Currently we read lifecycle hooks eagerly during `ɵɵdefineComponent`.
The result is that it is not possible to do any sort of meta-programing
such as mixins or adding lifecycle hooks using custom decorators since
any such code executes after `ɵɵdefineComponent` has extracted the
lifecycle hooks from the prototype. Additionally the behavior is
inconsistent between AOT and JIT mode. In JIT mode overriding lifecycle
hooks is possible because the whole `ɵɵdefineComponent` is placed in
getter which is executed lazily. This is because JIT mode must compile a
template which can be specified as `templateURL` and those we are
waiting for its resolution.
- `+` `ɵɵdefineComponent` becomes smaller as it no longer needs to copy
lifecycle hooks from prototype to `ComponentDef`
- `-` `ɵɵNgOnChangesFeature` feature is now always included with the
codebase as it is no longer tree shakable.
Previously we have read lifecycle hooks from prototype in the
`ɵɵdefineComponent` so that lifecycle hook access would be monomorphic.
This decision was made before we had `T*` data structures. By not
reading the lifecycle hooks we are moving the megamorhic read form
`ɵɵdefineComponent` to instructions. However, the reads happen on
`firstTemplatePass` only and are subsequently cached in the `T*` data
structures. The result is that the overall performance should be same
(or slightly better as the intermediate `ComponentDef` has been
removed.)
- [ ] Remove `ɵɵNgOnChangesFeature` from compiler. (It will no longer
be a feature.)
- [ ] Discuss the future of `Features` as they hinder meta-programing.
Fix#30497
PR Close#35464
Prior to this commit, calling change detection for destroyed views resulted in errors being thrown in some cases. This commit adds a check to make sure change detection is invoked for non-destroyed views only.
PR Close#34241
This commit fixes a compatibility bug where pre-order lifecycle
hooks (onInit, doCheck, OnChanges) for directives on the same
host node were executed based on the order the directives were
matched, rather than the order the directives were instantiated
(i.e. injection order).
This discrepancy can cause issues with forms, where it is common
to inject NgControl and try to extract its control property in
ngOnInit. As the NgControl directive is injected, it should be
instantiated before the control value accessor directive (and
thus its hooks should run first). This ensures that the NgControl
ngOnInit can set up the form control before the ngOnInit
for the control value accessor tries to access it.
Closes#32522
PR Close#34026
Ports render3 onDestroy tests over to be acceptance tests. Removes old render3 tests if possible.
Note the onlyInIvy test for one area where Ivy has a different behavior than ViewEngine
PR Close#30445
Misko Hevery
Joey Perrott
Andrew Kushnir
Kara Erickson
crisbeto
Ben Lesh
Marc Laval