Module: DataMapper::Is::Published

Defined in:
lib/dm-is-published/is/published.rb,
lib/dm-is-published/is/version.rb

Overview

dm-is-published

This plugin makes it very easy to add different states to your models, like ‘draft’ vs ‘live’. By default it also adds validations of the field value.

Originally inspired by the Rails plugin acts_as_publishable by fr.ivolo.us.

Installation

#  Add GitHub to your RubyGems sources 
$  gem sources -a http://gems.github.com

$  (sudo)? gem install kematzy-dm-is-published

NB! Depends upon the whole DataMapper suite being installed, and has ONLY been tested with DM 0.10.0 (next branch).

Getting Started

First of all, for a better understanding of this gem, make sure you study the ‘dm-is-published/spec/integration/published_spec.rb’ file.

Require dm-is-published in your app.

require 'dm-core'         # must be required first
require 'dm-is-published'

Lets say we have an Article class, and each Article can have a current state, ie: whether it’s Live, Draft or an Obituary awaiting the death of someone famous (real or rumored)

class Article
  include DataMapper::Resource
  property :id,     Serial
  property :title,   String
  ...<snip>

  is :published

end

Once you have your Article model we can create our Articles just as normal

Article.create(:title => 'Example 1')

The instance of Article.get(1) now has the following things for free:

  • a :publish_status attribute with the value 'live'. Default choices are [ :live, :draft, :hidden ].

  • :is_live?, :is_draft? or :is_hidden? methods that returns true/false based upon the state.

  • :save_as_live, :save_as_draft or :save_as_hidden converts the instance to the state and saves it.

  • :publishable? method that returns true for models where is :published has been declared, but false for those where it has not been declared.

The Article class also gets a bit of new functionality:

Article.all(:draft)  =>  finds all Articles with :publish_status = :draft

Article.all(:draft, :author => @author_joe )  =>  finds all Articles with :publish_status = :draft and author == Joe
Todo

add more documentation here…

Usage Scenarios

In a Blog/Publishing scenario you could use it like this:

class Article 
  ...<snip>...

  is :published :live, :draft, :hidden
end

Whereas in another scenario - like in a MenuItem model for a Restaurant - you could use it like this:

class MenuItem
  ...<snip>...

  is :published  :on, :off  # the item is either on the menu or not
end

RTFM

As I said above, for a better understanding of this gem/plugin, make sure you study the ‘dm-is-published/spec/integration/published_spec.rb’ file.

Errors / Bugs

If something is not behaving intuitively, it is a bug, and should be reported. Report it here: github.com/kematzy/dm-is-published/issues

Credits

Copyright © 2008-05-07 [Kematzy at gmail]

Loosely based on the ActsAsPublishable plugin by [fr.ivolo.us/posts/acts-as-publishable]

Licence

Released under the MIT license.

Defined Under Namespace

Modules: ClassMethods, InstanceMethods, ResourceInstanceMethods

Constant Summary collapse

VERSION = 
'0.0.3'

Instance Method Summary collapse

Instance Method Details

#is_published(*args) ⇒ Object

method that adds a basic published status attribute to your model

params

  • states - an array of ‘states’ as symbols or strings. ie: :live, :draft, :hidden

Examples

is :published :on, :off

is :published %w(a b c d)



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# File 'lib/dm-is-published/is/published.rb', line 132

def is_published(*args)
  # set default args if none passed in
  args = [:live, :draft, :hidden] if args.blank?
  args = args.first if args.first.is_a?(Array)
  
  # the various publish states accepted.
  @publish_states = args.collect{ |state| state.to_s.downcase.to_sym }
  @publish_states_for_validation = args.collect{ |state| state.to_s.downcase }
  
  extend  DataMapper::Is::Published::ClassMethods
  include DataMapper::Is::Published::InstanceMethods
  
  # do we have a :publish_status declared
  if properties.any?{ |p| p.name == :publish_status }
    
    # set default value to first value in declaration or the given value
    d = properties[:publish_status].default.blank? ? @publish_states.first.to_s : properties[:publish_status].default
    
    # set the length to 10 if missing or if shorter than 5, otherwise use the given value
    l = 5  if properties[:publish_status].length.blank?
    l = (properties[:publish_status].length <= 10 ? 10 : properties[:publish_status].length)
    
    property :publish_status, String, :length => l, :default => d.to_s
  else
    # no such property, so adding it with default values
    property :publish_status, String, :length => 10, :default => @publish_states.first.to_s 
  end
  
  # create the state specific instance methods
  self.publish_states.each do |state|
    define_method("is_#{state}?") do 
      self.publish_status == state.to_s
    end
    define_method("save_as_#{state}") do 
      self.publish_status = state.to_s
      save
    end
  end
  
  # ensure we are always saving publish_status values as strings
  before :valid? do
    self.publish_status = self.publish_status.to_s if self.respond_to?(:publish_status)
  end
  
  validates_within    :publish_status, 
                      :set => @publish_states_for_validation,
                      :message => "The publish_status value can only be one of these values: [ #{@publish_states_for_validation.join(', ')} ]"
  
end