module ActiveRecord
module SpawnMethods
def spawn(arel_table = self.table)
relation = Relation.new(@klass, arel_table)
(Relation::ASSOCIATION_METHODS + Relation::MULTI_VALUE_METHODS).each do |query_method|
relation.send(:"#{query_method}_values=", send(:"#{query_method}_values"))
end
Relation::SINGLE_VALUE_METHODS.each do |query_method|
relation.send(:"#{query_method}_value=", send(:"#{query_method}_value"))
end
relation
end
def merge(r)
if r.klass != @klass
raise ArgumentError, "Cannot merge a #{r.klass.name}(##{r.klass.object_id}) relation with #{@klass.name}(##{@klass.object_id}) relation"
end
merged_relation = spawn.eager_load(r.eager_load_values).preload(r.preload_values).includes(r.includes_values)
merged_relation.readonly_value = r.readonly_value unless r.readonly_value.nil?
merged_relation.limit_value = r.limit_value if r.limit_value.present?
merged_relation.lock_value = r.lock_value unless merged_relation.lock_value
merged_relation.offset_value = r.offset_value if r.offset_value.present?
merged_relation = merged_relation.
joins(r.joins_values).
group(r.group_values).
select(r.select_values).
from(r.from_value).
having(r.having_values)
merged_relation.order_values = Array.wrap(order_values) + Array.wrap(r.order_values)
merged_relation.create_with_value = @create_with_value
if @create_with_value && r.create_with_value
merged_relation.create_with_value = @create_with_value.merge(r.create_with_value)
else
merged_relation.create_with_value = r.create_with_value || @create_with_value
end
merged_wheres = @where_values
r.where_values.each do |w|
if w.is_a?(Arel::Predicates::Equality)
merged_wheres = merged_wheres.reject {|p| p.is_a?(Arel::Predicates::Equality) && p.operand1.name == w.operand1.name }
end
merged_wheres += [w]
end
merged_relation.where_values = merged_wheres
merged_relation
end
alias :& :merge
def except(*skips)
result = Relation.new(@klass, table)
(Relation::ASSOCIATION_METHODS + Relation::MULTI_VALUE_METHODS).each do |method|
result.send(:"#{method}_values=", send(:"#{method}_values")) unless skips.include?(method)
end
Relation::SINGLE_VALUE_METHODS.each do |method|
result.send(:"#{method}_value=", send(:"#{method}_value")) unless skips.include?(method)
end
result
end
def only(*onlies)
result = Relation.new(@klass, table)
onlies.each do |only|
if (Relation::ASSOCIATION_METHODS + Relation::MULTI_VALUE_METHODS).include?(only)
result.send(:"#{only}_values=", send(:"#{only}_values"))
elsif Relation::SINGLE_VALUE_METHODS.include?(only)
result.send(:"#{only}_value=", send(:"#{only}_value"))
else
raise "Invalid argument : #{only}"
end
end
result
end
VALID_FIND_OPTIONS = [ :conditions, :include, :joins, :limit, :offset,
:order, :select, :readonly, :group, :having, :from, :lock ]
def apply_finder_options(options)
options.assert_valid_keys(VALID_FIND_OPTIONS)
relation = spawn
relation = relation.joins(options[:joins]).
where(options[:conditions]).
select(options[:select]).
group(options[:group]).
having(options[:having]).
order(options[:order]).
limit(options[:limit]).
offset(options[:offset]).
from(options[:from]).
includes(options[:include])
relation = relation.lock(options[:lock]) if options[:lock].present?
relation = relation.readonly(options[:readonly]) if options.has_key?(:readonly)
relation
end
end
end