1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
require 'active_support/core_ext/object/blank'
module ActiveRecord
# = Active Record Has Many Through Association
module Associations
class HasManyThroughAssociation < HasManyAssociation #:nodoc:
include ThroughAssociation
def initialize(owner, reflection)
super
@through_records = {}
@through_association = nil
end
# Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been
# loaded and calling collection.size if it has. If it's more likely than not that the collection does
# have a size larger than zero, and you need to fetch that collection afterwards, it'll take one fewer
# SELECT query if you use #length.
def size
if has_cached_counter?
owner.send(:read_attribute, cached_counter_attribute_name)
elsif loaded?
target.size
else
count
end
end
def concat(*records)
unless owner.new_record?
records.flatten.each do |record|
raise_on_type_mismatch(record)
record.save! if record.new_record?
end
end
super
end
def insert_record(record, validate = true, raise = false)
ensure_not_nested
if record.new_record?
if raise
record.save!(:validate => validate)
else
return unless record.save(:validate => validate)
end
end
save_through_record(record)
update_counter(1)
record
end
# ActiveRecord::Relation#delete_all needs to support joins before we can use a
# SQL-only implementation.
alias delete_all_on_destroy delete_all
private
def through_association
@through_association ||= owner.association(through_reflection.name)
end
# We temporarily cache through record that has been build, because if we build a
# through record in build_record and then subsequently call insert_record, then we
# want to use the exact same object.
#
# However, after insert_record has been called, we clear the cache entry because
# we want it to be possible to have multiple instances of the same record in an
# association
def build_through_record(record)
@through_records[record.object_id] ||= begin
ensure_mutable
through_record = through_association.build
through_record.send("#{source_reflection.name}=", record)
through_record
end
end
def save_through_record(record)
build_through_record(record).save!
ensure
@through_records.delete(record.object_id)
end
def build_record(attributes, options = {})
ensure_not_nested
record = super(attributes, options)
inverse = source_reflection.inverse_of
if inverse
if inverse.macro == :has_many
record.send(inverse.name) << build_through_record(record)
elsif inverse.macro == :has_one
record.send("#{inverse.name}=", build_through_record(record))
end
end
record
end
def target_reflection_has_associated_record?
if through_reflection.macro == :belongs_to && owner[through_reflection.foreign_key].blank?
false
else
true
end
end
def update_through_counter?(method)
case method
when :destroy
!inverse_updates_counter_cache?(through_reflection)
when :nullify
false
else
true
end
end
def delete_records(records, method)
ensure_not_nested
scope = through_association.scoped.where(construct_join_attributes(*records))
case method
when :destroy
count = scope.destroy_all.length
when :nullify
count = scope.update_all(source_reflection.foreign_key => nil)
else
count = scope.delete_all
end
delete_through_records(records)
if through_reflection.macro == :has_many && update_through_counter?(method)
update_counter(-count, through_reflection)
end
update_counter(-count)
end
def through_records_for(record)
attributes = construct_join_attributes(record)
candidates = Array.wrap(through_association.target)
candidates.find_all { |c| c.attributes.slice(*attributes.keys) == attributes }
end
def delete_through_records(records)
records.each do |record|
through_records = through_records_for(record)
if through_reflection.macro == :has_many
through_records.each { |r| through_association.target.delete(r) }
else
if through_records.include?(through_association.target)
through_association.target = nil
end
end
@through_records.delete(record.object_id)
end
end
def find_target
return [] unless target_reflection_has_associated_record?
scoped.all
end
# NOTE - not sure that we can actually cope with inverses here
def invertible_for?(record)
false
end
end
end
end
|