Switches the syntax for blocks from `{#block}{/block}` to `@block {}` based on the feedback from the community.
Read more about the decision-making process in our blog: https://blog.angular.io/meet-angulars-new-control-flow-a02c6eee7843
The existing block types changed in the following ways:
**Conditional blocks:**
```html
<!-- Before -->
{#if cond}
Main content
{:else if otherCond}
Else if content
{:else}
Else content
{/if}
<!-- After -->
@if (cond) {
Main content
} @else if (otherCond) {
Else if content
} @else {
Else content
}
```
**Deferred blocks**
```html
<!-- Before -->
{#defer when isLoaded}
Main content
{:loading} Loading...
{:placeholder} <icon>pending</icon>
{:error} Failed to load
{/defer}
<!-- After -->
@defer (when isLoaded) {
Main content
} @loading {
Loading...
} @placeholder {
<icon>pending</icon>
} @error {
Failed to load
}
```
**Switch blocks:**
```html
<!-- Before -->
{#switch value}
{:case 1}
One
{:case 2}
Two
{:default}
Default
{/switch}
<!-- After -->
@switch (value) {
@case (1) {
One
}
@case (2) {
Two
}
@default {
Default
}
}
```
**For loops**
```html
<!-- Before -->
{#for item of items; track item}
{{item.name}}
{:empty} No items
{/for}
<!-- After -->
@for (item of items; track item) {
{{item.name}}
} @empty {
No items
}
```
PR Close#51891
This commit disables a couple newly-added tests related to `on idle` trigger condition for @defer blocks. Tests would be re-enabled back once we identify the reason of flakiness and fix it.
PR Close#51895
This commit adds a logic to handle `on immediate` conditions both as a main condition, as well as a prefetching condition (i.e. `prefetch on immediate`).
PR Close#51630
Adds support for `on viewport` and `prefetch on viewport` triggers which will load the deferred content when the element comes into the view.
PR Close#51874
Adds support for `on hover` and `prefetch on hover` triggers. Some code had to be moved around so it could be reused from the `on interaction` triggers.
PR Close#51874
The `NoopAnimationDriver` as static property of `AnimationDriver` prevents it from being removed by tree shaking. This commit deprecates it and exposes the `NoopAnimationDriver` on the public API to replace its usage.
DEPRECATED:
The `AnimationDriver.NOOP` symbol is deprecated, use `NoopAnimationDriver` instead.
PR Close#51843
This change simply flip the flag which enables using the deps tracker in JIT compilation (the logic is already implemented in a previous PR). Some tests which depend on the old JIT implementation (e.g., patching the scope info into the type) are modified accordingly.
PR Close#51415
This PR moves the Observable subscription of toSignal outside of the
reactive context. As the result the toSignal calls are allowed in the
computed, effect and all other reactive consumers.
This is based on the reasoning that we already allow signals creation
in a reactive context. Plus a similar change was done to the async pipe
in the https://github.com/angular/angular/pull/50522Fixes#51027
PR Close#51831
Standalone component need to include the imported NgModules as part of their dependencies in order to be able to use the injection tokens coming from these NgModules. To do so, in this change the imported NgModules are included in the standalone component compilation scope.
PR Close#51819
The browserUrlTree is only used to support the onSameUrlNavigation: 'ignore' logic. We can achieve this functionality without having this state tracked inside the Router. Instead, we can re-examine what ignore means: We don't want to rerun the matching logic, guards, or resolvers when we already know that nothing is changing.
Outside of the "navigated", there are two things that constitute a "change":
1. The browser URL might change. Because of skipLocationChange, the browser URL might not always match the internal state of the Router (we can navigate to a path but skip updating the browser URL). If we're navigating to a place that would change the browser URL, we should process the navigation. Theoretically, all we need to really do is update the browser URL instead of processing the whole navigation w/ guards, redirects, and resolvers. But this doesn't matter that much because the default value for runGuardsAndResolvers will skip all of this anyways.
2. The internal state of the Router might change. That is, we're navigating to a new path and may or may not be updating the updating the browser URL.
If either of the above are true, we process the navigation. If both are false, we aren't changing anything so we can safely ignore the navigation request (as long as onSameUrlNavigation === 'ignore').
Why is this change important?
