Reworks the TCB for two-way bindings to make them simpler and to avoid regressions for two-way bindings to generic inputs. The new TCB looks as follows:
```
var _t1: Dir;
var _t2 = _t1.input;
(_t1 as typeof _t2 | WritableSignal<typeof _t2>) = expression;
```
PR Close#54252
Adds support for model inputs in the framework. `model()` returns a writable signal that implicitly defines a input/output pair that can be used either in two-way bindings to keep two values in sync or by binding individually to the input and output. When the value of the `model` changes, it will emit an event with the current value.
Furthermore, these changes expand two-way bindings to accept `WritableSignal`. This will make it easier to transition existing code to signals in a backwards-compatible way.
Example:
```ts
@Directive({
selector: 'counter',
standalone: true,
host: {
'(click)': 'increment()',
}
})
export class Counter {
value = model(0);
increment(): void {
this.value.update(current => current + 1);
}
}
@Component({
template: `<counter [(value)]="count"/> The current count is: {{count()}}`,
})
class App {
count = signal(0);
}
```
PR Close#54252
This commit adds a JIT transform for signal-based queries, so that
queries are working as expected in JIT environments like `ng test` where
decorator metadata is needed as a prerequisite for the component
definition creation.
This is similar to the JIT transforms for signal inputs etc.
PR Close#54257
The compileNgModuleFactory dont need to be in the application_ref file (in fact
the whole logic has little to do with ApplicationRef and it is not even called
from the application_ref). Performing this move to avoid circular dependencies
when the new query as signals authoring functions are exported.
PR Close#54103
This commit changes the approach to the reactive node representing query
results: instead of creating a custom node type we can use a computed -
the main change to get there is representing dirty change notification as
a signal (a counter updated every time a query changes its dirty status).
This change is dictated by simplification (we can avoid creation of a custom
signal type) as well as fixes to the multiple issues not covered by the
initial implementation:
- assuring referential stability of results (ex.: the same array instance
returned from child queries until results change);
- per-view results collection to avoid a situation where accessing query
results during view creation would return partial / inconsistent results;
- proper refresh of query results for both live and non-connected consumers.
All the above cases are covered by the additional tests in this commit.
PR Close#54103
This commit adds tests for content queries and fixes the arguments
order in the contentQuerySignal instruction, thus fixing a bug
discovered while adding tests.
PR Close#54103
This commits converts the hand-written tests into their usual,
compiled form. We can perform this change now since the compiler
bits of the queries-as-signal story landed.
PR Close#54103
Updates the acceptance authoring test compiler targets to support
multiple spec files. This will be useful for output, model, inputs
and queries.
PR Close#54253
This commit introduces the `output()` function and corresponding
runtime code.
In practice, `output()` will defer to `EventEmitter` as outlined in the
RFC, but we are considering limiting the type to a minimal version that
is not coupled with RxJS, less complex, and also has better type safety
around emitting of values.
E.g. currently `EventEmitter.emit` can always be called without
any value, even though the output may be typed to always pass around
values of type `T`. This could cause subtle and confusing bugs.
PR Close#54217
This test ensures that the `ExpressionChanged...` error does not happen
when signals are updated in a view that is attached to `ApplicationRef`
but was already checked. This was fixed in 432afd1ef4
which actually consequently fixes it for regular `markForCheck` as well.
PR Close#54206
* Renames the `input_signals` directory to `signals` so it can be reused for other tests.
* Reworks the build file to allow multiple test files.
PR Close#54213
Instead of maintaining individual transforms for `input`, `output`,
`model` etc. we are grouping them directly and the first one matching,
will execute.
This reduces needed traversal through AST and also makes it a little
more clean to write new initializer API metadata transforms.
Note: The Angular JIT transform is now also moving from `tooling.ts`
directly into `/transformers` for more local placement of transformer
logic.
PR Close#54200
Updates the template definition builder to emit the new format for the listener side of two-way bindings.
```js
// Before
listener("ngModelChange", function($event) {
return ctx.name = $event;
});
// After
ɵɵtwoWayListener("ngModelChange", function($event) {
ɵɵtwoWayBindingSet(ctx.name, $event) || (ctx.name = $event);
return $event;
});
```
PR Close#54154
It was always the intent to have `afterRender` hooks allow updating
state, as long as those state updates specifically mark views for
(re)check. This commit delivers that behavior. Developers can now use
`afterRender` hooks to perform further updates within the same change
detection cycle rather than needing to defer this work to another round
(i.e. `queueMicrotask(() => <<updateState>>)`). This is an important
change to support migrating from the `queueMicrotask`-style deferred
updates, which are not entirely compatible with zoneless or event `NgZone` run
coalescing.
When using a microtask to update state after a render, it
doesn't work with coalescing because the render may not have happened
yet (coalescing and zoneless use `requestAnimationFrame` while the
default for `NgZone` is effectively a microtask-based change detection
scheduler). Second, when using a `microtask` _during_ change detection to defer
updates to the next cycle, this can cause updates to be split across
multiple frames with run coalescing and with zoneless (again, because of
`requestAnimationFrame`/`macrotask` change detection scheduling).
