class Mongoid::Criteria::Queryable::Selector
The selector is a special kind of hash that knows how to serialize values coming into it as well as being alias and locale aware for key names.
Public Instance Methods
Merges another selector into this one.
@example Merge in another selector.
selector.merge!(name: "test")
@param [ Hash | Selector
] other The object to merge in.
@return [ Selector
] The selector.
# File lib/mongoid/criteria/queryable/selector.rb, line 20 def merge!(other) other.each_pair do |key, value| if value.is_a?(Hash) && self[key.to_s].is_a?(Hash) value = self[key.to_s].merge(value) do |_key, old_val, new_val| case _key.to_s when '$in' new_val & old_val when '$nin' (old_val + new_val).uniq else new_val end end end if multi_selection?(key) value = (self[key.to_s] || []).concat(value) end store(key, value) end end
Store the value in the selector for the provided key. The selector will handle all necessary serialization and localization in this step.
@example Store a value in the selector.
selector.store(:key, "testing")
@param [ String | Symbol ] key The name of the attribute. @param [ Object
] value The value to add.
@return [ Object
] The stored object.
# File lib/mongoid/criteria/queryable/selector.rb, line 51 def store(key, value) name, serializer = storage_pair(key) if multi_selection?(name) store_name = name store_value = evolve_multi(value) else store_name, store_value = store_creds(name, serializer, value) end super(store_name, store_value) end
Convert the selector to an aggregation pipeline entry.
@example Convert the selector to a pipeline.
selector.to_pipeline
@return [ Array<Hash> ] The pipeline entry for the selector.
# File lib/mongoid/criteria/queryable/selector.rb, line 69 def to_pipeline pipeline = [] pipeline.push({ "$match" => self }) unless empty? pipeline end
Private Instance Methods
Evolve a single key selection with various types of values.
@api private
@example Evolve a simple selection.
selector.evolve(field, 5)
@param [ Object
] serializer The optional serializer for the field. @param [ Object
] value The value to serialize.
@return [ Object
] The serialized object.
# File lib/mongoid/criteria/queryable/selector.rb, line 153 def evolve(serializer, value) case value when Mongoid::RawValue value.raw_value when Hash evolve_hash(serializer, value) when Array evolve_array(serializer, value) when Range value.__evolve_range__(serializer: serializer) else (serializer || value.class).evolve(value) end end
Evolve a single key selection with array values.
@api private
@example Evolve a simple selection.
selector.evolve(field, [ 1, 2, 3 ])
@param [ Object
] serializer The optional serializer for the field. @param [ Array<Object> ] value The array to serialize.
@return [ Object
] The serialized array.
# File lib/mongoid/criteria/queryable/selector.rb, line 179 def evolve_array(serializer, value) value.map do |_value| evolve(serializer, _value) end end
Evolve a single key selection with hash values.
@api private
@example Evolve a simple selection.
selector.evolve(field, { "$gt" => 5 })
@param [ Object
] serializer The optional serializer for the field. @param [ Hash ] value The hash to serialize.
@return [ Object
] The serialized hash.
# File lib/mongoid/criteria/queryable/selector.rb, line 196 def evolve_hash(serializer, value) value.each_pair do |operator, _value| if operator =~ /exists|type|size/ value[operator] = _value else value[operator] = evolve(serializer, _value) end end end
Evolves a multi-list selection, like an $and or $or criterion, and performs the necessary serialization.
@example Evolve the multi-selection.
selector.evolve_multi([{ field: "value" }])
@param [ Array<Hash> ] specs The multi-selection.
@return [ Array<Hash> ] The serialized values.
