This commit adds an ngTemplateGuard_ngIf static method to the NgIf
directive and an ngTemplateContextGuard static method to NgFor. The
function of these two static methods is to enable type narrowing
within generated type checking code for consumers of the directives.
PR Close#26203
`NgForOf` used to implement `OnChanges` and than use
`ngOnChanges` callback to detect when `ngForOf` binding
changed to update the differ. We now do the checking
manually which puts less pressure on the runtime to do
the bookkeeping and should result in minor perf improvement.
PR Close#23378
The utility functions `formatNumber`, `formatPercent`, `formatCurrency`, and `formatDate` used by the number, percent, currency and date pipes are now available for developers who want to use them outside of templates.
Fixes#20536
PR Close#22423
The AsyncPipe type signature was changed to allow
deferred creation of promises and observalbes that
is supported by the implementation by allowing
`Promise<T>|null|undefined` and by allowing
`Observable<T>|null|undefined`.
PR Close#22169
Currently, NavigationStart there is no way to know if an navigation was triggered imperatively or via the location change. These two use cases should be handled differently for a variety of use cases (e.g., scroll position restoration). This PR adds a navigation source field and restored navigation id (passed to navigations triggered by a URL change).
PR Close#21728
Currently, NavigationStart there is no way to know if an navigation was triggered imperatively or via the location change. These two use cases should be handled differently for a variety of use cases (e.g., scroll position restoration). This PR adds a navigation source field and restored navigation id (passed to navigations triggered by a URL change).
PR Close#21728
Allows a directive to use the expression passed directly to a property
as a guard instead of filtering the type through a type expression.
This more accurately matches the intent of the ngIf usage of its template
enabling better type inference.
Moved NgIf to using this type of guard instead of a function guard.
Closes: #20967
Structural directives can now specify a type guard that describes
what types can be inferred for an input expression inside the
directive's template.
NgIf was modified to declare an input guard on ngIf.
After this change, `fullTemplateTypeCheck` will infer that
usage of `ngIf` expression inside it's template is truthy.
For example, if a component has a property `person?: Person`
and a template of `<div *ngIf="person"> {{person.name}} </div>`
the compiler will no longer report that `person` might be null or
undefined.
The template compiler will generate code similar to,
```
if (NgIf.ngIfTypeGuard(instance.person)) {
instance.person.name
}
```
to validate the template's use of the interpolation expression.
Calling the type guard in this fashion allows TypeScript to infer
that `person` is non-null.
Fixes: #19756?
PR Close#20702
Alex Rickabaugh
Igor Minar
Alex Eagle
Pete Bacon Darwin
Fabian Wiles
Victor Savkin
Miško Hevery
Matias Niemelä
George Kalpakas
Alan
Olivier Combe
Victor Berchet
Chuck Jazdzewski
vsavkin
Jason Aden
tinayuangao