* Simplification of Router internals. The Router has a lot of special case handling and one-offs to handle a limited set of scenarios. Removing these when possible makes the code easier to follow
PR Close#48065
The `malformedUriErrorHandler` is used as a recovery mechanism for when the `UrlSerializer`
throws an error when parsing a URL string. If custom error handling is
desired for this, it should instead be done inside the
`UrlSerializer.parse` method itself. There's no reason to have an entire
feature option built around what can otherwise just be `try...catch`.
BREAKING CHANGE: `malformedUriErrorHandler` is no longer available in
the `RouterModule.forRoot` options. URL parsing errors should instead be
handled in the `UrlSerializer.parse` method.
PR Close#51745
Currently deps tracker includes the exported scope of the exported NgModule only in the exported scope of that NgModule. This is in agreement with what AoT does today. But JIT diverges from this behavior by including these exported scopes into the compilation scope as well. Since deps tracker is going to be used for both AoT (local compilation mode) and JIT, the question might be which behavior the deps tracker should follow? Today it follows the AoT one, but it breaks some tests in Google which seem to depend on this behavior of JIT. So it is better to migrate deps tracker to what JIT does. This leads to a wider compilation scope in local compilation compared to full compilations, but it won't break any existing thing.
PR Close#51791
This change contains runtime logic needed to flatten the NgModule bootstrap field in local compilation mode. While it is quite odd to pass a "nested" array as NgModule bootstrap, it is still required to support this case in local compilation mode since it is supported in full compilation mode.
PR Close#51767
This change flattens the imports info on standalone component decorators in runtime dev mode by adding flattening logic to the deps tracker. Such flattening has no effect in AoT full compilation mode since these arrays are already resolved and flattened by AoT static analysis, but in local compilation mode it is needed since the raw array as appears on the component decorator will be passed to the deps tracker, and so it needs to be flattened.
This change does not affect prod runtime since deps tracker is only used in dev mode.
PR Close#51767
This change flattens the imports/exports/declarations info on ngModule decorators in runtime dev mode by adding flattening logic to the runtime `ɵɵsetNgModuleScope`. Such flattening has no effect in AoT full compilation mode since these arrays are already resolved and flattened by AoT static analysis, but in local compilation mode it is needed since the raw array as appears on the NgModule decorator will be passed to the runtime `ɵɵsetNgModuleScope`, and so it needs to be flattened.
This change has to effect on prod runtime as `ɵɵsetNgModuleScope` is not used in prod.
PR Close#51767
upgrade the warning for lazy-loaded lcp images when using NgOptimizedImage to an error
BREAKING CHANGE:
Previously when NgOptimizedImage directive detected that an LCP image is lazy-loaded, a console warning was produced. Now the directive throws an error to make it more discoverable in a console. If you receive this error, refer to this guide for additional information: https://angular.io/guide/image-directive#step-4-mark-images-as-priority
PR Close#51748
This commit moves the destroy logic from 'effect' in the lower-level
'watch' so this implementation is shared among varius watch implementations.
PR Close#51757
Certain code patterns and tools in Google (and possibly 3P world) lead to the situation that a component is bootstrapped/rendered without its ng-module being loaded in the browser. Technically speaking this should be an anti-pattern since the ng-module could contain some runtime logic (e.g., providing something, calling some services, etc) and its not being loaded leads to unexpected behaviour. However, in many cases ng-module is an empty class and its only usage is for providing scope, and since in AoT full compilation mode we already hard-code dependencies into components so we can get away with not loading the ng-module. But in AoT local compilation mode it is not possible to get away since the component's dependencies are computed in runtime and the presence of the corresponding ng-module in the browser is needed. For this reason in this change it is forbidden to attempt to render a component without first loading its ng-module in local compilation mode and an explicit error message is created to make this situation clear. This error message can help with catching such cases when running TGP in Google.
It would be an interesting question as to whether to ban this situation in full compilation mode as well, as it is error prone and these errors are sometimes very hard to debug.
PR Close#51726
When a producer is no longer used, the consumer has to update its internal data structure
that keeps track of all producers. There used to be an issue where only half of the stale
producers would actually be removed from this data structure, as the intended upper bound
of the number of producers to remove would decrease with each removed producer, therefore
not reaching all producers that should be removed from the data structure.
This commit fixes the issue by truncating the arrays directly, without going through
individual `pop` operations. An assertion that would catch the inconsistent state in
the internal data structures of the signal graph has been introduced.
