Implement custom element reactions #17614

cbrewster · 2017-07-05T22:18:48Z

Initial work for implementing custom element reactions: https://html.spec.whatwg.org/multipage/custom-elements.html#custom-element-reactions

./mach build -d does not report any errors
./mach test-tidy does not report any errors
These changes fix #17433 (github issue number if applicable).

There are tests for these changes OR
These changes do not require tests because _____

This change is

highfive · 2017-07-05T22:18:52Z

Heads up! This PR modifies the following files:

@fitzgen: components/script/dom/customelementregistry.rs, components/script/dom/webidls/CustomElementRegistry.webidl, components/script/dom/element.rs, components/script/dom/bindings/codegen/CodegenRust.py, components/script/dom/create.rs and 5 more
@KiChjang: components/script/dom/customelementregistry.rs, components/script/dom/webidls/CustomElementRegistry.webidl, components/script/dom/element.rs, components/script/dom/bindings/codegen/CodegenRust.py, components/script/dom/create.rs and 5 more

highfive · 2017-07-05T22:18:53Z

Warning

These commits modify unsafe code. Please review it carefully!

jdm · 2017-07-06T02:26:52Z

failures:

    size_of::size_div

    size_of::size_element

    size_of::size_htmlelement

    size_of::size_span

cbrewster · 2017-07-07T21:20:37Z

Ready for review. r? @jdm

I am going to submit the changes for [CEReactions] as a separate PR since it would add quite a lot of noise here. This means that all reactions are triggered via the backup element queue through a microtask. This is why many reaction-related tests are failing, they should be passing after [CEReactions] is implemented.

nox · 2017-07-11T11:40:02Z

The unit tests are still failing.

bors-servo · 2017-07-12T00:30:08Z

☔ The latest upstream changes (presumably #17364) made this pull request unmergeable. Please resolve the merge conflicts.

jdm · 2017-07-12T16:24:17Z

components/script/dom/bindings/trace.rs

@@ -221,6 +221,15 @@ unsafe impl<T: JSTraceable> JSTraceable for Vec<T> {
    }
 }

+unsafe impl<T: JSTraceable> JSTraceable for [T] {


This commit can be removed now.

jdm · 2017-07-12T16:24:17Z

components/script/dom/customelementregistry.rs

+    /// Steps 10.3, 10.4
+    #[allow(unsafe_code)]
+    fn get_callbacks(&self, prototype: HandleObject) -> Fallible<LifecycleCallbacks> {
+        macro_rules! get_callback {


This can be a function that returns Result<Function, Error>, right? I don't see a reason to use a macro here.

jdm · 2017-07-12T16:24:17Z

components/script/dom/customelementregistry.rs

+            },
+            _ => return Err(Error::JSFailed),
+        };
+        Ok(observed_attributes)


We can return this expression directly:

match conversion { Ok(ConversionResult::Success(attributes)) => Ok(attributes), Ok(ConversionResult::Failure(error)) => Err(Error::Type(error)), Err(()) => Err(Error::JSFailed), }

jdm · 2017-07-12T16:24:17Z

components/script/dom/attr.rs

        MutationObserver::queue_a_mutation_record(owner.upcast::<Node>(), mutation);

+        let reaction = CallbackReaction::AttributeChanged(name, Some(old_value), Some(new_value), namespace);
+        ScriptThread::enqueue_callback_reaction(self.owner().unwrap(), reaction);


Use owner instead of self.owner().

jdm · 2017-07-12T16:24:17Z

components/script/dom/customelementregistry.rs

@@ -456,6 +456,196 @@ impl CustomElementDefinition {
    }
 }

+#[derive(HeapSizeOf, JSTraceable)]
+pub enum CustomElementReaction {


Add #[must_root] to this.

jdm · 2017-07-12T16:24:17Z

components/script/dom/customelementregistry.rs

+    fn invoke_reactions(&self) {
+        // Steps 1-2
+        for element in self.queue.borrow().iter() {
+            element.invoke_reactions()


Can these reactions end up appending an element to this queue?

I do not believe so, there are two queues an element can be added to:

The current element queue.

The backup element queue.

