diff options
Diffstat (limited to 'activesupport/lib/active_support/new_callbacks.rb')
| -rw-r--r-- | activesupport/lib/active_support/new_callbacks.rb | 563 |
1 files changed, 0 insertions, 563 deletions
diff --git a/activesupport/lib/active_support/new_callbacks.rb b/activesupport/lib/active_support/new_callbacks.rb deleted file mode 100644 index 2f0853d84a..0000000000 --- a/activesupport/lib/active_support/new_callbacks.rb +++ /dev/null @@ -1,563 +0,0 @@ -require 'active_support/core_ext/array/wrap' -require 'active_support/core_ext/class/inheritable_attributes' -require 'active_support/core_ext/kernel/reporting' - -module ActiveSupport - # Callbacks are hooks into the lifecycle of an object that allow you to trigger logic - # before or after an alteration of the object state. - # - # Mixing in this module allows you to define callbacks in your class. - # - # Example: - # class Storage - # include ActiveSupport::Callbacks - # - # define_callbacks :save - # end - # - # class ConfigStorage < Storage - # set_callback :save, :before, :saving_message - # def saving_message - # puts "saving..." - # end - # - # set_callback :save, :after do |object| - # puts "saved" - # end - # - # def save - # _run_set_callback :save,s do - # puts "- save" - # end - # end - # end - # - # config = ConfigStorage.new - # config.save - # - # Output: - # saving... - # - save - # saved - # - # Callbacks from parent classes are inherited. - # - # Example: - # class Storage - # include ActiveSupport::Callbacks - # - # define_callbacks :save - # - # set_callback :save, :before, :prepare - # def prepare - # puts "preparing save" - # end - # end - # - # class ConfigStorage < Storage - # set_callback :save, :before, :saving_message - # def saving_message - # puts "saving..." - # end - # - # set_callback :save, :after do |object| - # puts "saved" - # end - # - # def save - # _run_set_callback :save,s do - # puts "- save" - # end - # end - # end - # - # config = ConfigStorage.new - # config.save - # - # Output: - # preparing save - # saving... - # - save - # saved - # - module NewCallbacks - def self.included(klass) - klass.extend ClassMethods - end - - def run_callbacks(kind, options = {}, &blk) - send("_run_#{kind}_callbacks", &blk) - end - - class Callback - @@_callback_sequence = 0 - - attr_accessor :chain, :filter, :kind, :options, :per_key, :klass - - def initialize(chain, filter, kind, options, klass) - @chain, @kind, @klass = chain, kind, klass - normalize_options!(options) - - @per_key = options.delete(:per_key) - @raw_filter, @options = filter, options - @filter = _compile_filter(filter) - @compiled_options = _compile_options(options) - @callback_id = next_id - - _compile_per_key_options - end - - def clone(chain, klass) - obj = super() - obj.chain = chain - obj.klass = klass - obj.per_key = @per_key.dup - obj.options = @options.dup - obj.per_key[:if] = @per_key[:if].dup - obj.per_key[:unless] = @per_key[:unless].dup - obj.options[:if] = @options[:if].dup - obj.options[:unless] = @options[:unless].dup - obj - end - - def normalize_options!(options) - options[:if] = Array.wrap(options[:if]) - options[:unless] = Array.wrap(options[:unless]) - - options[:per_key] ||= {} - options[:per_key][:if] = Array.wrap(options[:per_key][:if]) - options[:per_key][:unless] = Array.wrap(options[:per_key][:unless]) - end - - def name - chain.name - end - - def next_id - @@_callback_sequence += 1 - end - - def matches?(_kind, _filter) - @kind == _kind && @filter == _filter - end - - def _update_filter(filter_options, new_options) - filter_options[:if].push(new_options[:unless]) if new_options.key?(:unless) - filter_options[:unless].push(new_options[:if]) if new_options.key?(:if) - end - - def recompile!(_options, _per_key) - _update_filter(self.options, _options) - _update_filter(self.per_key, _per_key) - - @callback_id = next_id - @filter = _compile_filter(@raw_filter) - @compiled_options = _compile_options(@options) - _compile_per_key_options - end - - def _compile_per_key_options - key_options = _compile_options(@per_key) - - @klass.class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 - def _one_time_conditions_valid_#{@callback_id}? - true #{key_options[0]} - end - RUBY_EVAL - end - - # This will supply contents for before and around filters, and no - # contents for after filters (for the forward pass). - def start(key=nil, object=nil) - return if key && !object.send("_one_time_conditions_valid_#{@callback_id}?") - - # options[0] is the compiled form of supplied conditions - # options[1] is the "end" for the conditional - # - if @kind == :before || @kind == :around - if @kind == :before - # if condition # before_save :filter_name, :if => :condition - # filter_name - # end - filter = <<-RUBY_EVAL - unless halted - result = #{@filter} - halted = (#{chain.config[:terminator]}) - end - RUBY_EVAL - - [@compiled_options[0], filter, @compiled_options[1]].compact.join("\n") - else - # Compile around filters with conditions into proxy methods - # that contain the conditions. - # - # For `around_save :filter_name, :if => :condition': - # - # def _conditional_callback_save_17 - # if condition - # filter_name do - # yield self - # end - # else - # yield self - # end - # end - # - name = "_conditional_callback_#{@kind}_#{next_id}" - txt, line = <<-RUBY_EVAL, __LINE__ + 1 - def #{name}(halted) - #{@compiled_options[0] || "if true"} && !halted - #{@filter} do - yield self - end - else - yield self - end - end - RUBY_EVAL - @klass.class_eval(txt, __FILE__, line) - "#{name}(halted) do" - end - end - end - - # This will supply contents for around and after filters, but not - # before filters (for the backward pass). - def end(key=nil, object=nil) - return if key && !object.send("_one_time_conditions_valid_#{@callback_id}?") - - if @kind == :around || @kind == :after - # if condition # after_save :filter_name, :if => :condition - # filter_name - # end - if @kind == :after - [@compiled_options[0], @filter, @compiled_options[1]].compact.join("\n") - else - "end" - end - end - end - - private - - # Options support the same options as filters themselves (and support - # symbols, string, procs, and objects), so compile a conditional - # expression based on the options - def _compile_options(options) - return [] if options[:if].empty? && options[:unless].empty? - - conditions = [] - - unless options[:if].empty? - conditions << Array.wrap(_compile_filter(options[:if])) - end - - unless options[:unless].empty? - conditions << Array.wrap(_compile_filter(options[:unless])).map {|f| "!#{f}"} - end - - ["if #{conditions.flatten.join(" && ")}", "end"] - end - - # Filters support: - # - # Arrays:: Used in conditions. This is used to specify - # multiple conditions. Used internally to - # merge conditions from skip_* filters - # Symbols:: A method to call - # Strings:: Some content to evaluate - # Procs:: A proc to call with the object - # Objects:: An object with a before_foo method on it to call - # - # All of these objects are compiled into methods and handled - # the same after this point: - # - # Arrays:: Merged together into a single filter - # Symbols:: Already methods - # Strings:: class_eval'ed into methods - # Procs:: define_method'ed into methods - # Objects:: - # a method is created that calls the before_foo method - # on the object. - # - def _compile_filter(filter) - method_name = "_callback_#{@kind}_#{next_id}" - case filter - when Array - filter.map {|f| _compile_filter(f)} - when Symbol - filter - when String - "(#{filter})" - when Proc - @klass.send(:define_method, method_name, &filter) - return method_name if filter.arity <= 0 - - method_name << (filter.arity == 1 ? "(self)" : " self, Proc.new ") - else - @klass.send(:define_method, "#{method_name}_object") { filter } - - _normalize_legacy_filter(kind, filter) - scopes = Array.wrap(chain.config[:scope]) - method_to_call = scopes.map{ |s| s.is_a?(Symbol) ? send(s) : s }.join("_") - - @klass.class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 - def #{method_name}(&blk) - #{method_name}_object.send(:#{method_to_call}, self, &blk) - end - RUBY_EVAL - - method_name - end - end - - def _normalize_legacy_filter(kind, filter) - if !filter.respond_to?(kind) && filter.respond_to?(:filter) - filter.metaclass.class_eval( - "def #{kind}(context, &block) filter(context, &block) end", - __FILE__, __LINE__ - 1) - elsif filter.respond_to?(:before) && filter.respond_to?(:after) && kind == :around - def filter.around(context) - should_continue = before(context) - yield if should_continue - after(context) - end - end - end - end - - # An Array with a compile method - class CallbackChain < Array - attr_reader :name, :config - - def initialize(name, config) - @name = name - @config = { - :terminator => "false", - :rescuable => false, - :scope => [ :kind ] - }.merge(config) - end - - def compile(key=nil, object=nil) - method = [] - method << "value = nil" - method << "halted = false" - - each do |callback| - method << callback.start(key, object) - end - - if config[:rescuable] - method << "rescued_error = nil" - method << "begin" - end - - method << "value = yield if block_given? && !halted" - - if config[:rescuable] - method << "rescue Exception => e" - method << "rescued_error = e" - method << "end" - end - - reverse_each do |callback| - method << callback.end(key, object) - end - - method << "raise rescued_error if rescued_error" if config[:rescuable] - method << "halted ? false : (block_given? ? value : true)" - method.compact.join("\n") - end - - def clone(klass) - chain = CallbackChain.new(@name, @config.dup) - callbacks = map { |c| c.clone(chain, klass) } - chain.push(*callbacks) - end - end - - module ClassMethods - # Make the _run_set_callback :save method. The generated method takes - # a block that it'll yield to. It'll call the before and around filters - # in order, yield the block, and then run the after filters. - # - # _run_set_callback :save do - # save - # end - # - # The _run_set_callback :save method can optionally take a key, which - # will be used to compile an optimized callback method for each - # key. See #define_callbacks for more information. - # - def __define_runner(symbol) #:nodoc: - body = send("_#{symbol}_callbacks").compile(nil) - - body, line = <<-RUBY_EVAL, __LINE__ - def _run_#{symbol}_callbacks(key = nil, &blk) - if key - name = "_run__\#{self.class.name.hash.abs}__#{symbol}__\#{key.hash.abs}__callbacks" - - unless respond_to?