PR Close#51722
Adds support for passing in `@Component.styles` as a string. Also introduces a new `styleUrl` property on `@Component` for providing a single stylesheet. This is more convenient for the most common case where a component only has one stylesheet associated with it.
PR Close#51715
Currently internally Angular has some customized tsconfig files, because we don't align with the tsconfig of the rest of g3. These changes enable `noImplicitReturns` and `noPropertyAccessFromIndexSignature` to align better with the internal config.
PR Close#51728
Previously effects were queued as they became dirty, and this queue was
flushed at various checkpoints during the change detection cycle. The result
was that change detection _was_ the effect runner, and without executing CD,
effects would not execute. This leads a particular tradeoff:
* effects are subject to unidirectional data flow (bad for dx)
* effects don't cause a new round of CD (good/bad depending on use case)
* effects can be used to implement control flow efficiently (desirable)
This commit changes the scheduling mechanism. Effects are now scheduled via
the microtask queue. This changes the tradeoffs:
* effects are no longer limited by unidirectional data flow (easy dx)
* effects registered in the Angular zone will trigger CD after they run
(same as `Promise.resolve` really)
* the public `effect()` type of effect probably isn't a good building block
for our built-in control flow, and we'll need a new internal abstraction.
As `effect()` is in developer preview, changing the execution timing is not
considered breaking even though it may impact current users.
PR Close#51049
The View Transitions API enables easy animations when transitioning between different DOM states. This commit adds an opt-in feature to the Router which runs the component activation and deactivation logic in the document.startViewTransition callback. If the browser does not support this API, route activation and deactivation will happen synchronously.
resolves#49401
PR Close#51314
Improves the error handling story for after*Render by delegating errors to an ErrorHandler, so that one failure does not break every callback.
PR Close#51662
For redirects, most of the logic between wildcard and regular redirects
is identical. Combine what can be combined there. Once that was done,
the first part of the matching for redirects looks almost identical to the regular
matching. Create helpers and combine simplify code where possible there
as well.
PR Close#51543
This commit updates the logic to add `prefetch on idle` support for defer blocks. Previously, the `on idle` logic was already implemented for the main loading and rendering. This commit reuses the same logic to bring it to the prefetching mechanism.
PR Close#51629
These changes build on top of #51514 to add support for advanced expressions inside the `track` parameter of `for` loop blocks. There are two different outputs that the compiler can generate:
1. If the tracking function only references the item or `$index`, the compiler generates a pure arrow function as a constant references in the `repeaterCreate` instruction.
2. If the tracking function has references to properties outside of the `for` loop block, the compiler will rewrite those references to go through `this` and generate a function declaration. The runtime will `bind` the declaration to the current component instance so that the rewritten `this` references are resolved correctly.
Advanced tracking expression come with the following limitations to ensure the best possible performance:
1. They can only reference the item, `$index` and properties directly on the component instance. This means that there'll be an error when accessing this like local template variables and references. While we could get this to work, we would have to traverse the context tree at runtime which will degrade the performance of the loop, because it's a linear time operation that is performed on each comparison. Furthermore, allowing local references would require us re-evaluate the list when any one of them has changed.
2. Pipes aren't allowed inside the tracking function.
3. Object literals and pipes used inside the tracking expression will be recreated on each invocation.
PR Close#51618
This commit updates the runtime implementation of defer blocks to avoid their triggering on the server. This behavior was described in the RFC (https://github.com/angular/angular/discussions/50716, see "Server Side Rendering Behavior" section): only a placeholder is rendered on the server at this moment. This commit also updates the logic to make sure that the placeholder content is hydrated after SSR.
PR Close#51530
This commit fixes a bug in the change detection algorithm that would
ignore the `OnPush`/dirty flag of a component's host when it is created
dynamically. That is, `OnPush` components that were not marked dirty but
were created as embedded views would have their host bindings and `ngDoCheck`
function always run even if they were not dirty.
BREAKING CHANGE: `OnPush` components that are created dynamically now
only have their host bindings refreshed and `ngDoCheck run` during change
detection if they are dirty.
Previously, a bug in the change detection would result in the `OnPush`
configuration of dynamically created components to be ignored when
executing host bindings and the `ngDoCheck` function. This is
rarely encountered but can happen if code has a handle on the
`ComponentRef` instance and updates values read in the `OnPush`
component template without then calling either `markForCheck` or
`detectChanges` on that component's `ChangeDetectorRef`.
