Meet Netzke::GridPanel

Here's an instance of GridPanel, which by default provides for:

Code (the helper):

netzke :bosses, 
  :class_name => "GridPanel", 
  :model => 'Boss'

Result:

Control over columns

If you need more control over which columns to display and how, you can provide :columns option:

  netzke :bosses_custom_columns, 
    :class_name => "GridPanel", 
    :model => 'Boss', 
    :ext_config => {
      :rows_per_page => 20, 
      :title => "Bosses",
      :width => 400
    },
    :columns => [:id, # id should always be included and is by default hidden
      :last_name, 
      {:name => :salary, :editable => false, :label => "$", :renderer => 'usMoney'}, 
      {:name => :email, :width => 180}]

Result:

Model-wide configuration, associations, Rails validations and "virtual" columns

Here's an example that demonstrates:

# Model
class Clerk < ActiveRecord::Base
  belongs_to :boss

  validates_presence_of :first_name
  validates_presence_of :last_name

  # result of this method will be displayed in a "virtual column"
  def name
    "#{last_name}, #{first_name}"
  end

  # this method will be used by another "virtual column"
  def updated
    updated_at > 5.minutes.ago
  end
end

# Helper that provides additional "virtual column" (keep the model clean)
module Netzke::Helpers::Clerk
  # Returns html that shows a on/off bulb
  def updated_bulb
    bulb = updated ? "on" : "off"
    "<div class='bulb-#{bulb}' />"
  end
end

# Helper that specifies which columns should be displayed, and in which configuration
module Netzke::Helpers::GridPanelClerk
  # which model's methods should be used as virtual column, along with configuration
  def self.virtual_attributes
    [:name]
  end
  
  # preconfigure some columns
  def self.attributes_config
    {
      :salary => {:renderer => "usMoney"},
      :updated_bulb => {:width => 40, :header => "<div class='bulb-off' />"},
      :name => {:renderer => "uppercase", :width => 200}
    }
  end
  
  # Which columns and in which order to expose.
  # Note the double underscore notation for signaling which (virtual) column
  # of the association should be used.
  def self.exposed_attributes
    %w{ id name first_name last_name updated_bulb email salary boss__last_name }
  end
end

# In the view:
netzke :clerks, 
  :class_name => "GridPanel", 
  :model => 'Clerk'

Result:

Permissions

netzke :bosses_with_permissions, 
  :class_name => "GridPanel", 
  :model => 'Boss', 
  :ext_config => {
    :prohibit_update => true,
    :prohibit_delete => true
  }

Result:

A word about the security: it's not only about disabling buttons. Even if the user manages to submit a prohibited operation, the server side of the widget will block the attempt.

Dynamic configuration

Real power of the Netzke framework lies in its baked-in dynamic configurability. GridPanel and FormPanel from netzke-basepack provide interface to its configuration options. In real-life application these options are automatically stored per user/role, and can be quickly changed by the administrator with the help of masquerading. GridPanel below is configured to provide access to its configuration panel (click the "gear" tool on the right top of it) - use it to change different functional and representational aspects of this GridPanel instance. Besides that, the FormPanel-based forms for creating/editing records inherit the configuration mode, hence they are also configurable. And, finally, the search form is configurable as well: you can specify which criteria for search as you wish.

Code:

netzke :configurable_clerks, :class_name => "Wrapper", :item => {
  :class_name => "GridPanel", 
  :model => 'Clerk',
  :ext_config => {
    :mode => :config, # here we enable the configuration mode
    :title => "Configurable clerks"
  }
}

We wrap the grid up so that after changing its configuration it can be automatically reloaded without the need to reload the page. Btw, this touches another powerful concept behind the Netzke framework: ability to easily nest widgets.

Result:

Get the code

Netzke framework consists of 2 Rails plugins/Ruby gems: netzke-core and netzke-basepack. Get them on the GitHub along with the source code for this demo: http://github.com/skozlov

The news about Netzke development and more tutorials on http://blog.writelesscode.com

--- The following links alter test data (the page will be reloaded):

regenerate test data

reset configs (e.g. columns configurations, permissions, etc )