Class: Miscellany::ArbitraryPrefetch::PrefetcherContext

Inherits:
Object
  • Object
show all
Defined in:
lib/miscellany/active_record/arbitrary_prefetch.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model, opts) ⇒ PrefetcherContext

Returns a new instance of PrefetcherContext.



16
17
18
19
20
21
22
23
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 16

def initialize(model, opts)
  @options = opts
  @model = model
  @source_key = opts[:relation]
  @target_attribute = opts[:attribute]
  @queryset = opts[:queryset]
  @models = []
end

Instance Attribute Details

#model ⇒ Object

Returns the value of attribute model.



13
14
15
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 13

def model
  @model
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



14
15
16
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 14

def options
  @options
end

#target_attribute ⇒ Object

Returns the value of attribute target_attribute.



13
14
15
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 13

def target_attribute
  @target_attribute
end

Instance Method Details



25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 25

def link_models(models)
  Array(models).each do |m|
    @models << m

    # assoc = PrefetchAssociation.new(m, self, reflection)
    assoc = reflection.association_class.new(m, reflection)
    m.send(:association_instance_set, target_attribute, assoc)

    m.instance_eval "      def \#{target_attribute}\n        association(:\#{target_attribute}).reader\n      end\n    CODE\n  end\nend\n", __FILE__, __LINE__ + 1

#reflection ⇒ Object 



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
 
# File 'lib/miscellany/active_record/arbitrary_prefetch.rb', line 41

def reflection
  @reflection ||= begin
    queryset = @queryset
    source_refl = model.reflections[@source_key.to_s]
    scope = lambda {|*_args|
      qs = queryset
      qs = qs.merge(source_refl.scope_for(model.unscoped)) if source_refl.scope
      qs
    }
    pass_opts = source_refl.options.merge(
      class_name: source_refl.class_name,
      inverse_of: nil,
      arbitrary_source_reflection: source_refl,
    )
    if source_refl.is_a?(ActiveRecord::Reflection::ThroughReflection)
      pass_opts[:source] = source_refl.source_reflection_name
    end
    ActiveRecord::Reflection.create(
      options[:type],
      @target_attribute,
      scope,
      pass_opts,
      model
    )
  end
end