></p>
<p><%= link_to('Edit', edit_post_path(post)) %></p>
```

The local object name will either match the database table singular name `post`, the name of the partial `actions`, or `obj` unless overridden with:

```ruby
table_column :actions, :partial => '/posts/actions', :partial_local => 'the_post'
```

There are also a built in helper, `datatables_admin_path?` to considering if the current screen is in the `/admin` namespace:

```ruby
table_column :created_at do |post|
  if datatables_admin_path?
    link_to admin_posts_path(post)
  else
    link_to posts_path(post)
  end
end
```

The request object is available to the table_column, so you could just as easily call:

```ruby
request.referer.include?('/admin/')
```


## table_columns

Quickly create multiple table_columns all with default options:

```ruby
table_columns :id, :created_at, :updated_at, :category, :title
```

## array_column

`array_column` accepts the same options as `table_column` and behaves identically on the frontend.

The difference occurs with sorting and filtering:

With a `table_column`, the frontend sends some search terms to the server, the raw database table is searched & sorted using standard ActiveRecord .where(), the appropriate rows returned, and then each row is rendered as per the rendering options.

With an `array_column`, the front end sends some search terms to the server, all rows are returned and rendered, and then the rendered output is searched & sorted.

This allows the output of an `array_column` to be anything complex that cannot be easily computed from the database.

When searching & sorting with a mix of table_columns and array_columns, all the table_columns are processed first so the most work is put on the database, the least on rails.


## default_order

Sort the table by this field and direction on start up

```ruby
default_order :created_at, :asc|:desc
```

## Additional Functionality

There are a few other ways to customize the behaviour of effective_datatables

### Customize Filter Behaviour

This gem does its best to provide "just works" filtering of both raw SQL (table_column) and processed results (array_column) out-of-the-box.

It's also very easy to override the filter behaviour on a per-column basis.

Keep in mind, columns that are hidden will not be considered by the filter results unless `:filter => {:when_hidden => true}` is passed to table_column

For custom filter behaviour, specify a `def search_column` method in the datatables model file:

```ruby
def collection
  User.unscoped.uniq
    .joins('LEFT JOIN customers ON customers.user_id = users.id')
    .select('users.*')
    .select('customers.stripe_customer_id AS stripe_customer_id')
    .includes(:addresses)
end

def search_column(collection, table_column, search_term)
  if table_column[:name] == 'subscription_types'
    collection.where('subscriptions.stripe_plan_id ILIKE ?', "%#{search_term}%")
  else
    super
  end
end
```

### Initialize with attributes

Any attributes passed to `.new()` will be persisted through the lifecycle of the datatable.

You can use this to scope the datatable collection or create even more advanced search behaviour.

In the following example we will hide the User column and scope the collection to a specific user.

In your controller:

```ruby
class PostsController < ApplicationController
  def index
    @datatable = Effective::Datatables::Posts.new(:user_id => current_user.try(:id))
  end
end
```

Scope the query to the passed user in in your collection method:

```ruby
def collection
  if attributes[:user_id]
    Post.where(:user_id => attributes[:user_id])
  else
    Post.all
  end
end
```

and remove the table_column when a user_id is present:

```ruby
table_column :user_id, :if => Proc.new { attributes[:user_id].blank? } do |post|
  post.user.email
end
```

## Array Backed collection

Don't want to use ActiveRecord? Not a problem.

Define your collection as an Array of Arrays, declare only array_columns, and everything works as expected.

```ruby
module Effective
  module Datatables
    class ArrayBackedDataTable < Effective::Datatable
      array_column :id
      array_column :first_name
      array_column :last_name
      array_column :email

      def collection
        [
          [1, 'Matthew', 'Riemer', 'matthew@agilestyle.com'],
          [2, 'Dallas', 'Meidinger', 'dallas@agilestyle.com'],
          [3, 'Warren', 'Uhrich', 'warren@agilestyle.com'],
          [4, 'Stephen', 'Brown', 'stephen@agilestyle.com'],
          [5, 'Dana', 'Janssen', 'dana@agilestyle.com'],
          [6, 'Ashley', 'Janssen', 'ashley@agilestyle.com'],
        ]
      end

    end
  end
end
```

## Get access to the raw results

After all the searching, sorting and rendering of final results is complete, the server sends back an Array of Arrays to the front end jQuery DataTable

The finalize method provides a hook to process the final collection as an Array of Arrays just before it is convered to JSON.

This final collection is available after searching, sorting and pagination.

As you have full control over the table_column presentation, I can't think of any reason you would actually need or want this:

```ruby
def finalize(collection)
  collection.each do |row|
    row.each do |column|
      column.gsub!('horse', 'force') if column.kind_of?(String)
    end
  end
end
```

## Authorization

All authorization checks are handled via the config.authorization_method found in the `config/initializers/effective_datatables.rb` file.

It is intended for flow through to CanCan or Pundit, but neither of those gems are required.

This method is called by the controller action with the appropriate action and resource

Action will be `:index`

The resource will be the collection base class, such as `Post`.  This can be overridden:

```ruby
def collection_class
  NotPost
end
```

The authorization method is defined in the initializer file:

```ruby
# As a Proc (with CanCan)
config.authorization_method = Proc.new { |controller, action, resource| authorize!(action, resource) }
```

```ruby
# As a Custom Method
config.authorization_method = :my_authorization_method
```

and then in your application_controller.rb:

```ruby
def my_authorization_method(action, resource)
  current_user.is?(:admin) || EffectivePunditPolicy.new(current_user, resource).send('#{action}?')
end
```

or disabled entirely:

```ruby
config.authorization_method = false
```

If the method or proc returns false (user is not authorized) an `Effective::AccessDenied` exception will be raised

You can rescue from this exception by adding the following to your application_controller.rb:

```ruby
rescue_from Effective::AccessDenied do |exception|
  respond_to do |format|
    format.html { render 'static_pages/access_denied', :status => 403 }
    format.any { render :text => 'Access Denied', :status => 403 }
  end
end
```


## License

MIT License.  Copyright [Code and Effect Inc.](http://www.codeandeffect.com/)

Code and Effect is the product arm of [AgileStyle](http://www.agilestyle.com/), an Edmonton-based shop that specializes in building custom web applications with Ruby on Rails.


## Testing

The test suite for this gem is unfortunately not yet complete.

Run tests by:

```ruby
rake spec
```

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Bonus points for test coverage
6. Create new Pull Request