diff options
Diffstat (limited to 'activesupport/lib/active_support/callbacks.rb')
| -rw-r--r-- | activesupport/lib/active_support/callbacks.rb | 676 |
1 files changed, 423 insertions, 253 deletions
diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb index 6c0cae71ed..e14ece7f35 100644 --- a/activesupport/lib/active_support/callbacks.rb +++ b/activesupport/lib/active_support/callbacks.rb @@ -1,19 +1,20 @@ -require 'thread_safe' require 'active_support/concern' require 'active_support/descendants_tracker' +require 'active_support/core_ext/array/extract_options' require 'active_support/core_ext/class/attribute' require 'active_support/core_ext/kernel/reporting' require 'active_support/core_ext/kernel/singleton_class' +require 'thread' module ActiveSupport - # Callbacks are code hooks that are run at key points in an object's lifecycle. + # Callbacks are code hooks that are run at key points in an object's life cycle. # The typical use case is to have a base class define a set of callbacks # relevant to the other functionality it supplies, so that subclasses can # install callbacks that enhance or modify the base functionality without # needing to override or redefine methods of the base class. # # Mixing in this module allows you to define the events in the object's - # lifecycle that will support callbacks (via +ClassMethods.define_callbacks+), + # life cycle that will support callbacks (via +ClassMethods.define_callbacks+), # set the instance methods, procs, or callback objects to be called (via # +ClassMethods.set_callback+), and run the installed callbacks at the # appropriate times (via +run_callbacks+). @@ -61,6 +62,8 @@ module ActiveSupport extend ActiveSupport::DescendantsTracker end + CALLBACK_FILTER_TYPES = [:before, :after, :around] + # Runs the callbacks for the given event. # # Calls the before and around callbacks in the order they were set, yields @@ -74,171 +77,333 @@ module ActiveSupport # save # end def run_callbacks(kind, &block) - runner_name = self.class.__define_callbacks(kind, self) - send(runner_name, &block) + cbs = send("_#{kind}_callbacks") + if cbs.empty? + yield if block_given? + else + runner = cbs.compile + e = Filters::Environment.new(self, false, nil, block) + runner.call(e).value + end end private - # A hook invoked everytime a before callback is halted. + # A hook invoked every time a before callback is halted. # This can be overridden in AS::Callback implementors in order # to provide better debugging/logging. def halted_callback_hook(filter) end - class Callback #:nodoc:# - @@_callback_sequence = 0 - - attr_accessor :chain, :filter, :kind, :options, :klass, :raw_filter + module Conditionals # :nodoc: + class Value + def initialize(&block) + @block = block + end + def call(target, value); @block.call(value); end + end + end - def initialize(chain, filter, kind, options, klass) - @chain, @kind, @klass = chain, kind, klass - deprecate_per_key_option(options) - normalize_options!(options) + module Filters + Environment = Struct.new(:target, :halted, :value, :run_block) - @raw_filter, @options = filter, options - @filter = _compile_filter(filter) - recompile_options! + class End + def call(env) + block = env.run_block + env.value = !env.halted && (!block || block.call) + env + end end + ENDING = End.new + + class Before + def self.build(next_callback, user_callback, user_conditions, chain_config, filter) + halted_lambda = chain_config[:terminator] - def deprecate_per_key_option(options) - if options[:per_key] - raise NotImplementedError, ":per_key option is no longer supported. Use generic :if and :unless options instead." + if chain_config.key?(:terminator) && user_conditions.any? + halting_and_conditional(next_callback, user_callback, user_conditions, halted_lambda, filter) + elsif chain_config.key? :terminator + halting(next_callback, user_callback, halted_lambda, filter) + elsif user_conditions.any? + conditional(next_callback, user_callback, user_conditions) + else + simple next_callback, user_callback + end end - end - def clone(chain, klass) - obj = super() - obj.chain = chain - obj.klass = klass - obj.options = @options.dup - obj.options[:if] = @options[:if].dup - obj.options[:unless] = @options[:unless].dup - obj - end + private - def normalize_options!