The content projection mechanism is static, in that it only looks at the static
template nodes before directives are matched and change detection is run.
When you have a selector-based content projection the selection is based
on nodes that are available in the template.
For example:
```
<ng-content selector="[some-attr]"></ng-content>
```
would match
```
<div some-attr="..."></div>
```
If you have an inline-template in your projected nodes. For example:
```
<div *ngIf="..." some-attr="..."></div>
```
This gets pre-parsed and converted to a canonical form.
For example:
```
<ng-template [ngIf]="...">
<div some-attr=".."></div>
</ng-template>
```
Note that only structural attributes (e.g. `*ngIf`) stay with the `<ng-template>`
node. The other attributes move to the contained element inside the template.
When this happens in ivy, the ng-template content is removed
from the component template function and is compiled into its own
template function. But this means that the information about the
attributes that were on the content are lost and the projection
selection mechanism is unable to match the original
`<div *ngIf="..." some-attr>`.
This commit adds support for this in ivy. Attributes are separated into three
groups (Bindings, Templates and "other"). For inline-templates the Bindings
and "other" types are hoisted back from the contained node to the `template()`
instruction, so that they can be used in content projection matching.
PR Close#29041
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 change we only checked whether current lView has a next pointer while traversing tNode tree. However in some cases this pointer can be undefined and we need to look up parents chain to find suitable next pointer. This commit adds the logic of searching for the next pointer taking parents chain into account.
PR Close#28533
Prior to this change `viewQuery` functions that represent @ViewQuery list were not composable, which caused problems in case one Component/Directive inherits another one and both of them contain View Queries. Due to the fact that we used indices to reference queries, resulting query set was corrupted (child component queries were overridden by super class ones). In order to avoid that we no longer use indices assigned at compile time and instead maintain current view query index while iterating through them. This allows us to compose `viewQuery` functions and make inheritance feature work with View Queries.
PR Close#28309
This PR assures that content projection works if an <ng-content> tag is
placed inside an <ng-template> in one component and that <ng-template>
is inserted into a different component. It fixes a bug where the
projection instruction code would walk up the insertion tree to find
selector data instead of the declaration tree.
PR Close#27783
Prior to this change, we were unable to match directives using `ng-template` tags (for example the following selector would not work even though there might be some <ng-template>s in a template: `ng-template[directiveA]`. As a result, that broke some components that relies on such selectors to work. In order to resolve the problem, we now pass tag name to the `template` instruction (where we passed `null` before) and this tag name is used for matching at runtime. This update should also help support projecting containers, because the tag name is required to properly match such elements.
PR Close#27636
NOTE: This does NOT add parsing of namespaced attributes
- Adds AttributeMarker for namespaced attributes
- Adds test for namespaced attributes
- Updates AttributeMarker enum to use CamelCase, and not UPPER_CASE names
PR Close#24386
In ngIvy directives matching (determining which directives are active based
on a CSS seletor) happens at runtime. This means that runtime needs to have
enough context to match directives. This PR takes care of cases where a directive's
selector should match bindings (ex. [foo]="exp") and event handlers (ex. (out)="do()").
In the mentioned cases we need to have binding / output "attributes" for directive's
CSS selector matching purposes. At the same time those are not regular attributes and
as such should not be reflected in the DOM.
Closes#23706
PR Close#23991
Remove `containerRefreshStart` and `containerRefreshEnd` instruction
from the output.
Generate directives as a list in `componentDef` rather than inline into
instructions. This is consistent in making selector resolution runtime
so that translation of templates can follow locality.
PR Close#22921
By adding attributes on the <ng-content> element template authors
can decide how content should be re-projected (or, in other words:
which selectors should match re-projected content).
PR Close#21935
This change makes the code cleaner for the user. It does mean
a little bit more work for us since we have to patch the `type` back
into the `DirectiveDef`. However since the patching happens only once
on startup it should not be significant.
PR Close#21374