Class: DataMapper::Associations::HasAndBelongsToManyAssociation

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/data_mapper/associations/has_and_belongs_to_many_association.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(instance, association_name, options) ⇒ HasAndBelongsToManyAssociation

Returns a new instance of HasAndBelongsToManyAssociation.



7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 7

def initialize(instance, association_name, options)
  @instance = instance
  @association_name = association_name.to_sym
  @options = options
  
  @associated_class = if options.has_key?(:class) || options.has_key?(:class_name)
    associated_class_name = (options[:class] || options[:class_name])
    if associated_class_name.kind_of?(String)
      Kernel.const_get(Inflector.classify(associated_class_name))
    else
      associated_class_name
    end
  else            
    Kernel.const_get(Inflector.classify(association_name))
  end
  
  @join_table_name = @options.has_key?(:join_table_name) ? @options[:join_table_name] : [Inflector.tableize(@instance.class.name), Inflector.tableize(@associated_class.name)].sort.join('_')
end

Class Method Details

.setup(klass, association_name, options) ⇒ Object 



26
27
28
29
30
31
32
33
34
35
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 26

def self.setup(klass, association_name, options)
  
  # Define the association instance method (i.e. Project#tasks)
  klass.class_eval <<-EOS
    def #{association_name}
      @#{association_name} || (@#{association_name} = HasAndBelongsToManyAssociation.new(self, "#{association_name}", #{options.inspect}))
    end
  EOS
  
end

Instance Method Details

#[](key) ⇒ Object 



46
47
48
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 46

def [](key)
  entries[key]
end

#each ⇒ Object 



37
38
39
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 37

def each
  find.each { |item| yield item }
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


50
51
52
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 50

def empty?
  entries.empty?
end

#find ⇒ Object 



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 54

def find
  return @results unless @results.nil?
  
  unless @instance.loaded_set.nil?
    
    # Temp variable for the instance variable name.
    instance_variable_name = "@#{foreign_key}".to_sym
    
    @results = @instance.session.find(@associated_class, :all,
      :id.select => { :table => @join_table_name, foreign_key.to_sym => @instance.key }
    ) do |animal_id, ref|
      @instance.load_set.find { |x| x.id == animal_id }.exhibits << ref
    end
    
  end
  
  return @results || (@results = [])
end

#foreign_key ⇒ Object 



81
82
83
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 81

def foreign_key
  @foreign_key || (@foreign_key = (@options[:foreign_key] || @instance.session.mappings[@instance.class].default_foreign_key))
end

#inspect ⇒ Object 



77
78
79
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 77

def inspect
  @results.inspect
end

#set(results) ⇒ Object 



73
74
75
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 73

def set(results)
  @results = results
end

#size ⇒ Object Also known as: length 



41
42
43
 
# File 'lib/data_mapper/associations/has_and_belongs_to_many_association.rb', line 41

def size
  entries.size
end