(options) - options[:if] = Array(options[:if]) - options[:unless] = Array(options[:unless]) + def self.halting_and_conditional(next_callback, user_callback, user_conditions, halted_lambda, filter) + lambda { |env| + target = env.target + value = env.value + halted = env.halted + + if !halted && user_conditions.all? { |c| c.call(target, value) } + result = user_callback.call target, value + env.halted = halted_lambda.call(target, result) + if env.halted + target.send :halted_callback_hook, filter + end + end + next_callback.call env + } + end + + def self.halting(next_callback, user_callback, halted_lambda, filter) + lambda { |env| + target = env.target + value = env.value + halted = env.halted + + unless halted + result = user_callback.call target, value + env.halted = halted_lambda.call(target, result) + if env.halted + target.send :halted_callback_hook, filter + end + end + next_callback.call env + } + end + + def self.conditional(next_callback, user_callback, user_conditions) + lambda { |env| + target = env.target + value = env.value + + if user_conditions.all? { |c| c.call(target, value) } + user_callback.call target, value + end + next_callback.call env + } + end + + def self.simple(next_callback, user_callback) + lambda { |env| + user_callback.call env.target, env.value + next_callback.call env + } + end end - def name - chain.name + class After + def self.build(next_callback, user_callback, user_conditions, chain_config) + if chain_config[:skip_after_callbacks_if_terminated] + if chain_config.key?(:terminator) && user_conditions.any? + halting_and_conditional(next_callback, user_callback, user_conditions) + elsif chain_config.key?(:terminator) + halting(next_callback, user_callback) + elsif user_conditions.any? + conditional next_callback, user_callback, user_conditions + else + simple next_callback, user_callback + end + else + if user_conditions.any? + conditional next_callback, user_callback, user_conditions + else + simple next_callback, user_callback + end + end + end + + private + + def self.halting_and_conditional(next_callback, user_callback, user_conditions) + lambda { |env| + env = next_callback.call env + target = env.target + value = env.value + halted = env.halted + + if !halted && user_conditions.all? { |c| c.call(target, value) } + user_callback.call target, value + end + env + } + end + + def self.halting(next_callback, user_callback) + lambda { |env| + env = next_callback.call env + unless env.halted + user_callback.call env.target, env.value + end + env + } + end + + def self.conditional(next_callback, user_callback, user_conditions) + lambda { |env| + env = next_callback.call env + target = env.target + value = env.value + + if user_conditions.all? { |c| c.call(target, value) } + user_callback.call target, value + end + env + } + end + + def self.simple(next_callback, user_callback) + lambda { |env| + env = next_callback.call env + user_callback.call env.target, env.value + env + } + end end - def next_id - @@_callback_sequence += 1 + class Around + def self.build(next_callback, user_callback, user_conditions, chain_config) + if chain_config.key?(:terminator) && user_conditions.any? + halting_and_conditional(next_callback, user_callback, user_conditions) + elsif chain_config.key? :terminator + halting(next_callback, user_callback) + elsif user_conditions.any? + conditional(next_callback, user_callback, user_conditions) + else + simple(next_callback, user_callback) + end + end + + private + + def self.halting_and_conditional(next_callback, user_callback, user_conditions) + lambda { |env| + target = env.target + value = env.value + halted = env.halted + + if !halted && user_conditions.all? { |c| c.call(target, value) } + user_callback.call(target, value) { + env = next_callback.call env + env.value + } + env + else + next_callback.call env + end + } + end + + def self.halting(next_callback, user_callback) + lambda { |env| + target = env.target + value = env.value + + unless env.halted + user_callback.call(target, value) { + env = next_callback.call env + env.value + } + env + else + next_callback.call env + end + } + end + + def self.conditional(next_callback, user_callback, user_conditions) + lambda { |env| + target = env.target + value = env.value + + if user_conditions.all? { |c| c.call(target, value) } + user_callback.call(target, value) { + env = next_callback.call env + env.value + } + env + else + next_callback.call env + end + } + end + + def self.simple(next_callback, user_callback) + lambda { |env| + user_callback.call(env.target, env.value) { + env = next_callback.call env + env.value + } + env + } + end end + end - def matches?(_kind, _filter) - @kind == _kind && @filter == _filter + class Callback #:nodoc:# + def self.build(chain, filter, kind, options) + new chain.name, filter, kind, options, chain.config end - def duplicates?(other) - matches?(other.kind, other.filter) + attr_accessor :kind, :name + attr_reader :chain_config + + def initialize(name, filter, kind, options, chain_config) + @chain_config = chain_config + @name = name + @kind = kind + @filter = filter + @key = compute_identifier filter + @if = Array(options[:if]) + @unless = Array(options[:unless]) end - def _update_filter(filter_options, new_options) - filter_options[:if].concat(Array(new_options[:unless])) if new_options.key?