mirror of
https://github.com/rails/rails.git
synced 2022-11-09 12:12:34 -05:00
a769fe9db1
This reverts commits911a0859ac
and30b31f51af
. Reason: these changes make the Active Model tests fail randomly. Some examples: http://travis-ci.org/#!/rails/rails/jobs/1498992 http://travis-ci.org/#!/rails/rails/jobs/1496948 http://travis-ci.org/#!/rails/rails/jobs/1489985 This script was used to reproduce these breaks: https://gist.github.com/f6828a03ee4d40bffbc3 200 times, 0 failures
532 lines
18 KiB
Ruby
532 lines
18 KiB
Ruby
require 'active_support/concern'
|
|
require 'active_support/descendants_tracker'
|
|
require 'active_support/core_ext/class/attribute'
|
|
require 'active_support/core_ext/kernel/reporting'
|
|
require 'active_support/core_ext/kernel/singleton_class'
|
|
require 'active_support/core_ext/object/inclusion'
|
|
|
|
module ActiveSupport
|
|
# \Callbacks are code hooks that are run at key points in an object's lifecycle.
|
|
# 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+), 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+).
|
|
#
|
|
# Three kinds of callbacks are supported: before callbacks, run before a certain event;
|
|
# after callbacks, run after the event; and around callbacks, blocks that surround the
|
|
# event, triggering it when they yield. Callback code can be contained in instance
|
|
# methods, procs or lambdas, or callback objects that respond to certain predetermined
|
|
# methods. See +ClassMethods.set_callback+ for details.
|
|
#
|
|
# class Record
|
|
# include ActiveSupport::Callbacks
|
|
# define_callbacks :save
|
|
#
|
|
# def save
|
|
# run_callbacks :save do
|
|
# puts "- save"
|
|
# end
|
|
# end
|
|
# end
|
|
#
|
|
# class PersonRecord < Record
|
|
# set_callback :save, :before, :saving_message
|
|
# def saving_message
|
|
# puts "saving..."
|
|
# end
|
|
#
|
|
# set_callback :save, :after do |object|
|
|
# puts "saved"
|
|
# end
|
|
# end
|
|
#
|
|
# person = PersonRecord.new
|
|
# person.save
|
|
#
|
|
# Output:
|
|
# saving...
|
|
# - save
|
|
# saved
|
|
module Callbacks
|
|
extend Concern
|
|
|
|
included do
|
|
extend ActiveSupport::DescendantsTracker
|
|
end
|
|
|
|
# Runs the callbacks for the given event.
|
|
#
|
|
# Calls the before and around callbacks in the order they were set, yields
|
|
# the block (if given one), and then runs the after callbacks in reverse order.
|
|
#
|
|
# If the callback chain was halted, returns +false+. Otherwise returns the result
|
|
# of the block, or +true+ if no block is given.
|
|
#
|
|
# run_callbacks :save do
|
|
# save
|
|
# end
|
|
def run_callbacks(kind, &block)
|
|
runner_name = self.class.__define_callbacks(kind, self)
|
|
send(runner_name, &block)
|
|
end
|
|
|
|
private
|
|
|
|
# A hook invoked everytime a before callback is halted.
|
|
# This can be overriden 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
|
|
|
|
def initialize(chain, filter, kind, options, klass)
|
|
@chain, @kind, @klass = chain, kind, klass
|
|
deprecate_per_key_option(options)
|
|
normalize_options!(options)
|
|
|
|
@raw_filter, @options = filter, options
|
|
@filter = _compile_filter(filter)
|
|
recompile_options!
|
|
end
|
|
|
|
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."
|
|
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
|
|
|
|
def normalize_options!(options)
|
|
options[:if] = Array(options[:if])
|
|
options[:unless] = Array(options[: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].concat(Array(new_options[:unless])) if new_options.key?(:unless)
|
|
filter_options[:unless].concat(Array(new_options[:if])) if new_options.key?(:if)
|
|
end
|
|
|
|
def recompile!(_options)
|
|
deprecate_per_key_option(_options)
|
|
_update_filter(self.options, _options)
|
|
|
|
recompile_options!
