After the introduction of the view engine, we can drop a lot of code that is not used any more.
This should reduce the size of the app bundles because a lot of this code was not being properly tree-shaken by today's tools even though it was dead code.
The rationale of this change is to improve the inter-operability with web
components that might make use of the `<template>` tag.
DEPRECATION
The template tags and template attribute are deprecated:
<template ngFor [ngFor]=items let-item><li>...</li></template>
<li template="ngFor: let item of items">...</li>
should be rewritten as:
<ng-template ngFor [ngFor]=items let-item><li>...</li></ng-template>
Note that they still be supported in 4.x with a deprecartion warning in
development mode.
MIGRATION
- `template` tags (or elements with a `template` attribute) should be rewritten
as a `ng-template` tag,
- `ng-content` selectors should be updated to referto a `ng-template` where they
use to refer to a template: `<ng-content selector="template[attr]">` should be
rewritten as `<ng-content selector="ng-template[attr]">`
- if you consume a component relying on your templates being actual `template`
elements (that is they include a `<ng-content selector="template[attr]">`). You
should still migrate to `ng-template` and make use of `ngProjectAs` to override
the way `ng-content` sees the template:
`<ng-template projectAs="template[attr]">`
- while `template` elements are deprecated in 4.x they continue to work.
Included refactoring:
- splits the `RendererV2` into a `RendererFactoryV2` and a `RendererV2`
- makes the `DebugRendererV2` a private class in `@angular/core`
- remove `setBindingDebugInfo` from `RendererV2`, but rename `RendererV2.setText` to
`RendererV2.setValue` and allow it on comments and text nodes.
Part of #14013
Included refactoring:
- make ViewData.parentIndex point to component provider index
- split NodeType.Provider into Provider / Directive / Pipe
- make purePipe take the real pipe as argument to detect changes
- order change detection:
1) directive props
2) renderer props
Part of #14013
PR Close#14412
Detailed changes:
- remove `UNINITIALIZED`, initialize change detection fields with `undefined`.
* we use `view.numberOfChecks === 0` now everywhere
as indicator whether we are in the first change detection cycle
(previously we used this only in a couple of places).
* we keep the initialization itself as change detection get slower without it.
- remove passing around `throwOnChange` in various generated calls,
and store it on the view as property instead.
- change generated code for bindings to DOM elements as follows:
Before:
```
var currVal_10 = self.context.bgColor;
if (jit_checkBinding15(self.throwOnChange,self._expr_10,currVal_10)) {
self.renderer.setElementStyle(self._el_0,'backgroundColor',((self.viewUtils.sanitizer.sanitize(jit_21,currVal_10) == null)? null: self.viewUtils.sanitizer.sanitize(jit_21,currVal_10).toString()));
self._expr_10 = currVal_10;
}
var currVal_11 = jit_inlineInterpolate16(1,' ',self.context.data.value,' ');
if (jit_checkBinding15(self.throwOnChange,self._expr_11,currVal_11)) {
self.renderer.setText(self._text_1,currVal_11);
self._expr_11 = currVal_11;
}
```,
After:
```
var currVal_10 = self.context.bgColor;
jit_checkRenderStyle14(self,self._el_0,'backgroundColor',null,self._expr_10,self._expr_10=currVal_10,false,jit_21);
var currVal_11 = jit_inlineInterpolate15(1,' ',self.context.data.value,' ');
jit_checkRenderText16(self,self._text_1,self._expr_11,self._expr_11=currVal_11,false);
```
Performance impact:
- None seen (checked against internal latency lab)
Part of #13651
Note: This checks the constructors of `@Injectable` classes more strictly.
E.g this will fail now as the constructor argument has no `@Inject` nor is
the type of the argument a DI token.
```
@Injectable()
class MyService {
constructor(dep: string) {}
}
```
Last part of #12787Closes#12787
Removes `CompileIdentifierMetadata.name` / `.moduleUrl`,
as well as `CompileTypeMetadata.name / moduleUrl` and
`CompileFactoryMetadata.name / moduleUrl`.
Previously, if a `TemplateRef` was created in a `ViewContainerRef`
at a different place, the content was not query able at all.
With this change, the content of the template can be queried
as if it was stamped out at the declaration place of the template.
E.g. in the following example, the `QueryList<ChildCmp>` will
be filled once the button is clicked.
```
@Component({
selector: ‘my-comp’,
template: ‘<button #vc (click)=“createView()”></button>’
})
class MyComp {
@ContentChildren(ChildCmp)
children: QueryList<ChildCmp>;
@ContentChildren(TemplateRef)
template: TemplateRef;
@ViewChild(‘vc’, {read: ViewContainerRef})
vc: ViewContainerRef;
createView() {
this.vc.createEmbeddedView(this.template);
}
}
@Component({
template: `
<my-comp>
<template><child-cmp></child-cmp></template>
</my-comp>
`
})
class App {}
```
Closes#12283Closes#12094
This fixes a performance regressions introduced by 178fb79b5cafe36c993bb1f9f9a63e8bac162c66.
Also makes properties in the directive wrapper private
so that closure compiler can minify them better.
