зеркало из https://github.com/mozilla/gecko-dev.git
a07852b3fc
The fix for [Bug 1557689](https://bugzilla.mozilla.org/show_bug.cgi?id=1557689) created a situation in the [`Rule.onDeclarationsChanged()`](https://searchfox.org/mozilla-central/rev/6566d92dd46417a2f57e75c515135ebe84c9cef5/devtools/client/inspector/rules/models/rule.js#869-887) whereby the `isUsed` state of client-side declarations was made to point to a fixed `isUsed` state received from the server, thus losing sync with the latest state of the `StyleRuleActor`. Until another "declarations-update" event was fired from the `StyleRuleActor`, the rule's declarations' `isUsed` flag would point to the state with which they were overwritten on the last event handler call. As a reminder, the root cause of [Bug 1557689](https://bugzilla.mozilla.org/show_bug.cgi?id=1557689) was the inability force a "refresh" of the `StyleRuleFront` so it picked-up the latest `isUsed` state for its declarations when they depend on other declarations from other rules (ex: `justify-content: center` depends on `display:flex`). Therefore, the "declarations-updated" event was introduced with a payload of changed declarations to overwrite the client-side ones. It was convoluted, but it worked. However, while investigating the cause of this newer bug [Bug 1593944](https://bugzilla.mozilla.org/show_bug.cgi?id=1593944), I discovered an unusual but perhaps expected side-effect: when dispatching an event over the protocol with a payload of the `StyleRuleActor`, its corresponding `StyleRuleFront` on the client would "refresh" automatically (meaning that, looking up state on the previous front reference would point to the latest state from the actor) . The client doesn't even need to use this payload to replace its previous front reference. Surprisingly, the client doesn't even need to explicitly listen to the event which carries the `StyleRuleActor`/`StyleRuleFront` reference. So long as a previous reference of the front exists on the client, it will point to the updated state of the actor. I haven't been able to identify whether this is a known and expected behavior, so I'm pinging @jdescottes and @ochameau to weigh in on the validity of these findings. Relying on this behavior, the fix for both [Bug 1557689](https://bugzilla.mozilla.org/show_bug.cgi?id=1557689) and [Bug 1557689](https://bugzilla.mozilla.org/show_bug.cgi?id=1557689) involves simply emitting an event, "rule-updated", with the `StyleRuleActor` instance as payload whenever its internal state changes meaningfully so the corresponding front updates. The client will pick-up the latest `isUsed` state of declarations from its reference to the `StyleRuleFront`. --- Another way to check this behavior and hypothesis is to do the following: - In [`StyleRuleActor.setRuleText()`](https://searchfox.org/mozilla-central/rev/6566d92dd46417a2f57e75c515135ebe84c9cef5/devtools/server/actors/styles.js#1704) replace `return this` with `return null`; (this will no longer return the `StyleRuleActor` over the protocol; it's not explicitly used on the client anyway). - In the spec, replace the [`setRuleText()`](https://searchfox.org/mozilla-central/rev/6566d92dd46417a2f57e75c515135ebe84c9cef5/devtools/shared/specs/styles.js#222) return value with `RetVal("nullable:domstylerule")` so the protocol doesn't throw an error when getting the `null` from the actor. - Make a build. - Then, open the Inspector -> Rules View and change the value of a valid declaration, say: `display: block`, to something invalid, like `display: booo`. Notice that the declaration is no longer marked invalid with a warning sign. That's because the declaration's [`isValid`](https://searchfox.org/mozilla-central/rev/6566d92dd46417a2f57e75c515135ebe84c9cef5/devtools/server/actors/styles.js#1447) flag is set on the actor but it no longer syncs with the client which uses the corresponding front to render the declaration after the change. Not returning the `StyleRuleActor` over the protocol breaks this sync actor-front sync. Differential Revision: https://phabricator.services.mozilla.com/D52560 --HG-- extra : moz-landing-system : lando |
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| .. | ||
| class-list.js | ||
| element-style.js | ||
| moz.build | ||
| rule.js | ||
| text-property.js | ||
| user-properties.js | ||