Module: GroupedModel::ClassMethods

Defined in:
lib/grouped_model.rb

Instance Method Summary collapse

Instance Method Details

#has_groups(options = {}) ⇒ Object Also known as: has_group

Sets up group relations and scopes in this model. No extra columns are required in the model table.



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# File 'lib/grouped_model.rb', line 34

def has_groups(options={})
  return if has_groups?
  
  class_eval {
    include GroupedModel::GroupedInstanceMethods

    def self.has_groups?
      true
    end
    
    def self.visible
      ungrouped
    end
  }
  
  has_many :permissions, :as => :permitted
  accepts_nested_attributes_for :permissions
  has_many :groups, :through => :permissions
  Group.define_retrieval_methods(self.to_s)

  named_scope :visible_to, lambda { |reader| 
    conditions = "pp.group_id IS NULL"
    if reader && reader.is_grouped?
      ids = reader.group_ids
      conditions = ["#{conditions} OR pp.group_id IS NULL OR pp.group_id IN(#{ids.map{"?"}.join(',')})", *ids]
    end
    {
      :joins => "LEFT OUTER JOIN permissions as pp on pp.permitted_id = #{self.table_name}.id AND pp.permitted_type = '#{self.to_s}'",
      :group => column_names.map { |n| self.table_name + '.' + n }.join(','),
      :conditions => conditions,
      :readonly => false
    } 
  }

  named_scope :ungrouped, lambda {
    {
      :select => "#{self.table_name}.*, count(pp.id) as group_count",
      :joins => "LEFT OUTER JOIN permissions as pp on pp.permitted_id = #{self.table_name}.id AND pp.permitted_type = '#{self.to_s}'", 
      :having => "group_count = 0",
      :group => column_names.map { |n| self.table_name + '.' + n }.join(','),    # postgres requires that we group by all selected (but not aggregated) columns
      :readonly => false
    }
  } do
    def count
      length
    end
  end

  named_scope :grouped, lambda {
      {
      :select => "#{self.table_name}.*, count(pp.id) as group_count",
      :joins => "LEFT OUTER JOIN permissions as pp on pp.permitted_id = #{self.table_name}.id AND pp.permitted_type = '#{self.to_s}'", 
      :having => "group_count > 0",
      :group => column_names.map { |n| self.table_name + '.' + n }.join(','),
      :readonly => false
    }
  } do
    def count
      length
    end
  end
  
  named_scope :belonging_to, lambda { |group|
    {
      :joins => "INNER JOIN permissions as pp on pp.permitted_id = #{self.table_name}.id AND pp.permitted_type = '#{self.to_s}'", 
      :group => column_names.map { |n| self.table_name + '.' + n }.join(','),
      :conditions => ["pp.group_id = ?", group.id],
      :readonly => false
    }
  }
  
  named_scope :find_these, lambda { |ids|
    ids = ['NULL'] unless ids && ids.any?
    { :conditions => ["#{self.table_name}.id IN (#{ids.map{"?"}.join(',')})", *ids] }
  }
        
end

#has_groups? ⇒ Boolean Also known as: has_group?

Returns true if group relations have been established in this model.

Returns:

  • (Boolean) 


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# File 'lib/grouped_model.rb', line 27

def has_groups?
  false
end