(:unless) - filter_options[:unless].concat(Array(new_options[:if])) if new_options.key?(:if) + def filter; @key; end + def raw_filter; @filter; end + + def merge(chain, new_options) + options = { + :if => @if.dup, + :unless => @unless.dup + } + + options[:if].concat Array(new_options.fetch(:unless, [])) + options[:unless].concat Array(new_options.fetch(:if, [])) + + self.class.build chain, @filter, @kind, options end - def recompile!(_options) - deprecate_per_key_option(_options) - _update_filter(self.options, _options) + def matches?(_kind, _filter) + @kind == _kind && filter == _filter + end - recompile_options! + def duplicates?(other) + case @filter + when Symbol, String + matches?(other.kind, other.filter) + else + false + end end # Wraps code with filter - def apply(code) - case @kind + def apply(next_callback) + user_conditions = conditions_lambdas + user_callback = make_lambda @filter + + case kind when :before - <<-RUBY_EVAL - if !halted && #{@compiled_options} - # This double assignment is to prevent warnings in 1.9.3 as - # the `result` variable is not always used except if the - # terminator code refers to it. - result = result = #{@filter} - halted = (#{chain.config[:terminator]}) - if halted - halted_callback_hook(#{@raw_filter.inspect.inspect}) - end - end - #{code} - RUBY_EVAL + Filters::Before.build(next_callback, user_callback, user_conditions, chain_config, @filter) when :after - <<-RUBY_EVAL - #{code} - if #{!chain.config[:skip_after_callbacks_if_terminated] || "!halted"} && #{@compiled_options} - #{@filter} - end - RUBY_EVAL + Filters::After.build(next_callback, user_callback, user_conditions, chain_config) when :around - name = define_conditional_callback - <<-RUBY_EVAL - #{name}(halted) do - #{code} - value - end - RUBY_EVAL + Filters::Around.build(next_callback, user_callback, user_conditions, chain_config) end end private - # Compile around filters with conditions into proxy methods - # that contain the conditions. - # - # For `set_callback :save, :around, :filter_name, if: :condition': - # - # def _conditional_callback_save_17 - # if condition - # filter_name do - # yield self - # end - # else - # yield self - # end - # end - def define_conditional_callback - name = "_conditional_callback_#{@kind}_#{next_id}" - @klass.class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 - def #{name}(halted) - if #{@compiled_options} && !halted - #{@filter} do - yield self - end - else - yield self - end - end - RUBY_EVAL - name - end - - # 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 recompile_options! - conditions = ["true"] - - unless options[:if].empty? - conditions << Array(_compile_filter(options[:if])) - end - - unless options[:unless].empty? - conditions << Array(_compile_filter(options[:unless])).map {|f| "!#{f}"} - end - - @compiled_options = conditions.flatten.join(" && ") + def invert_lambda(l) + lambda { |*args, &blk| !l.call(*args, &blk) } 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. @@ -247,90 +412,106 @@ module ActiveSupport # 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. + # Strings:: class_eval'd into methods. + # Procs:: using define_method compiled into methods. # Objects:: # a method is created that calls the before_foo method # on the object. - def _compile_filter(filter) + def make_lambda(filter) case filter - when Array - filter.map {|f| _compile_filter(f)} when Symbol - filter + lambda { |target, _, &blk| target.send filter, &blk } when String - "(#{filter})" - when Proc - method_name = "_callback_#{@kind}_#{next_id}" - @klass.send(:define_method, method_name, &filter) - return method_name if filter.arity <= 0 + l = eval "lambda { |value| #{filter} }" + lambda { |target, value| target.instance_exec(value, &l) } + when Conditionals::Value then filter + when ::Proc + if filter.arity > 1 + return lambda { |target, _, &block| + raise ArgumentError unless block + target.instance_exec(target, block, &filter) + } + end - method_name << (filter.arity == 1 ? "(self)" : " self, Proc.new ") + if filter.arity <= 0 + lambda { |target, _| target.instance_exec(&filter) } + else + lambda { |target, _| target.instance_exec(target, &filter) } + end else - method_name = "_callback_#{@kind}_#{next_id}" - @klass.send(:define_method, "#{method_name}_object") { filter } - - _normalize_legacy_filter(kind, filter) - scopes = Array(chain.config[:scope]) - method_to_call = scopes.map{ |s| s.is_a?