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# frozen_string_literal: true
module ActiveRecord
class PredicateBuilder # :nodoc:
require "active_record/relation/predicate_builder/array_handler"
require "active_record/relation/predicate_builder/basic_object_handler"
require "active_record/relation/predicate_builder/range_handler"
require "active_record/relation/predicate_builder/relation_handler"
require "active_record/relation/predicate_builder/association_query_value"
require "active_record/relation/predicate_builder/polymorphic_array_value"
def initialize(table)
@table = table
@handlers = []
register_handler(BasicObject, BasicObjectHandler.new(self))
register_handler(Range, RangeHandler.new(self))
register_handler(Relation, RelationHandler.new)
register_handler(Array, ArrayHandler.new(self))
register_handler(Set, ArrayHandler.new(self))
end
def build_from_hash(attributes, &block)
attributes = convert_dot_notation_to_hash(attributes)
expand_from_hash(attributes, &block)
end
def self.references(attributes)
attributes.each_with_object([]) do |(key, value), result|
if value.is_a?(Hash)
result << Arel.sql(key, retryable: true)
elsif (idx = key.rindex("."))
result << Arel.sql(key[0, idx], retryable: true)
end
end
end
# 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.new("users").register_handler(MyCustomDateRange, handler)
def register_handler(klass, handler)
@handlers.unshift([klass, handler])
end
def [](attr_name, value, operator = nil)
build(table.arel_table[attr_name], value, operator)
end
def build(attribute, value, operator = nil)
value = value.id if value.respond_to?(:id)
if operator ||= table.type(attribute.name).force_equality?(value) && :eq
bind = build_bind_attribute(attribute.name, value)
attribute.public_send(operator, bind)
else
handler_for(value).call(attribute, value)
end
end
def build_bind_attribute(column_name, value)
Relation::QueryAttribute.new(column_name, value, table.type(column_name))
end
def resolve_arel_attribute(table_name, column_name, &block)
table.associated_table(table_name, &block).arel_table[column_name]
end
protected
def expand_from_hash(attributes, &block)
return ["1=0"] if attributes.empty?
attributes.flat_map do |key, value|
if key.is_a?(Array)
queries = Array(value).map do |ids_set|
raise ArgumentError, "Expected corresponding value for #{key} to be an Array" unless ids_set.is_a?(Array)
expand_from_hash(key.zip(ids_set).to_h)
end
grouping_queries(queries)
elsif value.is_a?(Hash) && !table.has_column?(key)
table.associated_table(key, &block)
.predicate_builder.expand_from_hash(value.stringify_keys)
elsif table.associated_with?(key)
# 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)
associated_table = table.associated_table(key)
if associated_table.polymorphic_association?
value = [value] unless value.is_a?(Array)
klass = PolymorphicArrayValue
elsif associated_table.through_association?
next associated_table.predicate_builder.expand_from_hash(
associated_table.primary_key => value
)
end
klass ||= AssociationQueryValue
queries = klass.new(associated_table, value).queries.map! do |query|
# If the query produced is identical to attributes don't go any deeper.
# Prevents stack level too deep errors when association and foreign_key are identical.
query == attributes ? self[key, value] : expand_from_hash(query)
end
grouping_queries(queries)
elsif table.aggregated_with?(key)
mapping = table.reflect_on_aggregation(key).mapping
values = value.nil? ? [nil] : Array.wrap(value)
if mapping.length == 1 || values.empty?
column_name, aggr_attr = mapping.first
values = values.map do |object|
object.respond_to?(aggr_attr) ? object.public_send(aggr_attr) : object
end
self[column_name, values]
else
queries = values.map do |object|
mapping.map do |field_attr, aggregate_attr|
self[field_attr, object.try!(aggregate_attr)]
end
end
grouping_queries(queries)
end
else
self[key, value]
end
end
end
private
attr_reader :table
def grouping_queries(queries)
if queries.one?
queries.first
else
queries.map! { |query| query.reduce(&:and) }
queries = Arel::Nodes::Or.new(queries)
Arel::Nodes::Grouping.new(queries)
end
end
def convert_dot_notation_to_hash(attributes)
attributes.each_with_object({}) do |(key, value), converted|
if value.is_a?(Hash)
if (existing = converted[key])
existing.merge!(value)
else
converted[key] = value.dup
end
elsif (idx = key.rindex("."))
table_name, column_name = key[0, idx], key[idx + 1, key.length]
if (existing = converted[table_name])
existing[column_name] = value
else
converted[table_name] = { column_name => value }
end
else
converted[key] = value
end
end
end
def handler_for(object)
@handlers.detect { |klass, _| klass === object }.last
end
end
end
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