aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAlberto Almagro <alberto.almagro@rakuten.com>2017-08-03 22:07:32 +0200
committerAlberto Almagro <alberto.almagro@rakuten.com>2017-08-14 23:56:12 +0200
commit10bf93ef92a70ae511036134290bf0e2de184b5c (patch)
tree839f02fe2096a6412448aaf747b393c5ee02502f
parent1e73c1d4f74bcca05f4691465e8482cce8a3fdb9 (diff)
downloadrails-10bf93ef92a70ae511036134290bf0e2de184b5c.tar.gz
rails-10bf93ef92a70ae511036134290bf0e2de184b5c.tar.bz2
rails-10bf93ef92a70ae511036134290bf0e2de184b5c.zip
Allow lazy load hooks to be executed only once
Provide run_once: true option to on_load in case you want a hook only to be executed once. This may be useful in cases where executing a hook several times may have undesired side effects
-rw-r--r--activesupport/lib/active_support/lazy_load_hooks.rb34
-rw-r--r--activesupport/test/lazy_load_hooks_test.rb37
2 files changed, 63 insertions, 8 deletions
diff --git a/activesupport/lib/active_support/lazy_load_hooks.rb b/activesupport/lib/active_support/lazy_load_hooks.rb
index c23b319046..c124416595 100644
--- a/activesupport/lib/active_support/lazy_load_hooks.rb
+++ b/activesupport/lib/active_support/lazy_load_hooks.rb
@@ -27,11 +27,17 @@ module ActiveSupport
base.class_eval do
@load_hooks = Hash.new { |h, k| h[k] = [] }
@loaded = Hash.new { |h, k| h[k] = [] }
+ @run_once = Hash.new { |h, k| h[k] = [] }
end
end
# Declares a block that will be executed when a Rails component is fully
# loaded.
+ #
+ # Options:
+ #
+ # * <tt>:yield</tt> - Yields the object that run_load_hooks to +block+.
+ # * <tt>:run_once</tt> - Given +block+ will run only once.
def on_load(name, options = {}, &block)
@loaded[name].each do |base|
execute_hook(base, options, block)
@@ -40,20 +46,32 @@ module ActiveSupport
@load_hooks[name] << [block, options]
end
- def execute_hook(base, options, block)
- if options[:yield]
- block.call(base)
- else
- base.instance_eval(&block)
- end
- end
-
def run_load_hooks(name, base = Object)
@loaded[name] << base
@load_hooks[name].each do |hook, options|
execute_hook(base, options, hook)
end
end
+
+ private
+
+ def with_execution_control(name, block, once)
+ unless @run_once[name].include?(block)
+ @run_once[name] << block if once
+
+ yield
+ end
+ end
+
+ def execute_hook(base, options, block)
+ with_execution_control(name, block, options[:run_once]) do
+ if options[:yield]
+ block.call(base)
+ else
+ base.instance_eval(&block)
+ end
+ end
+ end
end
extend LazyLoadHooks
diff --git a/activesupport/test/lazy_load_hooks_test.rb b/activesupport/test/lazy_load_hooks_test.rb
index 9c9264e8fc..c161005100 100644
--- a/activesupport/test/lazy_load_hooks_test.rb
+++ b/activesupport/test/lazy_load_hooks_test.rb
@@ -20,6 +20,18 @@ class LazyLoadHooksTest < ActiveSupport::TestCase
assert_equal 7, i
end
+ def test_basic_hook_with_two_registrations_only_once
+ i = 0
+ ActiveSupport.on_load(:basic_hook_with_two_once, run_once: true) do
+ i += incr
+ end
+ assert_equal 0, i
+ ActiveSupport.run_load_hooks(:basic_hook_with_two_once, FakeContext.new(2))
+ assert_equal 2, i
+ ActiveSupport.run_load_hooks(:basic_hook_with_two_once, FakeContext.new(5))
+ assert_equal 2, i
+ end
+
def test_hook_registered_after_run
i = 0
ActiveSupport.run_load_hooks(:registered_after)
@@ -37,6 +49,15 @@ class LazyLoadHooksTest < ActiveSupport::TestCase
assert_equal 7, i
end
+ def test_hook_registered_after_run_with_two_registrations_only_once
+ i = 0
+ ActiveSupport.run_load_hooks(:registered_after_with_two_once, FakeContext.new(2))
+ ActiveSupport.run_load_hooks(:registered_after_with_two_once, FakeContext.new(5))
+ assert_equal 0, i
+ ActiveSupport.on_load(:registered_after_with_two_once, run_once: true) { i += incr }
+ assert_equal 2, i
+ end
+
def test_hook_registered_interleaved_run_with_two_registrations
i = 0
ActiveSupport.run_load_hooks(:registered_interleaved_with_two, FakeContext.new(2))
@@ -47,6 +68,22 @@ class LazyLoadHooksTest < ActiveSupport::TestCase
assert_equal 7, i
end
+ def test_hook_registered_interleaved_run_with_two_registrations_once
+ i = 0
+ ActiveSupport
+ .run_load_hooks(:registered_interleaved_with_two_once, FakeContext.new(2))
+ assert_equal 0, i
+
+ ActiveSupport.on_load(:registered_interleaved_with_two_once, run_once: true) do
+ i += incr
+ end
+ assert_equal 2, i
+
+ ActiveSupport
+ .run_load_hooks(:registered_interleaved_with_two_once, FakeContext.new(5))
+ assert_equal 2, i
+ end
+
def test_hook_receives_a_context
i = 0
ActiveSupport.on_load(:contextual) { i += incr }