module ActiveRecord
module FinderMethods
def find(*ids, &block)
return to_a.find(&block) if block_given?
expects_array = ids.first.kind_of?(Array)
return ids.first if expects_array && ids.first.empty?
ids = ids.flatten.compact.uniq
case ids.size
when 0
raise RecordNotFound, "Couldn't find #{@klass.name} without an ID"
when 1
result = find_one(ids.first)
expects_array ? [ result ] : result
else
find_some(ids)
end
end
def exists?(id = nil)
relation = select(primary_key).limit(1)
relation = relation.where(primary_key.eq(id)) if id
relation.first ? true : false
end
def first
if loaded?
@records.first
else
@first ||= limit(1).to_a[0]
end
end
def last
if loaded?
@records.last
else
@last ||= reverse_order.limit(1).to_a[0]
end
end
protected
def find_with_associations
including = (@eager_load_values + @includes_values).uniq
join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, including, nil)
rows = construct_relation_for_association_find(join_dependency).to_a
join_dependency.instantiate(rows)
rescue ThrowResult
[]
end
def construct_relation_for_association_calculations
including = (@eager_load_values + @includes_values).uniq
join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, including, arel.joins(arel))
construct_relation_for_association_find(join_dependency)
end
def construct_relation_for_association_find(join_dependency)
relation = except(:includes, :eager_load, :preload, :select).select(@klass.send(:column_aliases, join_dependency))
for association in join_dependency.join_associations
relation = association.join_relation(relation)
end
limitable_reflections = @klass.send(:using_limitable_reflections?, join_dependency.reflections)
if !limitable_reflections && relation.limit_value
limited_id_condition = construct_limited_ids_condition(relation.except(:select))
relation = relation.where(limited_id_condition)
end
relation = relation.except(:limit, :offset) unless limitable_reflections
relation
end
def construct_limited_ids_condition(relation)
orders = relation.order_values.join(", ")
values = @klass.connection.distinct("#{@klass.connection.quote_table_name @klass.table_name}.#{@klass.primary_key}", orders)
ids_array = relation.select(values).collect {|row| row[@klass.primary_key]}
ids_array.empty? ? raise(ThrowResult) : primary_key.in(ids_array)
end
def find_by_attributes(match, attributes, *args)
conditions = attributes.inject({}) {|h, a| h[a] = args[attributes.index(a)]; h}
result = where(conditions).send(match.finder)
if match.bang? && result.blank?
raise RecordNotFound, "Couldn't find #{@klass.name} with #{conditions.to_a.collect {|p| p.join(' = ')}.join(', ')}"
else
result
end
end
def find_or_instantiator_by_attributes(match, attributes, *args)
guard_protected_attributes = false
if args[0].is_a?(Hash)
guard_protected_attributes = true
attributes_for_create = args[0].with_indifferent_access
conditions = attributes_for_create.slice(*attributes).symbolize_keys
else
attributes_for_create = conditions = attributes.inject({}) {|h, a| h[a] = args[attributes.index(a)]; h}
end
record = where(conditions).first
unless record
record = @klass.new { |r| r.send(:attributes=, attributes_for_create, guard_protected_attributes) }
yield(record) if block_given?
record.save if match.instantiator == :create
end
record
end
def find_one(id)
record = where(primary_key.eq(id)).first
unless record
conditions = where_clause(', ')
conditions = " [WHERE #{conditions}]" if conditions.present?
raise RecordNotFound, "Couldn't find #{@klass.name} with ID=#{id}#{conditions}"
end
record
end
def find_some(ids)
result = where(primary_key.in(ids)).all
expected_size =
if arel.taken && ids.size > arel.taken
arel.taken
else
ids.size
end
# 11 ids with limit 3, offset 9 should give 2 results.
if arel.skipped && (ids.size - arel.skipped < expected_size)
expected_size = ids.size - arel.skipped
end
if result.size == expected_size
result
else
conditions = where_clause(', ')
conditions = " [WHERE #{conditions}]" if conditions.present?
error = "Couldn't find all #{@klass.name.pluralize} with IDs "
error << "(#{ids.join(", ")})#{conditions} (found #{result.size} results, but was looking for #{expected_size})"
raise RecordNotFound, error
end
end
end
end