|
|
end
|
|
|
|
# Wraps code with filter
|
|
def apply(code)
|
|
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
|
|
when :after
|
|
<<-RUBY_EVAL
|
|
#{code}
|
|
if #{!chain.config[:skip_after_callbacks_if_terminated] || "!halted"} && #{@compiled_options}
|
|
#{@filter}
|
|
end
|
|
RUBY_EVAL
|
|
when :around
|
|
name = define_conditional_callback
|
|
<<-RUBY_EVAL
|
|
#{name}(halted) do
|
|
#{code}
|
|
value
|
|
end
|
|
RUBY_EVAL
|
|
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(" && ")
|
|
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(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.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
|
|
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 #:nodoc:#
|
|
attr_reader :name, :config
|
|
|
|
def initialize(name, config)
|
|
@name = name
|
|
@config = {
|
|
:terminator => "false",
|
|
:scope => [ :kind ]
|
|
}.merge(config)
|
|
end
|
|
|
|
def compile
|
|
method = []
|
|
method << "value = nil"
|
|
method << "halted = false"
|
|
|
|
callbacks = "value = !halted && (!block_given? || yield)"
|
|
reverse_each do |callback|
|
|
callbacks = callback.apply(callbacks)
|
|
end
|
|
method << callbacks
|
|
|
|
method << "value"
|
|
method.join("\n")
|
|
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(kind)
|
|
"_run__#{self.name.hash.abs}__#{kind}__callbacks"
|
|
end
|
|
|
|
# This is used internally to append, prepend and skip callbacks to the
|
|
# CallbackChain.
|
|
#
|
|
def __update_callbacks(name, filters = [], block = nil) #:nodoc:
|
|
type = filters.first.in?([:before, :after, :around]) ? filters.shift : :before
|
|
options = filters.last.is_a?(Hash) ? filters.pop : {}
|
|
filters.unshift(block) if block
|
|
|
|
([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)
|
|
end
|
|
end
|
|
|
|
# Install a callback for the given event.
|
|
#
|
|
# set_callback :save, :before, :before_meth
|
|
# set_callback :save, :after, :after_meth, :if => :condition
|
|
# set_callback :save, :around, lambda { |r| stuff; result = yield; stuff }
|
|
#
|
|
# The second arguments indicates whether the callback is to be run +:before+,
|
|
# +:after+, or +:around+ the event. If omitted, +:before+ is assumed. This
|
|
# means the first example above can also be written as:
|
|
#
|
|
# set_callback :save, :before_meth
|
|
#
|
|
# The callback can 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+.
|
|
#
|
|
# 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
|
|
# an argument.
|
|
#
|
|
# Before and around callbacks are called in the order that they are set; after
|
|
# callbacks are called in the reverse order.
|
|
#
|
|
# Around callbacks can access the return value from the event, if it
|
|
# wasn't halted, from the +yield+ call.
|
|
#
|
|
# ===== Options
|
|
#
|
|
# * <tt>:if</tt> - A symbol naming an instance method or a proc; the callback
|
|
# will be called only when it returns a true value.
|
|
# * <tt>:unless</tt> - A symbol naming an instance method or a proc; the callback
|
|
# will be called only when it returns a false value.
|
|
# * <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
|
|
|
|
filters.each do |filter|
|
|
chain.delete_if {|c| c.matches?(type, filter) }
|
|
end
|
|
|
|
options[:prepend] ? chain.unshift(*(mapped.reverse)) : chain.push(*mapped)
|
|
|
|
target.send("_#{name}_callbacks=", chain)
|
|
end
|
|
end
|
|
|
|
# Skip a previously set callback. Like +set_callback+, <tt>:if</tt> or <tt>:unless</tt>
|
|
# options may be passed in order to control when the callback is skipped.
|
|
#
|
|
# class Writer < Person
|
|
# skip_callback :validate, :before, :check_membership, :if => lambda { self.age > 18 }
|
|
# end
|
|
def skip_callback(name, *filter_list, &block)
|
|
__update_callbacks(name, filter_list, block) do |target, chain, type, filters, options|
|
|
filters.each do |filter|
|
|
filter = chain.find {|c| c.matches?(type, filter) }
|
|
|
|
if filter && options.any?