(name) - self.class.__create_keyed_callback(name, :#{symbol}, self, &blk) - end - - send(name, &blk) - else - #{body} - end - end - RUBY_EVAL - - silence_warnings do - undef_method "_run_#{symbol}_callbacks" if method_defined?("_run_#{symbol}_callbacks") - class_eval body, __FILE__, line - end - end - - # This is called the first time a callback is called with a particular - # key. It creates a new callback method for the key, calculating - # which callbacks can be omitted because of per_key conditions. - # - def __create_keyed_callback(name, kind, object, &blk) #:nodoc: - @_keyed_callbacks ||= {} - @_keyed_callbacks[name] ||= begin - str = send("_#{kind}_callbacks").compile(name, object) - class_eval "def #{name}() #{str} end", __FILE__, __LINE__ - true - end - end - - # This is used internally to append, prepend and skip callbacks to the - # CallbackChain. - # - def __update_callbacks(name, filters = [], block = nil) #:nodoc: - type = [:before, :after, :around].include?(filters.first) ? filters.shift : :before - options = filters.last.is_a?(Hash) ? filters.pop : {} - filters.unshift(block) if block - - chain = send("_#{name}_callbacks") - yield chain, type, filters, options if block_given? - - __define_runner(name) - end - - # Set callbacks for a previously defined callback. - # - # Syntax: - # set_callback :save, :before, :before_meth - # set_callback :save, :after, :after_meth, :if => :condition - # set_callback :save, :around, lambda { |r| stuff; yield; stuff } - # - # It also updates the _run_<name>_callbacks method, which is the public - # API to run the callbacks. Use skip_callback to skip any defined one. - # - # When creating or skipping callbacks, you can specify conditions that - # are always the same for a given key. For instance, in ActionPack, - # we convert :only and :except conditions into per-key conditions. - # - # before_filter :authenticate, :except => "index" - # becomes - # dispatch_callback :before, :authenticate, :per_key => {:unless => proc {|c| c.action_name == "index"}} - # - # Per-Key conditions are evaluated only once per use of a given key. - # In the case of the above example, you would do: - # - # _run_dispatch_callbacks(action_name) { ... dispatch stuff ... } - # - # In that case, each action_name would get its own compiled callback - # method that took into consideration the per_key conditions. This - # is a speed improvement for ActionPack. - # - def set_callback(name, *filters, &block) - __update_callbacks(name, filters, block) do |chain, type, filters, options| - filters.map! do |filter| - chain.delete_if {|c| c.matches?(type, filter) } - Callback.new(chain, filter, type, options.dup, self) - end - - options[:prepend] ? chain.unshift(*filters) : chain.push(*filters) - end - end - - # Skip a previously defined callback for a given type. - # - def skip_callback(name, *filters, &block) - __update_callbacks(name, filters, block) do |chain, type, filters, options| - chain = send("_#{name}_callbacks=", chain.clone(self)) - - filters.each do |filter| - filter = chain.find {|c| c.matches?(type, filter) } - - if filter && options.any? - filter.recompile!(options, options[:per_key] || {}) - else - chain.delete(filter) - end - end - end - end - - # Reset callbacks for a given type. - # - def reset_callbacks(symbol) - send("_#{symbol}_callbacks").clear - __define_runner(symbol) - end - - # Define callbacks types. - # - # ==== Example - # - # define_callbacks :validate - # - # ==== Options - # - # * <tt>:terminator</tt> - Indicates when a before filter is considered - # to be halted. - # - # define_callbacks :validate, :terminator => "result == false" - # - # In the example above, if any before validate callbacks returns false, - # other callbacks are not executed. Defaults to "false". - # - # * <tt>:rescuable</tt> - By default, after filters are not executed if - # the given block or an before_filter raises an error. Supply :rescuable => true - # to change this behavior. - # - # * <tt>:scope</tt> - Show which methods should be executed when a class - # is giben as callback: - # - # define_callbacks :filters, :scope => [ :kind ] - # - # When a class is given: - # - # before_filter MyFilter - # - # It will call the type of the filter in the given class, which in this - # case, is "before". - # - # If, for instance, you supply the given scope: - # - # define_callbacks :validate, :scope => [ :kind, :name ] - # - # It will call "#{kind}_#{name}" in the given class. So "before_validate" - # will be called in the class below: - # - # before_validate MyValidation - # - # Defaults to :kind. - # - def define_callbacks(*symbols) - config = symbols.last.is_a?(Hash) ? symbols.pop : {} - symbols.each do |symbol| - extlib_inheritable_accessor("_#{symbol}_callbacks") do - CallbackChain.new(symbol, config) - end - - __define_runner(symbol) - end - end - end - end -end |