Exposes the function used to transform an input on `ComponentFactory.inputs` and `ComponentMirror.inputs`. We'll need this to support input transforms in `elements`.
PR Close#50713
Extend toSignal to accept any Subscribable (instead of only Observable)
for consistency with AsyncPipe and for broader compatibility with any
observable library (that is compatible with the Subscribable interface).
This is only a type change as the implementation does not use anything
else than the Subscribable interface anyway.
PR Close#50162
According to the HTML specification most attributes are defined as strings, however some can be interpreted as different types like booleans or numbers. [In the HTML standard](https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#boolean-attributes), boolean attributes are considered `true` if they are present on a DOM node and `false` if they are omitted. Common examples of boolean attributes are `disabled` on interactive elements like `<button>` or `checked` on `<input type="checkbox">`. Another example of an attribute that is defined as a string, but interpreted as a different type is the `value` attribute of `<input type="number">` which logs a warning and ignores the value if it can't be parsed as a number.
Historically, authoring Angular inputs that match the native behavior in a type-safe way has been difficult for developers, because Angular interprets all static attributes as strings. While some recent TypeScript versions made this easier by allowing setters and getters to have different types, supporting this pattern still requires a lot of boilerplate and additional properties to be declared. For example, currently developers have to write something like this to have a `disabled` input that behaves like the native one:
```typescript
import {Directive, Input} from '@angular/core';
@Directive({selector: 'mat-checkbox'})
export class MatCheckbox {
@Input()
get disabled() {
return this._disabled;
}
set disabled(value: any) {
this._disabled = typeof value === 'boolean' ? value : (value != null && value !== 'false');
}
private _disabled = false;
}
```
This feature aims to address the issue by introducing a `transform` property on inputs. If an input has a `transform` function, any values set through the template will be passed through the function before being assigned to the directive instance. The example from above can be rewritten to the following:
```typescript
import {Directive, Input, booleanAttribute} from '@angular/core';
@Directive({selector: 'mat-checkbox'})
export class MatCheckbox {
@Input({transform: booleanAttribute}) disabled: boolean = false;
}
```
These changes also add the `booleanAttribute` and `numberAttribute` utilities to `@angular/core` since they're common enough to be useful for most projects.
Fixes#8968.
Fixes#14761.
PR Close#50420
Hydration requires a stable App to run some logic.
With this warning developers will be informed about potential issues encountered when running an unstable app.
Fixes#50285
PR Close#50295
Unlike the current signature where the input argument must a function, this change allows an input of any type to be passed to the `isSignal` function.
PR Close#50035
This commit introduces an interface for `toSignal` options to mirror that of
`toObservable`, and adjusts docs for both symbols. It also adds the ability
for `toSignal` to manually specify `DestroyRef` (similarly to
`toObservable` accepting an injector) or for `toSignal` automatic cleanup to
be disabled (in which case the subscription persists until the Observable
completes). Either option allows `toSignal` to be used outside of a DI
context, like `toObservable`.
PR Close#50071
It might happen that the lifecycle scope represented by DestroyRef becomes
invalid before an onDestroy hook is registered (ex. injector or component
instance got destroyed). In such cases registration of the onDestroy hooks
should no longer be possible.
Fixes#49658
PR Close#49804
The new asReadonly method on the WritableSignal interface makes
it possible to create readonly instance of a writable signal.
Readonly signals can be accessed to read their value,
but can't be changed using set, update or mutate methods.
PR Close#49802
The initial value used for signals by default is now `undefined`. In
addition, there is a new option to express that the signal should emit a
value synchronously (`requireSync: true`). When this value is specified,
the function will throw _on creation_ if the subscribing to the
`Observable` does not result in a synchronous emit.
PR Close#49769
This change makes is possible to use async functions
(ones returning a promise) as effect run functions.
To make it possible, the signature of the effect function
changed: effect cleanup function is registered now
(using a dedicated callback passed to the effect creation)
instead of being returned from the effect function.
PR Close#49783
This commit updates the logic to detect a situation when hydration support was enabled only on the client. If that happens, Angular produces a warning in a console with a link to the error guide.
PR Close#49743
Currently, non-destructive hydration for i18n blocks is not supported (but support is coming!).
This commit updates the serialization logic from throwing an error when it comes across an i18n
block to annotating a component with a skip hydration flag.
PR Close#49722
Previously, attempting to turn off the `experimentalDecorators` TypeScript configuration
option within an Angular project would result in build time errors. These errors were due
to an exposed Decorator signature from `@angular/core` that TypeScript thought was incompatible
with standard decorators. However, Angular's class decorators (`Component`, `Directive`, `Pipe`,
`Injectable`, `NgModule`) are actually already compatible with standard decorators. The export types for
the decorators only needed to be updated to reflect that compatibility. With the updated exported types,
applications will now successfully compile and execute in AOT mode with one important dependency injection
caveat explained in the note below.
For JIT mode applications that are built with the Angular CLI, `@ngtools/webpack`, or use `tsickle`,
there were also no additional changes required. These tools automatically convert property decorators
(now called field decorators) at build time to store Angular property metadata directly on the relevant
class. Building with these tools is the overwhelmingly common method of building an application. Any
applications that do not use one of these tools will not function at runtime in JIT mode if using standard
decorators. The behavior and code for when experimental decorators is enabled has been left intact.
NOTE: Angular constructor dependency injection that requires parameter decorators is not supported.