PR Close#54074
When the zoneless scheduler is provided, we want to update the behavior
of `ComponentFixture` to address common issues and painpoints in testing.
Developers should never have to call `detectChanges` on a fixture
manually. Instead of calling `detectChanges` after performing an
action that updates state and requies a template refresh, developers
should wait for change detection to run because the update needs to also have
notified the scheduler. If this was not the case, the component would
not work correctly in the application. Calling `detectChanges` to force
an update could hide real bugs.
This commit also updates the zoneless tests to uses `ComponentFixture`
instead of manually attaching to the `ApplicationRef` and rewriting a
lot of the helpers (`getDebugNode`, `isStable` as a value, `whenStable` as a
Promise).
PR Close#54024
This commit separates `InputSignal` for input signals with transforms.
The reason being that most of the time, signal inputs are not using
transforms and the generics are rather confusing.
Especially for users with inferred types displayed in their IDEs, the
input signal types are seemingly complex, even if no transform is used.
For this reason, we are introducing a new type called
`InputSignalWithTransform`. This type will be used for inputs with
transforms, while non-transform inputs just use `InputSignal`.
A notable fact is that `InputSignal` extends `InputSignalWithTransform`,
with the "identity transform". i.e. there is no transform. This allows
us to share the code for input signals. In practice, we don't expect
users to pass around `InputSignal`'s anyway.
PR Close#54053
Follow-up to #54002 that:
* Remove the `toString` implementation from the `primitives`.
* Guards the `toString` with `ngDevMode` and prints out the value.
PR Close#54079
Since signals are function, currently stringifying them reveals the implementation of the function. This can lead to confusion since it contains internal implementation details. These changes add static `toString` function to address the issue.
**Note:** it's tempting to have `toString` output the actual value of the signal, but that would encourage users not to call the function which will be problematic in the long run. That's why these changes are using a static string instead.
PR Close#54002
This is a refactor commit that moves more query construction / refresh
logic from the body of instructions into dedicated functions. This is
in preparation for the signal-based query instructions.
PR Close#54017
Similar to signal-based inputs, we support signal-based queries in JIT
by expecting a decorator to be added. This is a consequence of the
design, given that JIT requires query declaration information before
the class is initialized- but ironically there is no way to collect this
information without instantiating the class.
A JIT transform in the Angular CLI will automatically generate these
decorators for testing.
PR Close#54019
While `Array.at` is technically supported in all browsers we officially
support, the change was needlessly breaking without any real benefit.
PR Close#54021
Node removal is immediate and does not require change detection to run
when animations are not provided. This refactor makes the animation
engine notify the scheduler rather than doing it on all node removals.
PR Close#53857
The new type testing infrastructure was introduced for the input-as-signals
authoring functions. This commit modifies this infrastructure to make it more
generic and support queries-as-signals.
PR Close#53829
This commit splits the query implementation and instructions
into a separate files. This is a pattern frequently used by
other functional areas of the framework and is a preparation for
introducing queries-as-signals where we are going to see more
instructions delegating to the same core functionality.
PR Close#53922
Prior to this commit, `TestBed` would require tests call `flushEffects`
or `fixture.detectChanges` in order to execute effects. In general, we
want to discourage authoring tests like this because it makes the timing
of change detection and effects differ from what happens in the
application. Instead, developers should perform actions and `await` (or
`flush`/`tick` when using `fakeAsync`) some `Promise` so that Angular
can react to the changes in the same way that it does in the
application.
Note that this still _allows_ developers to flush effects synchronously
with `flushEffects` and `detectChanges` but also enables the <action>,
`await` pattern described above.
PR Close#53843
Enables signal inputs for existing Zone based components.
This is a next step we are taking to bring signal inputs earlier to the Angular community.
The goal is to enable early access for the ecosystem to signal inputs, while we are continuing
development of full signal components as outlined in the RFC. This will allow the ecosystem
to start integrating signals more deeply, prepare for future migrations, and improves code quality
and DX for existing components (especially for OnPush).
Based on our work on full signal components, we've gathered more information and learned
new things. We've improved the API by introducing a way to intuitively declare required inputs,
as well as improved the API around initial values. We even support non-primitive initial values
as the first argument to the `input` function now.
```ts
@Directive({..})
export class MyDir {
firstName = input<string>(); // string|undefined
lastName = input.required<string>(); // string
age = input(0); // number
```
PR Close#53872
This allows us to ensure signal inputs and a potential JIT transform
remain single file compilation compatible. The consequences are that
options need to be statically analyzable more strictly, compared to
loosened restrictions with static interpretation where e.g. `alias`
can be defined through a shared variable.
PR Close#53872
Adds infrastructure to run signal input tests with JIT (using the
transform) and AOT. Acceptance tests for signal inputs will run with
both variants. In the future we can consider expanding this
infrastructure for all of our acceptance tests, but that's a different
story.
PR Close#53808
This commit creates a small http server Angular application playground
for playing with signal inputs. This is useful for development and also
validates some of the common input patterns.
PR Close#53808
Kristiyan Kostadinov