For the first case, the current element queue is popped from the custom element reaction stack thus it is no longer the current element queue which means no element will be added to it.

The second case is the backup element queue has the processing_backup_element_queue flag which prevents elements being enqueued until the flag is set to NotProcessing.

Oh actually in the second case, an element can be appended to the backup element queue is being invoked. The flag check occurs after the element is appended to the queue. This is what causes the crash in the test expectations.

I want to change it so the queue is not borrowed for the duration of the loop. Instead if element are popped and processed, new element can be appended to the queue. But I always run into unrooted must root errors. any ideas?

while let Some(element) = self.queue.borrow_mut().pop_front().map(|e| Root::from_ref(&*e)) { element.invoke_reactions() }

Avoiding the closure appears to appease the lint

self.queue.borrow_mut().pop_front().as_ref().map(JS::deref).map(Root::from_ref)

jdm · 2017-07-12T16:24:17Z

components/script/dom/element.rs

+    pub fn invoke_reactions(&self) {
+        let mut reaction_queue = self.custom_element_reaction_queue.borrow_mut();
+        while let Some(reaction) = reaction_queue.pop_front() {
+            reaction.invoke(Root::from_ref(self));


Can these reactions end up appending reactions to the queue?

See other comment

jdm · 2017-07-12T16:24:17Z

components/script/dom/node.rs

@@ -313,6 +315,11 @@ impl Node {
            // e.g. when removing a <form>.
            vtable_for(&&*node).unbind_from_tree(&context);
            node.style_and_layout_data.get().map(|d| node.dispose(d));
+            if let Some(element) = node.downcast::<Element>() {


Add a link to https://dom.spec.whatwg.org/#concept-node-remove step 14 here.

jdm · 2017-07-12T16:24:17Z

components/script/dom/node.rs

            for descendant in node.traverse_preorder() {
+                // Step 3.2.
+                if let Some(element) = node.downcast::<Element>() {
+                    if element.get_custom_element_definition().is_some() {


We may want to write a Node::as_custom_element helper which combines the downcast and custom check into one.

jdm · 2017-07-12T16:24:17Z

tests/wpt/metadata/custom-elements/reaction-timing.html.ini

@@ -1,5 +1,6 @@
 [reaction-timing.html]
  type: testharness
+  expected: CRASH



        Store lifecycle callbacks when CEs are defined

This implements steps 10.3 - 10.4 of the CustomElementRegistry.define steps.


        Get observed attributes when a CE is defined

Implements steps 10.5 - 10.6 of CustomElementRegistry.define

jdm · 2017-07-17T23:24:56Z

components/script/dom/customelementregistry.rs

+        while let Some(element) = self.next_element() {
+            element.invoke_reactions()
+        }
+        self.queue.borrow_mut().clear();


This shouldn't be necessary since we now pop, right?

jdm · 2017-07-17T23:25:55Z

Looks like the sizeof unit tests are failing again, too.


        Support custom element callback reactions


        Invoke backup element queue via a microtask

cbrewster · 2017-07-18T04:24:20Z

@bors-servo r=jdm

bors-servo · 2017-07-18T04:24:21Z

📌 Commit 9b587a4 has been approved by jdm

bors-servo · 2017-07-18T05:58:55Z

⌛ Testing commit 9b587a4 with merge 7b13444...


        Auto merge of #17614 - cbrewster:custom_element_reactions, r=jdm

Implement custom element reactions  Initial work for implementing custom element reactions: https://html.spec.whatwg.org/multipage/custom-elements.html#custom-element-reactions ---  - [X] `./mach build -d` does not report any errors - [X] `./mach test-tidy` does not report any errors - [X] These changes fix #17433 (github issue number if applicable).  - [X] There are tests for these changes OR - [ ] These changes do not require tests because _____    --- This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/17614)

bors-servo · 2017-07-18T07:03:58Z

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel-css, linux-rel-wpt, mac-dev-unit, mac-rel-css1, mac-rel-css2, mac-rel-wpt1, mac-rel-wpt2, mac-rel-wpt3, mac-rel-wpt4, windows-msvc-dev
Approved by: jdm
Pushing 7b13444 to master...