|
|
new_filter = filter.clone(chain, self)
|
|
chain.insert(chain.index(filter), new_filter)
|
|
new_filter.recompile!(options)
|
|
end
|
|
|
|
chain.delete(filter)
|
|
end
|
|
target.send("_#{name}_callbacks=", chain)
|
|
end
|
|
end
|
|
|
|
# Remove all set callbacks for the given event.
|
|
def reset_callbacks(symbol)
|
|
callbacks = send("_#{symbol}_callbacks")
|
|
|
|
ActiveSupport::DescendantsTracker.descendants(self).each do |target|
|
|
chain = target.send("_#{symbol}_callbacks").dup
|
|
callbacks.each { |c| chain.delete(c) }
|
|
target.send("_#{symbol}_callbacks=", chain)
|
|
target.__reset_runner(symbol)
|
|
end
|
|
|
|
self.send("_#{symbol}_callbacks=", callbacks.dup.clear)
|
|
|
|
__reset_runner(symbol)
|
|
end
|
|
|
|
# Define sets of events in the object lifecycle that support callbacks.
|
|
#
|
|
# define_callbacks :validate
|
|
# define_callbacks :initialize, :save, :destroy
|
|
#
|
|
# ===== Options
|
|
#
|
|
# * <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 <tt>result</tt> variable.
|
|
#
|
|
# define_callbacks :validate, :terminator => "result == false"
|
|
#
|
|
# In this example, if any before validate callbacks returns +false+,
|
|
# other callbacks are not executed. Defaults to "false", meaning no value
|
|
# halts the chain.
|
|
#
|
|
# * <tt>:skip_after_callbacks_if_terminated</tt> - Determines if after callbacks should be terminated
|
|
# by the <tt>:terminator</tt> option. By default after callbacks executed no matter
|
|
# if callback chain was terminated or not.
|
|
# Option makes sence only when <tt>:terminator</tt> option is specified.
|
|
#
|
|
# * <tt>:scope</tt> - Indicates which methods should be executed when an object
|
|
# is used as a callback.
|
|
#
|
|
# class Audit
|
|
# def before(caller)
|
|
# puts 'Audit: before is called'
|
|
# end
|
|
#
|
|
# def before_save(caller)
|
|
# puts 'Audit: before_save is called'
|
|
# end
|
|
# end
|
|
#
|
|
# class Account
|
|
# include ActiveSupport::Callbacks
|
|
#
|
|
# define_callbacks :save
|
|
# set_callback :save, :before, Audit.new
|
|
#
|
|
# def save
|
|
# run_callbacks :save do
|
|
# puts 'save in main'
|
|
# end
|
|
# end
|
|
# end
|
|
#
|
|
# In the above case whenever you save an account the method <tt>Audit#before</tt> will
|
|
# be called. On the other hand
|
|
#
|
|
# define_callbacks :save, :scope => [:kind, :name]
|
|
#
|
|
# would trigger <tt>Audit#before_save</tt> instead. That's constructed by calling
|
|
# <tt>#{kind}_#{name}</tt> on the given instance. In this case "kind" is "before" and
|
|
# "name" is "save". In this context +:kind+ and +:name+ have special meanings: +:kind+
|
|
# refers to the kind of callback (before/after/around) and +:name+ refers to the
|
|
# method on which callbacks are being defined.
|
|
#
|
|
# A declaration like
|
|
#
|
|
# 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))
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|