Class: ActiveRecord::PredicateBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record/relation/predicate_builder.rb,
lib/active_record/relation/predicate_builder/array_handler.rb,
lib/active_record/relation/predicate_builder/relation_handler.rb

Overview

:nodoc:

Defined Under Namespace

Classes: ArrayHandler, RelationHandler

Class Method Summary collapse

Class Method Details

.build_from_hash(klass, attributes, default_table) ⇒ Object



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
# File 'lib/active_record/relation/predicate_builder.rb', line 18

def self.build_from_hash(klass, attributes, default_table)
  queries = []

  attributes.each do |column, value|
    table = default_table

    if value.is_a?(Hash)
      if value.empty?
        queries << '1=0'
      else
        table       = Arel::Table.new(column, default_table.engine)
        association = klass._reflect_on_association(column.to_sym)

        value.each do |k, v|
          queries.concat expand(association && association.klass, table, k, v)
        end
      end
    else
      column = column.to_s

      if column.include?('.')
        table_name, column = column.split('.', 2)
        table = Arel::Table.new(table_name, default_table.engine)
      end

      queries.concat expand(klass, table, column, value)
    end
  end

  queries
end

.expand(klass, table, column, value) ⇒ Object



50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
# File 'lib/active_record/relation/predicate_builder.rb', line 50

def self.expand(klass, table, column, value)
  queries = []

  # Find the foreign key when using queries such as:
  # Post.where(author: author)
  #
  # For polymorphic relationships, find the foreign key and type:
  # PriceEstimate.where(estimate_of: treasure)
  if klass && reflection = klass._reflect_on_association(column.to_sym)
    if reflection.polymorphic? && base_class = polymorphic_base_class_from_value(value)
      queries << build(table[reflection.foreign_type], base_class)
    end

    column = reflection.foreign_key
  end

  queries << build(table[column], value)
  queries
end

.polymorphic_base_class_from_value(value) ⇒ Object



70
71
72
73
74
75
76
77
78
79
80
# File 'lib/active_record/relation/predicate_builder.rb', line 70

def self.polymorphic_base_class_from_value(value)
  case value
  when Relation
    value.klass.base_class
  when Array
    val = value.compact.first
    val.class.base_class if val.is_a?(Base)
  when Base
    value.class.base_class
  end
end

.references(attributes) ⇒ Object



82
83
84
85
86
87
88
89
90
91
# File 'lib/active_record/relation/predicate_builder.rb', line 82

def self.references(attributes)
  attributes.map do |key, value|
    if value.is_a?(Hash)
      key
    else
      key = key.to_s
      key.split('.').first if key.include?('.')
    end
  end.compact
end

.register_handler(klass, handler) ⇒ Object

Define how a class is converted to Arel nodes when passed to where. The handler can be any object that responds to call, and will be used for any value that === the class given. For example:

MyCustomDateRange = Struct.new(:start, :end)
handler = proc do |column, range|
  Arel::Nodes::Between.new(column,
    Arel::Nodes::And.new([range.start, range.end])
  )
end
ActiveRecord::PredicateBuilder.register_handler(MyCustomDateRange, handler)


104
105
106
# File 'lib/active_record/relation/predicate_builder.rb', line 104

def self.register_handler(klass, handler)
  @handlers.unshift([klass, handler])
end

.resolve_column_aliases(klass, hash) ⇒ Object



8
9
10
11
12
13
14
15
16
# File 'lib/active_record/relation/predicate_builder.rb', line 8

def self.resolve_column_aliases(klass, hash)
  hash = hash.dup
  hash.keys.grep(Symbol) do |key|
    if klass.attribute_alias? key
      hash[klass.attribute_alias(key)] = hash.delete key
    end
  end
  hash
end