@api private
# File lib/mongoid/criteria/queryable/selector.rb, line 106 def evolve_multi(specs) unless specs.is_a?(Array) raise ArgumentError, "specs is not an array: #{specs.inspect}" end specs.map do |spec| Hash[spec.map do |key, value| # If an application nests conditionals, e.g. # {'$or' => [{'$or' => {...}}]}, # when evolve_multi is called for the top level hash, # this call recursively transforms the bottom level $or. if multi_selection?(key) value = evolve_multi(value) end # storage_pair handles field aliases but not localization for # some reason, although per its documentation Smash supposedly # owns both. name, serializer = storage_pair(key) # This performs type conversions on the value and transformations # that depend on the type of the field that the value is stored # in, but not transformations that have to do with query shape. final_key, evolved_value = store_creds(name, serializer, value) # This builds a query shape around the value, when the query # involves complex keys. For example, {:foo.lt => 5} produces # {'foo' => {'$lt' => 5}}. This step should be done after all # value-based processing is complete. if key.is_a?(Key) evolved_value = key.transform_value(evolved_value) end [ final_key, evolved_value ] end] end.uniq end
Evolve a single key selection with range values. This method traverses the association tree to build a query for the given value and serializer. There are three parts to the query here:
(1) “klass.child.gchild” => {
"$elemMatch" => { (2) "ggchild.field" => (3) { "$gte" => 6, "$lte" => 10 } } }
(1) The first n fields are dotted together until the last
embeds_many or field of type array. In the above case, gchild would be an embeds_many or Array, and ggchild would be an embeds_one or a hash.
(2) The last fields are used inside the $elemMatch. This one is
actually optional, and will be ignored if the last field is an array or embeds_many. If the last field is an array (1), (2) and (3) will look like: "klass.child.gchild.ggchild.field" => { { "$elemMatch" => { "$gte" => 6, "$lte" => 10 } } }
(3) This is calculated by:
value.__evolve_range__(serializer: serializer).
@api private
@param [ String ] key The key at which to store the range. @param [ Object
] serializer The optional serializer for the field. @param [ Range ] value The Range to serialize.
@return [ Array<String, Hash> ] The store name and serialized Range.
# File lib/mongoid/criteria/queryable/selector.rb, line 239 def evolve_range(key, serializer, value) v = value.__evolve_range__(serializer: serializer) assocs = [] Fields.traverse_association_tree(key, serializers, associations, aliased_associations) do |meth, obj, is_field| assocs.push([meth, obj, is_field]) end # Iterate backwards until you get a field with type # Array or an embeds_many association. inner_key = "" loop do # If there are no arrays or embeds_many associations, just return # the key and value without $elemMatch. return [ key, v ] if assocs.empty? meth, obj, is_field = assocs.last break if (is_field && obj.type == Array) || (!is_field && obj.is_a?(Association::Embedded::EmbedsMany)) assocs.pop inner_key = "#{meth}.#{inner_key}" end # If the last array or embeds_many association is the last field, # the inner key (2) is ignored, and the outer key (1) is the original # key. if inner_key.blank? [ key, { "$elemMatch" => v }] else store_key = assocs.map(&:first).join('.') store_value = { "$elemMatch" => { inner_key.chop => v } } [ store_key, store_value ] end end
Determines if the selection is a multi-select, like an $and or $or or $nor selection.
@api private
@example Is the selection a multi-select?
selector.multi_selection?("$and")
@param [ String ] key The key to check.
@return [ true | false ] If the key is for a multi-select.
# File lib/mongoid/criteria/queryable/selector.rb, line 284 def multi_selection?(key) %w($and $or $nor).include?(key) end
Get the store name and store value. If the value is of type range, we need may need to change the store_name as well as the store_value, therefore, we cannot just use the evolve method.
@param [ String ] name The name of the field. @param [ Object
] serializer The optional serializer for the field. @param [ Object
] value The value to serialize.
@return [ Array<String, String> ] The store name and store value.
# File lib/mongoid/criteria/queryable/selector.rb, line 86 def store_creds(name, serializer, value) store_name = localized_key(name, serializer) if Range === value evolve_range(store_name, serializer, value) else [ store_name, evolve(serializer, value) ] end end