Producers represent values which can deliver change notifications.
When a producer value is changed, a change notification is propagated through the graph,
notifying live consumers which depend on the producer of the potential update.
Note here that this is a _potential_ update.
A producer may not have actually "changed" based on its equality function. With
this commit, before refreshing a view that is only marked for refresh
because its consumer is dirty, we poll producers for change to see if
they really have. If not, we can skip the refresh. The example test in this commit
shows that a `computed` which depends on a `signal` that is updated but
produces a value that is the same as before will _not_ cause the
component's template to refresh.
fixes#51797
PR Close#52476
This commit updates the reactive consumer used for `LView`s to be shared
between a component and its embedded views. This allows us to use the
consumer flag directly for a dirty indicator rather than needing to
find a component view for updating its flags.
In the future, this will also allow us to effectively poll producers to see if
they really changed before refreshing a view.
PR Close#52476
The significance of the combination of #51854 and #52302 went mostly
unnoticed. The first removed a unidirectional data flow constraint for
transplanted views and the second updated the signal implementation to
share transplanted view logic. The result is that we automatically get behavior
that (mostly) removes `ExpressionChangedAfterItWasCheckedError` when signals are
used to drive application state to DOM synchronization.
fixes#50320
PR Close#52476
This change updates the new build system migration guide with additional
information regarding the steps needed to convert an existing SSR project
to use the new integrated SSR capabilities.
PR Close#52485
This commit wraps the `load` event listener with `runOutsideAngular` to avoid
running unnecessary change detections on asynchronous tasks spawned within the
scope of the `ImagePerformanceWarning` functionality. This was previously causing
extra change detection cycles in development mode and interfering with debugging.
PR Close#52482
TypeScript JsDoc parsing, by default, treats occurences of Angular decorators (e.g. `@Component`) in JsDoc comments as JsDoc tags. This commit escapes these decorator strings by copying the raw JS doc onto a dummy symbol in a new SourceFile to make TypeScript re-parse the comment.
PR Close#52481
Adds build rules for "artificially" generating `DocEntry` collections for block and element APIs. The two rules are very similar, but _just_ different enough that it's worth having two separate implementations.
PR Close#52480
This adds a target to generate a manifest of all public api symbols. The majority of inputs are generated from the extraction rules, but API entries that don't have a TypeScript source symbol (elements and blocks) are defined in hand-written json collections.
PR Close#52472
This change skips signal equality calls on set / update when the
two values (current and the new one) are referentially identical.
The assumption is that equality function implementation should
never return false for 2 values that are the same (according to
the Object.is logic).
PR Close#52465
Eliminate all the remaining `cpl` names, and use `job` instead, which is the predominant convention.
Also, replace `.views.values()` with `.unit` in a few places, and perform the corresponding rename.
PR Close#52464
In this cleanup commit:
1. Add explanatory comments to all phases that were previously missing them.
2. Rename all phases, to eliminate the "phase" prefix, and directly describe their functions.
PR Close#52464
This commit removes the `finish` listener from the Animation object once
the animation is finished, effectively resolving a memory leak. Previously,
the `finish` listener captured `this`, which prevented `this` from being garbage collected.
PR Close#51136
`application` builder is preferred over `browser` builder. This updates all the examples I could find to use `application` builder. A couple notes of fixes that needed to happen:
1. The testing example was broken because it relied on `~` imports in CSS files, which is a Webpack-specific features. However I don't think we need those custom styles at all, so I just removed the import altogether.
2. A few tests seemed to be affected and needed to be cleaned up.
PR Close#52361
When an effect is created in a component constructor, it might read signals
which are derived from component inputs. These signals may be unreliable or
(in the case of the proposed input signals) may throw if accessed before the
component is first change detected (which is what makes required inputs
available).
Depending on the scenario involved, the effect may or may not run before
this initialization takes place, which isn't a great developer experience.
In particular, effects created during CD (e.g. via control flow) work fine,
as do effects created in bootstrap thanks to the sync CD it performs. When
an effect is created through dynamic component creation outside of CD though
(such as on router navigations), it runs before the component is first CD'd,
causing the issue.
In fact, in the signal components RFC we described how effects would wait
until ngOnInit for their first execution for exactly this reason, but this
behavior was never implemented as it was thought our effect scheduling
design made it unnecessary. This is true of the regular execution of effects
but the above scenario shows that *creation* of the effect is still
vulnerable. Thus, this logic is needed.
This commit makes effects sensitive to their creation context, by injecting
`ChangeDetectorRef` optionally. An effect created with an injector that's
tied to a component will wait until that component is initialized before
initially being scheduled. TestBed effect flushing is also adjusted to
account for the additional interaction with change detection.
PR Close#52473
By default, `toSignal` transforms an `Observable` into a `Signal`, including
the error channel of the Observable. When an error is received, the signal
begins throwing the error.
`toSignal` is intended to serve the same purpose as the `async` pipe, but
the async pipe has a different behavior with errors: it rejects them
outright, throwing them back into RxJS. Rx then propagates the error into
the browser's uncaught error handling logic. In the case of Angular, the
error is then caught by zone.js and reported via the application's
`ErrorHandler`.
This commit introduces a new option for `toSignal` called `rejectErrors`.
With that flag set, `toSignal` copies the async pipe's behavior, allowing
for easier migrations.
Fixes#51949
PR Close#52474
These special providers are configured when `walkProviderTree` is called. Because of this, they do not maintain any equality between subsequent runs of `walkProviderTree`. This prevents us from being able to compare the provider objects for equality between runs.