PR Close#51356
This commit refactors the router internals to track state inside a separate
`StateManager`. This helps open the door to managing the state in
different, swappable providers. The current interface needed by the
Router is: `currentUrlTree`, `rawUrlTree`, `browserUrlTree`,
`routerState`, and `handleNavigationEvent` (other properties are because
some router properties are writeable when they shouldn't be). This is
a suprisingly small interface and can hopefully be made smaller in the
future (i.e. removing 1 or more of the 3 tracked of `UrlTree`s).
PR Close#48481
This commit switches the signals library from a bidirectional symmetric
dependency graph using weak references, to a bidirectional _asymmetric_
graph which uses strong references. This is made possible with a reference
counting algorithm which only tracks producer -> consumer references for
effect-like "live" consumers, preventing memory leaks.
The new algorithm should be simpler and faster than the previous
implementation as weak references are fairly slow to create and traverse.
A tradeoff is that non-live consumers must now poll their producers when
read, as they cannot rely on dirty notifications.
As part of this refactoring, the `ReactiveNode` class is replaced with an
interface instead, and methods are moved to standalone functions. This is
paired with instantiating individual signals/computeds via `Object.create`
against a prototype node which contains static or initial values. This
technique, in conjunction with the rest, greatly improves the performance
of node creation.
PR Close#51226
The data `Observable` is not updated unless there have been changes to
the object. The current diffing does not look at `symbol` keys of the
object but the `title` property is stored as a private `symbol`. This
commit updates the object diffing to include symbols.
fixes#51401
PR Close#51561
With the new control flow and defer blocks it'll be common for several template instructions to be declare one after another. These changes add support for chaining to the `template` instruction which will allow us to save some bytes.
PR Close#51546
This commit fixes an issue where serialization of a view container fails in case it uses a component host as an anchor. This fix is similar to the fix from #51247, but for cases when we insert a component (that acts as a host for a view container) deeper in a hierarchy.
Resolves#51318.
PR Close#51456
This commit adds runtime implementation of a basic preloading mechanism for defer blocks. The base prefetching logic invokes a dependency loading function (generated by the compiler) when a corresponding `prefetch when` condition is triggered. The `prefetch on` triggers would be implemented in followup PRs.
We plan to explore additional prefetching techniques and will followup with more PRs later (based on the research).
PR Close#51529
This commit adds an initial implementation of the `{#defer}` block runtime, which supports the `when` conditions. More conditions and basic prefetching support will be added in followup PRs.
PR Close#51347
Rather than the navigation transitions managing Router state, this
commit updates the Router to manage its own state based on ongoing
transition events. In the future, this can be abstracted even further to
have a totally separate class that manages the Router state. This would
allow the potential for swapping state manager implementations rather
than having to implement all types of state management in a single place.
One finding during tests was that unexpected errors thrown by the state management code moved
to the Router here will no longer be caught by the transition pipe's `catchError`.
This only includes calls to the following public Api methods:
* `go`, `replaceState`, `historyGo`, `isCurrentPathEqualTo` on `Location`
* `UrlSerializer.serialize`
* `UrlHandlingStrategy.merge`.
None of these methods should throw if the router is expected to function.
These might throw when tests include incomplete mocks, which is not
supported, or in cases where the actual browser methods like
`replaceState` would throw. This will already result in unexpected/unsupported
behavior. The failure case here is now arguably better - the navigation
itself still completes but the state update (either updating Router
internal state or updating the browser URL) fails separately and is
unhandled.
PR Close#48427
Updates the control flow tests to use the compiler instead of manually-written instructions. Also adds a couple of tests that I was using along the way to verify that things work as expected.
PR Close#51380
The runtime `ɵɵsetNgModuleScope` is modified to accept raw scope info as passed to it in local compilation mode. The runtime further registers the ng-module in the deps tracker. Then the runtime `ɵɵgetComponentDepsFactory` is implemented to use the deps tracker to get the component dependencies which leads to a valid and working Angular code.
PR Close#51377
The current logic requires that standalone component always provide an array of raw imports. But such array could be dropped from the downstream tools if the component has no imports. So it is more natural to allow undefined raw imports for standalone components and treat it as empty array.
PR Close#51377
Kristiyan Kostadinov