        Auto merge of #17761 - cbrewster:ce_reactions, r=jdm

Add [CEReactions] to webidls  Relies on #17614 ---  - [X] `./mach build -d` does not report any errors - [X] `./mach test-tidy` does not report any errors - [ ] These changes fix #__ (github issue number if applicable).  - [X] There are tests for these changes OR - [ ] These changes do not require tests because _____    --- This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/17761)


        Auto merge of #17761 - cbrewster:ce_reactions, r=jdm

Add [CEReactions] to webidls  Relies on #17614 ---  - [X] `./mach build -d` does not report any errors - [X] `./mach test-tidy` does not report any errors - [ ] These changes fix #__ (github issue number if applicable).  - [X] There are tests for these changes OR - [ ] These changes do not require tests because _____    --- This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/17761)

highfive assigned jdm Jul 5, 2017

highfive added the S-awaiting-review label Jul 5, 2017

jdm added the S-fails-travis label Jul 6, 2017

cbrewster force-pushed the cbrewster:custom_element_reactions branch from 63015e5 to 787111d Jul 6, 2017

jdm removed the S-fails-travis label Jul 6, 2017

cbrewster force-pushed the cbrewster:custom_element_reactions branch 2 times, most recently from c9efe47 to 20c8a58 Jul 7, 2017

cbrewster changed the title ~~[WIP] Implement custom element reactions~~ Implement custom element reactions Jul 7, 2017

cbrewster force-pushed the cbrewster:custom_element_reactions branch from 3b21819 to b2b5f06 Jul 10, 2017

nox added the S-fails-travis label Jul 11, 2017

cbrewster force-pushed the cbrewster:custom_element_reactions branch from b2b5f06 to 944ca90 Jul 11, 2017

cbrewster removed the S-fails-travis label Jul 11, 2017

highfive added the S-needs-rebase label Jul 12, 2017

jdm requested changes Jul 12, 2017

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jdm added S-needs-code-changes and removed S-awaiting-review labels Jul 12, 2017

cbrewster added 2 commits Jun 19, 2017

Store lifecycle callbacks when CEs are defined

901a202

This implements steps 10.3 - 10.4 of the CustomElementRegistry.define steps.

Get observed attributes when a CE is defined

596ed55

Implements steps 10.5 - 10.6 of CustomElementRegistry.define

cbrewster force-pushed the cbrewster:custom_element_reactions branch from 944ca90 to 30afac6 Jul 17, 2017

highfive added S-awaiting-review and removed S-needs-code-changes labels Jul 17, 2017

cbrewster force-pushed the cbrewster:custom_element_reactions branch from 30afac6 to 348251b Jul 17, 2017

cbrewster mentioned this pull request Jul 17, 2017

Add [CEReactions] to webidls #17761

Merged

3 of 5 tasks complete

jdm approved these changes Jul 17, 2017

View changes

components/script/dom/customelementregistry.rs

while let Some(element) = self.next_element() {

element.invoke_reactions()

}

self.queue.borrow_mut().clear();

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jdm Jul 17, 2017
Member

This shouldn't be necessary since we now pop, right?

jdm added S-tests-failed and removed S-awaiting-review labels Jul 17, 2017

cbrewster added 2 commits Jun 21, 2017

Support custom element callback reactions

4665991

Invoke backup element queue via a microtask

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9b587a4

cbrewster force-pushed the cbrewster:custom_element_reactions branch from 348251b to 9b587a4 Jul 18, 2017

highfive added S-awaiting-review and removed S-tests-failed labels Jul 18, 2017

highfive added S-awaiting-merge and removed S-awaiting-review S-needs-rebase labels Jul 18, 2017

bors-servo merged commit 9b587a4 into servo:master Jul 18, 2017
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servo / servo

Implement custom element reactions #17614

Implement custom element reactions #17614

cbrewster commented Jul 5, 2017 •

edited

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jdm commented Jul 17, 2017

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bors-servo commented Jul 18, 2017

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Implement custom element reactions #17614

Implement custom element reactions #17614

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jdm commented Jul 17, 2017

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cbrewster commented Jul 5, 2017 •

edited