From 70ac072976c8cc6f013f0df3777e54ccae3f4f8c Mon Sep 17 00:00:00 2001 From: Sean Griffin Date: Fri, 30 Jan 2015 14:03:36 -0700 Subject: Attribute assignment and type casting has nothing to do with columns It's finally finished!!!!!!! The reason the Attributes API was kept private in 4.2 was due to some publicly visible implementation details. It was previously implemented by overloading `columns` and `columns_hash`, to make them return column objects which were modified with the attribute information. This meant that those methods LIED! We didn't change the database schema. We changed the attribute information on the class. That is wrong! It should be the other way around, where schema loading just calls the attributes API for you. And now it does! Yes, this means that there is nothing that happens in automatic schema loading that you couldn't manually do yourself. (There's still some funky cases where we hit the connection adapter that I need to handle, before we can turn off automatic schema detection entirely.) There were a few weird test failures caused by this that had to be fixed. The main source came from the fact that the attribute methods are now defined in terms of `attribute_names`, which has a clause like `return [] unless table_exists?`. I don't *think* this is an issue, since the only place this caused failures were in a fake adapter which didn't override `table_exists?`. Additionally, there were a few cases where tests were failing because a migration was run, but the model was not reloaded. I'm not sure why these started failing from this change, I might need to clear an additional cache in `reload_schema_from_cache`. Again, since this is not normal usage, and it's expected that `reset_column_information` will be called after the table is modified, I don't think it's a problem. Still, test failures that were unrelated to the change are worrying, and I need to dig into them further. Finally, I spent a lot of time debugging issues with the mutex used in `define_attribute_methods`. I think we can just remove that method entirely, and define the attribute methods *manually* in the call to `define_attribute`, which would simplify the code *tremendously*. Ok. now to make this damn thing public, and work on moving it up to Active Model. --- activerecord/lib/active_record/model_schema.rb | 79 +++++++++++++++++++------- 1 file changed, 59 insertions(+), 20 deletions(-) (limited to 'activerecord/lib/active_record/model_schema.rb') diff --git a/activerecord/lib/active_record/model_schema.rb b/activerecord/lib/active_record/model_schema.rb index af0b667262..293db1c57f 100644 --- a/activerecord/lib/active_record/model_schema.rb +++ b/activerecord/lib/active_record/model_schema.rb @@ -217,28 +217,37 @@ module ActiveRecord end def attributes_builder # :nodoc: - @attributes_builder ||= AttributeSet::Builder.new(column_types, primary_key) + @attributes_builder ||= AttributeSet::Builder.new(attribute_types, primary_key) end - def column_types # :nodoc: - @column_types ||= columns_hash.transform_values(&:cast_type).tap do |h| - h.default = Type::Value.new - end + def columns_hash # :nodoc: + load_schema + @columns_hash + end + + def columns + load_schema + @columns ||= columns_hash.values + end + + def attribute_types # :nodoc: + load_schema + @attribute_types ||= Hash.new(Type::Value.new) end def type_for_attribute(attr_name) # :nodoc: - column_types[attr_name] + attribute_types[attr_name] end # Returns a hash where the keys are column names and the values are # default values when instantiating the AR object for this table. def column_defaults + load_schema _default_attributes.to_hash end def _default_attributes # :nodoc: - @default_attributes ||= attributes_builder.build_from_database( - raw_default_values) + @default_attributes ||= AttributeSet.new({}) end # Returns an array of column names as strings. @@ -281,19 +290,53 @@ module ActiveRecord def reset_column_information connection.clear_cache! undefine_attribute_methods - connection.schema_cache.clear_table_cache!(table_name) if table_exists? + connection.schema_cache.clear_table_cache!(table_name) - @arel_engine = nil - @arel_table = nil - @column_names = nil - @column_types = nil - @content_columns = nil - @default_attributes = nil - @inheritance_column = nil unless defined?(@explicit_inheritance_column) && @explicit_inheritance_column + reload_schema_from_cache end private + def schema_loaded? + defined?(@columns_hash) && @columns_hash + end + + def load_schema + unless schema_loaded? + load_schema! + end + end + + def load_schema! + @columns_hash = connection.schema_cache.columns_hash(table_name) + @columns_hash.each do |name, column| + define_attribute( + name, + column.cast_type, + default: column.default, + user_provided_default: false + ) + end + end + + def reload_schema_from_cache + @arel_engine = nil + @arel_table = nil + @column_names = nil + @attribute_types = nil + @content_columns = nil + @default_attributes = nil + @inheritance_column = nil unless defined?(@explicit_inheritance_column) && @explicit_inheritance_column + @attributes_builder = nil + @column_names = nil + @attribute_types = nil + @columns = nil + @columns_hash = nil + @content_columns = nil + @default_attributes = nil + @attribute_names = nil + end + # Guesses the table name, but does not decorate it with prefix and suffix information. def undecorated_table_name(class_name = base_class.name) table_name = class_name.to_s.demodulize.underscore @@ -317,10 +360,6 @@ module ActiveRecord base.table_name end end - - def raw_default_values - columns_hash.transform_values(&:default) - end end end end -- cgit v1.2.3