Add named scopes and chainable scopes to any Object / Model.

• As gem: sudo gem install scopify
• As Rails plugin: rails plugin install git://github.com/grosser/scopify.git

Usage

With framework:

• MongoMapper
  MongoMapper::Document::ClassMethods.send(:include, Scopify::ClassMethods) MongoMapper::Plugins::Associations::Proxy.send(:include, Scopify::ClassMethods)
• Add another ;)

scoped

Create a scope on the fly. MyDBWrapper.scoped(:limit => 10).scoped(:order => "something").all(:offset => 1) --> MyDBWrapper.all receives: {:limit => 10, :order => "something", :offset => 1}

scope

Create named scopes, with options, lambdas or other scopes class MyDBWrapper include Scopify scope :good, :conditions => {:good => true} scope :okay, good.scoped(:conditions => {:goodness => [1,2,3]} scope :goodness, lambda{|factor| {:conditions => {:goodness => factor}} } end

MyDBWrapper.good.first
MyDBWrapper.good.goodness(3).first

simple_scope

Defines otherwise repetitive named scopes for you.

simple_scope :limit, :order, :where => :conditions
--> MyDBWrapper.limit(3).order('foo').where("1 = 2") == 
    {:limit => 3, :order => 'foo', :conditions => "1 = 2"}

Custom scope helpers

class MyDBWrapper
  def self.foo(num)
    scoped(:foo => num)
  end

  def self.bar(num)
    scoped(:bar => num)
  end

  # tell scopes to pass raw arguments to foo and bar (not merged options hash)
  def self.raw_args_from_scope?(method_name)
    return true if super
    [:foo, :bar].include?(method_name)
  end
end

MyDBWrapper.foo(1).bar(3) == MyDBWrapper.scoped(:foo => 1, :bar => 3)

scope_to_hash

Roll your own condition composing. # not good ? MyDBWrapper.scoped(:order => 'a').scoped(:order => 'b).all --> {:order => "a, b"}

# roll your own !
class MyDBWrapper
  def self.scope_to_hash(options)
    options.map do |key, values|
      value = case key
      when :limit, :offset then values.min
      when :order then values.join(' AND ')
      else values.join(', ')
      end
      [key, value]
    end
  end
end

# better now !
MyDBWrapper.scoped(:order => 'a').scoped(:order => 'b).all --> {:order => "a AND b"}

Author

Michael Grosser
grosser.michael@gmail.com
Hereby placed under public domain, do what you want, just do not hold me accountable...