This commit changes the behaviour of getInjectorProviders to ignore these providers. In the future we will consider another approach for differentiating these providers from ones provided by users rather than the framework.
PR Close#52458
Recreates the fix for content projection in control flow in the new template pipeline. I also had to make the following adjustments to the pipeline:
1. The `TemplateOp.tag` property was being used to generate the name of the template function, rather than the actual tag name being passed into `ɵɵtemplate`. Since the content projection fix requires the tag name to be passed in, I've introduced a new `functionNameSuffix` property instead.
2. `TemplateOp.block` was being used to determine whether to pass `TemplateOp.tag` into the `ɵɵtemplate` instruction. Now that we're always passing in the tag name after the refactor in point 1, we no longer need this flag.
In addition to the refactors above, I also made some minor cleanups where I saw the opportunity to do so.
PR Close#52414
With the directive-based control flow users were able to conditionally project content using the `*` syntax. E.g. `<div *ngIf="expr" projectMe></div>` will be projected into `<ng-content select="[projectMe]"/>`, because the attributes and tag name from the `div` are copied to the template via the template creation instruction. With `@if` and `@for` that is not the case, because the conditional is placed *around* elements, rather than *on* them. The result is that content projection won't work in the same way if a user converts from `*ngIf` to `@if`.
These changes aim to cover the most common case by doing the same copying when a control flow node has *one and only one* root element or template node.
This approach comes with some caveats:
1. As soon as any other node is added to the root, the copying behavior won't work anymore. A diagnostic will be added to flag cases like this and to explain how to work around it.
2. If `preserveWhitespaces` is enabled, it's very likely that indentation will break this workaround, because it'll include an additional text node as the first child. We can work around it here, but in a discussion it was decided not to, because the user explicitly opted into preserving the whitespace and we would have to drop it from the generated code. The diagnostic mentioned point #1 will flag such cases to users.
Fixes#52277.
PR Close#52414
Previously, we would modified `dep.flags` directly to convert injection flags to booleans. This caused a mutation bug where subsequent calls to `getDependenciesFromInjectable` would result in the flags object containing false for every injection flag.
Now, we stop modifying `dep.flags` directly and instead assign the converted flags to a new object.
PR Close#52450
The current regexp supposes that there is at least one space between the `=` and the aliased variable.
As it is possible to write `let myIndex=index`, this commit updates the regexp to handle such a case.
PR Close#52444
Prior to this change, the transform function would be referenced with a potentially
relative import into an external declaration file. Such imports are not portable
and should not be created in this context. This commit addresses the issue by threading
though the originally used module specifier by means of the `Reference` type.
Fixes#52324
PR Close#52437
This commit fixes an issue where using literal types in the arguments of an input coercion
function could result in emitting invalid output, due to an assumption that TypeScript makes
when emitting literal types. Specifically, it takes the literal's text from its containing
source file, but this breaks when the literal type node has been transplanted into a
different source file. This issue has surfaced in the type-check code generator and is
already being addressed there, so this commit moves the relevant `TypeEmitter` class
from the `typecheck` module to the `translator` module, such that it can be reused for
emitting types in the type translator.
Fixes#51672
PR Close#52437
Fixes that our regex for parsing time values in defer blocks didn't allow for decimals. This isn't relevant for times in milliseconds, but it can be convenient to write something like `on timer(1.5s)`.
PR Close#52433
The `checkNoChanges` method does not belong in the API of production interface. `checkNoChanges` is
limited to testing and should not be used in any application code. Test
code should use `ComponentFixture` instead of `ChangeDetectorRef`.
Additionally, it is not desirable to have the `checkNoChanges` API
available in a context where `detectChanges` is not run first.
DEPRECATED: `ChangeDetectorRef.checkNoChanges` is deprecated.
Test code should use `ComponentFixture` instead of `ChangeDetectorRef`.
Application code should not call `ChangeDetectorRef.checkNoChanges` directly.
PR Close#52431
Adds some logic to skip over comments when resolving implicit `@defer` block triggers. This currently isn't a problem since we don't capture comments by default, but it may come up if we start capturing comments.
PR Close#52449
`RootViewRef<T>` extends `ViewRef<T>` and overrides 3 methods with behavior
that is identical to `ViewRef<T>`. This commit removes `RootViewRef<T>`
because it is not needed.
PR Close#52430
The `ViewRef<T>` interface extends `InternalViewRef` and is already not
part of the public API. There is no need for the extra `InternalViewRef`
interface. This confusing setup is likely leftover from the types
necessary to support both Ivy and ViewEngine.
PR Close#52430
When using `withFetch`, the `PRIMARY_HTTP_BACKEND` token is set.
The InMemory Backend services will also set that token.
This means that providers order will matter and the latest on the list will be the one instantiated
PR Close#52425
This commit adds a global epoch to the reactive graph, which can optimize
non-live reads.
When a non-live read occurs, a computed must poll its dependencies to check
if they've changed, and this operation is transitive and not cacheable.
Since non-live computeds don't receive dirty notifications, they're forced
to assume potential dirtiness on each and every read.
Using a global epoch, we can add an important optimization: if *no* signals
have been set globally since the last time it polled its dependencies, then
we *can* assume a clean state. This significantly improves performance of
large unwatched graphs when repeatedly reading values.
PR Close#52420
Alex Rickabaugh