angular-cn/tools/public_api_guard/core
Miško Hevery 2961bf06c6 refactor(ivy): move `hostVars`/`hostAttrs` from instruction to `DirectiveDef` (#34683)
This change moves information from instructions to declarative position:
- `ɵɵallocHostVars(vars)` => `DirectiveDef.hostVars`
- `ɵɵelementHostAttrs(attrs)` => `DirectiveDef.hostAttrs`

When merging directives it is necessary to know about `hostVars` and `hostAttrs`. Before this change the information was stored in the `hostBindings` function. This was problematic, because in order to get to the information the `hostBindings` would have to be executed. In order for `hostBindings` to be executed the directives would have to be instantiated. This means that the directive instantiation would happen before we had knowledge about the `hostAttrs` and as a result the directive could observe in the constructor that not all of the `hostAttrs` have been applied. This further complicates the runtime as we have to apply `hostAttrs` in parts over many invocations.

`ɵɵallocHostVars` was unnecessarily complicated because it would have to update the `LView` (and Blueprint) while existing directives are already executing. By moving it out of `hostBindings` function we can access it statically and we can create correct `LView` (and Blueprint) in a single pass.

This change only changes how the instructions are generated, but does not change the runtime much. (We cheat by emulating the old behavior by calling `ɵɵallocHostVars` and `ɵɵelementHostAttrs`) Subsequent change will refactor the runtime to take advantage of the static information.

PR Close #34683
2020-01-24 12:22:10 -08:00
..
core.d.ts refactor(ivy): move `hostVars`/`hostAttrs` from instruction to `DirectiveDef` (#34683) 2020-01-24 12:22:10 -08:00
testing.d.ts feat(core): Deprecate TestBed.get as deprecated (#32406) 2019-09-11 20:28:56 -04:00