diff options
Diffstat (limited to 'activerecord/lib/active_record/attribute_set/builder.rb')
-rw-r--r-- | activerecord/lib/active_record/attribute_set/builder.rb | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/attribute_set/builder.rb b/activerecord/lib/active_record/attribute_set/builder.rb new file mode 100644 index 0000000000..05138ae36d --- /dev/null +++ b/activerecord/lib/active_record/attribute_set/builder.rb @@ -0,0 +1,84 @@ +module ActiveRecord + class AttributeSet # :nodoc: + class Builder # :nodoc: + attr_reader :types, :always_initialized + + def initialize(types, always_initialized = nil) + @types = types + @always_initialized = always_initialized + end + + def build_from_database(values = {}, additional_types = {}) + if always_initialized && !values.key?(always_initialized) + values[always_initialized] = nil + end + + attributes = LazyAttributeHash.new(types, values, additional_types) + AttributeSet.new(attributes) + end + end + end + + class LazyAttributeHash # :nodoc: + delegate :select, :transform_values, to: :materialize + + def initialize(types, values, additional_types) + @types = types + @values = values + @additional_types = additional_types + @materialized = false + @delegate_hash = {} + end + + def key?(key) + delegate_hash.key?(key) || values.key?(key) || types.key?(key) + end + + def [](key) + delegate_hash[key] || assign_default_value(key) + end + + def []=(key, value) + if frozen? + raise RuntimeError, "Can't modify frozen hash" + end + delegate_hash[key] = value + end + + def initialized_keys + delegate_hash.keys | values.keys + end + + def initialize_dup(_) + @delegate_hash = delegate_hash.transform_values(&:dup) + super + end + + protected + + attr_reader :types, :values, :additional_types, :delegate_hash + + private + + def assign_default_value(name) + type = additional_types.fetch(name, types[name]) + value_present = true + value = values.fetch(name) { value_present = false } + + if value_present + delegate_hash[name] = Attribute.from_database(name, value, type) + elsif types.key?(name) + delegate_hash[name] = Attribute.uninitialized(name, type) + end + end + + def materialize + unless @materialized + values.each_key { |key| self[key] } + types.each_key { |key| self[key] } + @materialized = true + end + delegate_hash + end + end +end |