(Symbol) ? send(s) : s }.join("_") + scopes = Array(chain_config[:scope]) + method_to_call = scopes.map{ |s| public_send(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 + lambda { |target, _, &blk| + filter.public_send method_to_call, target, &blk + } end end - def _normalize_legacy_filter(kind, filter) - if !filter.respond_to?(kind) && filter.respond_to?(:filter) - message = "Filter object with #filter method is deprecated. Define method corresponding " \ - "to filter type (#before, #after or #around)." - ActiveSupport::Deprecation.warn message - filter.singleton_class.class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 - def #{kind}(context, &block) filter(context, &block) end - RUBY_EVAL - elsif filter.respond_to?(:before) && filter.respond_to?(:after) && kind == :around && !filter.respond_to?(:around) - message = "Filter object with #before and #after methods is deprecated. Define #around method instead." - ActiveSupport::Deprecation.warn message - def filter.around(context) - should_continue = before(context) - yield if should_continue - after(context) - end + def compute_identifier(filter) + case filter + when String, ::Proc + filter.object_id + else + filter end end + + def conditions_lambdas + @if.map { |c| make_lambda c } + + @unless.map { |c| invert_lambda make_lambda c } + end end # An Array with a compile method. - class CallbackChain < Array #:nodoc:# + class CallbackChain #:nodoc:# + include Enumerable + attr_reader :name, :config def initialize(name, config) @name = name @config = { - :terminator => "false", :scope => [ :kind ] }.merge!(config) + @chain = [] + @callbacks = nil + @mutex = Mutex.new end - def compile - method = [] - method << "value = nil" - method << "halted = false" + def each(&block); @chain.each(&block); end + def index(o); @chain.index(o); end + def empty?; @chain.empty?; end - callbacks = "value = !halted && (!block_given? || yield)" - reverse_each do |callback| - callbacks = callback.apply(callbacks) - end - method << callbacks + def insert(index, o) + @callbacks = nil + @chain.insert(index, o) + end + + def delete(o) + @callbacks = nil + @chain.delete(o) + end + + def clear + @callbacks = nil + @chain.clear + self + end - method << "value" - method.join("\n") + def initialize_copy(other) + @callbacks = nil + @chain = other.chain.dup + @mutex = Mutex.new + end + + def compile + @callbacks || @mutex.synchronize do + @callbacks ||= @chain.reverse.inject(Filters::ENDING) do |chain, callback| + callback.apply chain + end + end end def append(*callbacks) @@ -341,69 +522,43 @@ module ActiveSupport callbacks.each { |c| prepend_one(c) } end + protected + def chain; @chain; end + private def append_one(callback) + @callbacks = nil remove_duplicates(callback) - push(callback) + @chain.push(callback) end def prepend_one(callback) + @callbacks = nil remove_duplicates(callback) - unshift(callback) + @chain.unshift(callback) end def remove_duplicates(callback) - delete_if { |c| callback.duplicates?(c) } + @callbacks = nil + @chain.delete_if { |c| callback.duplicates?(c) } end - end module ClassMethods - - # This method defines callback chain method for the given kind - # if it was not yet defined. - # This generated method plays caching role. - def __define_callbacks(kind, object) #:nodoc: - name = __callback_runner_name(kind) - unless object.respond_to?(name, true) - str = object.send("_#{kind}_callbacks").compile - class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 - def #{name}() #{str} end - protected :#{name} - RUBY_EVAL - end - name - end - - def __reset_runner(symbol) - name = __callback_runner_name(symbol) - undef_method(name) if method_defined?(name) - end - - def __callback_runner_name_cache - @__callback_runner_name_cache ||= ThreadSafe::Cache.new {|cache, kind| cache[kind] = __generate_callback_runner_name(kind) } - end - - def __generate_callback_runner_name(kind) - "_run__#{self.name.hash.abs}__#{kind}__callbacks" - end - - def __callback_runner_name(kind) - __callback_runner_name_cache[kind] + def normalize_callback_params(filters, block) # :nodoc: + type = CALLBACK_FILTER_TYPES.include?(filters.first) ? filters.shift : :before + options = filters.extract_options! + filters.unshift(block) if block + [type, filters, options.dup] 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 - + def __update_callbacks(name) #:nodoc: ([self] + ActiveSupport::DescendantsTracker.descendants(self)).reverse.each do |target| - chain = target.send("_#{name}_callbacks") - yield target, chain.dup, type, filters, options - target.