The standard decorator specification does not support parameter decorators. The `inject` function must be
used for all cases that previously required a parameter decorator. This includes such decorators as `Inject`,
`Optional`, `Self`, `SkipSelf`, `Host`, and `Attribute`. Constructor dependency injection that relies only
on the supplied parameter type will continue to function as expected if using AOT; as well as in JIT mode
if using the Angular CLI, `@ngtools/webpack` directly, or `tsickle`.
Documentation for the `inject` function can be found at: https://angular.io/api/core/inject
The decorator specification proposal can be found at: https://github.com/tc39/proposal-decorators
PR Close#49492
The `ReflectiveInjector` symbol has been deprecated in v5 (11 major versions ago). This commit removes ReflectiveInjector and related symbols.
BREAKING CHANGE: The `ReflectiveInjector` and related symbols were removed. Please update the code to avoid references to the `ReflectiveInjector` symbol. Use `Injector.create` as a replacement to create an injector instead.
PR Close#48103
To match the behaviour of Array.filter, typeguards can now be used on QueryList.filter to narrow the return type.
Fixes#38446
BREAKING CHANGE: QueryList.filter now supports type guard functions, which will result in type narrowing. Previously if you used type guard functions, it resulted in no changes to the return type. Now the type would be narrowed, which might require updates to the application code that relied on the old behavior.
PR Close#48042
This change exposes the onDestroy callback on the ApplicationRef
as the public API. It is useful for cases where people need to
execute cleanup logic on application teardown.
Closes#49087
PR Close#49677
This commit adds a provider function that allows developers to configure
the `NgZone` instance for the application. In the future, this provider
will be used for applications to specifically opt-in to change detection
powered by ZoneJS rather than it being provided by default.
This API does _not_ specifically provide support for developers to define their own
`NgZone` implementation or opt in to `NoopNgZone` directly. Both of
these are possible today, but are effectively unsupported (applications
that use these are left to their own devices to run change detection at
the appropriate times). That said, developers can still use DI in
`bootstrapApplication` to provide an `NgZone` implementation instead,
it's just not specifically available in the
`provideZoneChangeDetection` function.
PR Close#49557
* Prevent reads of signals during the notification process. This shouldn't
ever be triggered by user code but is more of a preventative for
internal misuse. Reading a signal during notification would/could create
glitches where the values being read are not updated to reflect the
values being updated by the notification.
* Prevent signal writes inside of computed's. These are meant to be
derived values and should not have any side-effects like writing new
values to other signals
* Prevent signal writes inside of effects by default. Writing to signal
values during the execution of an effect can lead to the
`ExpressionChangedAfterItHasBeenCheckedError` if writing to signals
that represent global state which is read in a parent component. This is
mostly just a problem for `OnPush`/`CheckAlways` components, but with
signals being new and pure signal components not even available yet,
it will be the majority for a long time.
PR Close#49631
This commit implements an RxJS operator `takeUntilDestroyed` which
terminates an Observable when the current context (component, directive,
etc) is destroyed. `takeUntilDestroyed` will inject the current `DestroyRef`
if none is provided, or use one provided as an argument.
PR Close#49154
This commit adds the basic sketch for the implementation of `fromObservable`
and `fromSignal`, the two basic primitives which form the RxJS interop layer
with signals.
PR Close#49154
This commit adds the infrastructure for `@angular/core/rxjs-interop`, a new
core entrypoint which provides bidirectional interoperability between
Angular's built-in reactivity system of synchronous signals, and the RxJS
`Observable` abstraction.
The new entrypoint is set up as an empty shell in this commit, with its
implementation to follow in a followup.
PR Close#49154
We've been experimenting with the DeepReadonly type that would make
signal values deeply read-only and prevent accidental changes without
going to the owner of data. What we've found out during the experiments
is that additional safety net has more drawbacks than benefits: it just
introduces too much friction to be practical for daily usage.
PR Close#49154
This change extends the effect API surface so effects can, optionally,
return a cleanup function. Such function, if returned, is executed
prior to the subsequent effect run.
PR Close#49625
This commits adds `makeStateKey`, `StateKey` and `TransferState` methods in `@angular/core` as public API and deprecated the same exported symbols in `@angular/platform-browser`.
DEPRECATED: `makeStateKey`, `StateKey` and `TransferState` exports have been moved from `@angular/platform-browser` to `@angular/core`. Please update the imports.
```diff
- import {makeStateKey, StateKey, TransferState} from '@angular/platform-browser';
+ import {makeStateKey, StateKey, TransferState} from '@angular/core';
```
PR Close#49563
Signal functions are marked with a `[SIGNAL]` symbol property, which was
previously set to `true`.
This commit changes the `[SIGNAL]` property to have the `ReactiveNode` as
its value instead. This doesn't change the behavior of the signal library
itself, but exposes the signal internals in a way where developer tooling
can look at any signal and interact with its dependency graph.
PR Close#49529
This commit adds a `DeepReadonly` type to the signals API, and makes signal
getters return an immutable version of their value type. This doesn't
prevent all mutation but adds some friction against modifying the values
within signals outside of the proper mutation APIs.
PR Close#49529
The `effect` implemented in the signal library is useful for testing but
does not integrate with Angular. This commit moves that code to the
actual framework package and integrates it with automatic cleanup via
`DestroyRef`. A simpler effect implementation is used in the signal tests to
test the `Watch` primitive.
Further commits will update the scheduling to tie effects together with
change detection.
PR Close#49529
Paul Gschwendtner