Before this change ngIvy implementation of queries would throw upon
encountering null / undefined query result collected from an embedded
view. It turns out that we might have a provider that explicitly provides
a null / undefined value in a place of a token queried for.
This commit removes a check from the ngIvy query implementation that was
asserting on a query result to be defined.
Fixes#35673
PR Close#35796
Before this change content queries with the `descendants: false` option, as implemented in ivy,
would not descendinto `<ng-container>` elements. This behaviour was different from the way the
View Engine worked. This change alligns ngIvy and VE behaviours when it comes to queries and the
`<ng-container>` elements and fixes a common bugs where a query target was placed inside the
`<ng-container>` element with a * directive on it.
Before:
```html
<needs-target>
<ng-container *ngIf="condition">
<div #target>...</div> <!-- this node would NOT match -->
</ng-container>
</needs-target>
```
After:
```html
<needs-target>
<ng-container *ngIf="condition">
<div #target>...</div> <!-- this node WILL match -->
</ng-container>
</needs-target>
```
Fixes#34768
PR Close#35384
Child component refresh must happen before executing the ViewQueryFn because
child components could insert a template from the host that contains the result
of the ViewQuery function (see related test added in this PR).
PR Close#32922
Fixes view and content queries not being inherited in Ivy, if the base class hasn't been annotated with an Angular decorator (e.g. `Component` or `Directive`).
Also reworks the way the `ngBaseDef` is created so that it is added at the same point as the queries, rather than inside of the `Input` and `Output` decorators.
This PR partially resolves FW-1275. Support for host bindings will be added in a follow-up, because this PR is somewhat large as it is.
PR Close#30015
In View Engine, we used to generate empty QueryLists for content queries on root
components (though we did not actually support populating these lists). We need
to keep this behavior in Ivy for backwards compatibility. Otherwise, components
that are sometimes used as root will fail if they are relying on content query
results to always be defined.
PR Close#29514
BREAKING CHANGE:
Certain elements (like `<tr>` or `<col>`) require parent elements to be of a certain type by the HTML specification
(ex. <tr> can only be inside <tbody> / <thead>). Before this change Angular template parser was auto-correcting
"invalid" HTML using the following rules:
- `<tr>` would be wrapped in `<tbody>` if not inside `<tbody>`, `<tfoot>` or `<thead>`;
- `<col>` would be wrapped in `<colgroup>` if not inside `<colgroup>`.
This meachanism of automatic wrapping / auto-correcting was problematic for several reasons:
- it is non-obvious and arbitrary (ex. there are more HTML elements that has rules for parent type);
- it is incorrect for cases where `<tr>` / `<col>` are at the root of a component's content, ex.:
```html
<projecting-tr-inside-tbody>
<tr>...</tr>
</projecting-tr-inside-tbody>
```
In the above example the `<projecting-tr-inside-tbody>` component culd be "surprised" to see additional
`<tbody>` elements inserted by Angular HTML parser.
PR Close#29219
This commit adds support for the `static: true` flag in `ContentChild`
queries. Prior to this commit, all `ContentChild` queries were resolved
after change detection ran. This is a problem for backwards
compatibility because View Engine also supported "static" queries which
would resolve before change detection.
Now if users add a `static: true` option, the query will be resolved in
creation mode (before change detection runs). For example:
```ts
@ContentChild(TemplateRef, {static: true}) template !: TemplateRef;
```
This feature will come in handy for components that need
to create components dynamically.
PR Close#28811
This commit adds support for the `static: true` flag in
`ViewChild` queries. Prior to this commit, all `ViewChild`
queries were resolved after change detection ran. This is
a problem for backwards compatibility because View Engine
also supported "static" queries which would resolve before
change detection.
Now if users add a `static: true` option, the query will be
resolved in creation mode (before change detection runs).
For example:
```ts
@ViewChild(TemplateRef, {static: true}) template !: TemplateRef;
```
This feature will come in handy for components that need
to create components dynamically.
PR Close#28811
Prior to this commit, the timing of `ViewChild`/`ContentChild` query
resolution depended on the results of each query. If any results
for a particular query were nested inside embedded views (e.g.
*ngIfs), that query would be resolved after change detection ran.
Otherwise, the query would be resolved as soon as nodes were created.
This inconsistency in resolution timing had the potential to cause
confusion because query results would sometimes be available in
ngOnInit, but sometimes wouldn't be available until ngAfterContentInit
or ngAfterViewInit. Code depending on a query result could suddenly
stop working as soon as an *ngIf or an *ngFor was added to the template.
With this commit, users can dictate when they want a particular
`ViewChild` or `ContentChild` query to be resolved with the `static`
flag. For example, one can mark a particular query as `static: false`
to ensure change detection always runs before its results are set:
```ts
@ContentChild('foo', {static: false}) foo !: ElementRef;
```
This means that even if there isn't a query result wrapped in an
*ngIf or an *ngFor now, adding one to the template later won't change
the timing of the query resolution and potentially break your component.
Similarly, if you know that your query needs to be resolved earlier
(e.g. you need results in an ngOnInit hook), you can mark it as
`static: true`.
```ts
@ViewChild(TemplateRef, {static: true}) foo !: TemplateRef;
```
Note: this means that your component will not support *ngIf results.
If you do not supply a `static` option when creating your `ViewChild` or
`ContentChild` query, the default query resolution timing will kick in.
Note: This new option only applies to `ViewChild` and `ContentChild`
queries, not `ViewChildren` or `ContentChildren` queries, as those types
already resolve after CD runs.
PR Close#28810
Prior to this change in Ivy we had strict check that disabled non-unique #localRefs usage within a given template. While this limitation was technically present in View Engine, in many cases View Engine neglected this restriction and as a result, some apps relied on a fact that multiple non-unique #localRefs can be defined and utilized to query elements via @ViewChild(ren) and @ContentChild(ren). In order to provide better compatibility with View Engine, this commit removes existing restriction.
As a part of this commit, are few tests were added to verify VE and Ivy compatibility in most common use-cases where multiple non-unique #localRefs were used.
PR Close#28627
Pawel Kozlowski
crisbeto
Andrew Scott
Kara Erickson
Paul Gschwendtner
Andrew Kushnir