__reset_runner(name) + chain = target.get_callbacks name + yield target, chain.dup end end @@ -419,10 +574,10 @@ module ActiveSupport # # set_callback :save, :before_meth # - # The callback can specified as a symbol naming an instance method; as a + # The callback can be specified as a symbol naming an instance method; as a # proc, lambda, or block; as a string to be instance evaluated; or as an # object that responds to a certain method determined by the <tt>:scope</tt> - # argument to +define_callback+. + # argument to +define_callbacks+. # # If a proc, lambda, or block is given, its body is evaluated in the context # of the current object. It can also optionally accept the current object as @@ -443,16 +598,15 @@ module ActiveSupport # * <tt>:prepend</tt> - If +true+, the callback will be prepended to the # existing chain rather than appended. def set_callback(name, *filter_list, &block) - mapped = nil - - __update_callbacks(name, filter_list, block) do |target, chain, type, filters, options| - mapped ||= filters.map do |filter| - Callback.new(chain, filter, type, options.dup, self) - end + type, filters, options = normalize_callback_params(filter_list, block) + self_chain = get_callbacks name + mapped = filters.map do |filter| + Callback.build(self_chain, filter, type, options) + end + __update_callbacks(name) do |target, chain| options[:prepend] ? chain.prepend(*mapped) : chain.append(*mapped) - - target.send("_#{name}_callbacks=", chain) + target.set_callbacks name, chain end end @@ -464,39 +618,37 @@ module ActiveSupport # skip_callback :validate, :before, :check_membership, if: -> { self.age > 18 } # end def skip_callback(name, *filter_list, &block) - __update_callbacks(name, filter_list, block) do |target, chain, type, filters, options| + type, filters, options = normalize_callback_params(filter_list, block) + + __update_callbacks(name) do |target, chain| filters.each do |filter| filter = chain.find {|c| c.matches?(type, filter) } if filter && options.any? - new_filter = filter.clone(chain, self) + new_filter = filter.merge(chain, options) chain.insert(chain.index(filter), new_filter) - new_filter.recompile!(options) end chain.delete(filter) end - target.send("_#{name}_callbacks=", chain) + target.set_callbacks name, chain end end # Remove all set callbacks for the given event. - def reset_callbacks(symbol) - callbacks = send("_#{symbol}_callbacks") + def reset_callbacks(name) + callbacks = get_callbacks name ActiveSupport::DescendantsTracker.descendants(self).each do |target| - chain = target.send("_#{symbol}_callbacks").dup + chain = target.get_callbacks(name).dup callbacks.each { |c| chain.delete(c) } - target.send("_#{symbol}_callbacks=", chain) - target.__reset_runner(symbol) + target.set_callbacks name, chain end - self.send("_#{symbol}_callbacks=", callbacks.dup.clear) - - __reset_runner(symbol) + self.set_callbacks name, callbacks.dup.clear end - # Define sets of events in the object lifecycle that support callbacks. + # Define sets of events in the object life cycle that support callbacks. # # define_callbacks :validate # define_callbacks :initialize, :save, :destroy @@ -505,10 +657,11 @@ module ActiveSupport # # * <tt>:terminator</tt> - Determines when a before filter will halt the # callback chain, preventing following callbacks from being called and - # the event from being triggered. This is a string to be eval'ed. The - # result of the callback is available in the +result+ variable. + # the event from being triggered. This should be a lambda to be executed. + # The current object and the return result of the callback will be called + # with the lambda. # - # define_callbacks :validate, terminator: 'result == false' + # define_callbacks :validate, terminator: ->(target, result) { result == false } # # In this example, if any before validate callbacks returns +false+, # other callbacks are not executed. Defaults to +false+, meaning no value @@ -563,13 +716,30 @@ module ActiveSupport # define_callbacks :save, scope: [:name] # # would call <tt>Audit#save</tt>. - def define_callbacks(*callbacks) - config = callbacks.last.is_a?(Hash) ? callbacks.pop : {} - callbacks.each do |callback| - class_attribute "_#{callback}_callbacks" - send("_#{callback}_callbacks=", CallbackChain.new(callback, config)) + def define_callbacks(*names) + options = names.extract_options! + if options.key?(:terminator) && String === options[:terminator] + ActiveSupport::Deprecation.warn "String based terminators are deprecated, please use a lambda" + value = options[:terminator] + line = class_eval "lambda { |result| #{value} }", __FILE__, __LINE__ + options[:terminator] = lambda { |target, result| target.instance_exec(result, &line) } + end + + names.each do |name| + class_attribute "_#{name}_callbacks" + set_callbacks name, CallbackChain.new(name, options) end end + + protected + + def get_callbacks(name) + send "_#{name}_callbacks" + end + + def set_callbacks(name, callbacks) + send "_#{name}_callbacks=", callbacks + end end end end |