In Angular today, the following pattern works:
```typescript
export class BaseDir {
constructor(@Inject(ViewContainerRef) protected vcr: ViewContainerRef) {}
}
@Directive({
selector: '[child]',
})
export class ChildDir extends BaseDir {
// constructor inherited from BaseDir
}
```
A decorated child class can inherit a constructor from an undecorated base
class, so long as the base class has metadata of its own (for JIT mode).
This pattern works regardless of metadata in AOT.
In Angular Ivy, this pattern does not work: without the @Directive
annotation identifying the base class as a directive, information about its
constructor parameters will not be captured by the Ivy compiler. This is a
result of Ivy's locality principle, which is the basis behind a number of
compilation optimizations.
As a solution, @Directive() without a selector will be interpreted as a
"directive base class" annotation. Such a directive cannot be declared in an
NgModule, but can be inherited from. To implement this, a few changes are
made to the ngc compiler:
* the error for a selector-less directive is now generated when an NgModule
declaring it is processed, not when the directive itself is processed.
* selector-less directives are not tracked along with other directives in
the compiler, preventing other errors (like their absence in an NgModule)
from being generated from them.
PR Close#31379
In Angular today, the following pattern works:
```typescript
export class BaseDir {
constructor(@Inject(ViewContainerRef) protected vcr: ViewContainerRef) {}
}
@Directive({
selector: '[child]',
})
export class ChildDir extends BaseDir {
// constructor inherited from BaseDir
}
```
A decorated child class can inherit a constructor from an undecorated base
class, so long as the base class has metadata of its own (for JIT mode).
This pattern works regardless of metadata in AOT.
In Angular Ivy, this pattern does not work: without the @Directive
annotation identifying the base class as a directive, information about its
constructor parameters will not be captured by the Ivy compiler. This is a
result of Ivy's locality principle, which is the basis behind a number of
compilation optimizations.
As a solution, @Directive() without a selector will be interpreted as a
"directive base class" annotation. Such a directive cannot be declared in an
NgModule, but can be inherited from. To implement this, a few changes are
made to the ngc compiler:
* the error for a selector-less directive is now generated when an NgModule
declaring it is processed, not when the directive itself is processed.
* selector-less directives are not tracked along with other directives in
the compiler, preventing other errors (like their absence in an NgModule)
from being generated from them.
PR Close#31379
As part of FW-1265, the `@angular/compiler` package is made compatible
with the TypeScript `--strict` flag. This already unveiled a few bugs,
so the strictness flag seems to help with increasing the overall code health.
Read more about the strict flag [here](https://www.typescriptlang.org/docs/handbook/compiler-options.html)
PR Close#30993
This commit fixes a couple of issues with TS 3.5 compatibility in order to
unblock migration of g3. Mostly 'any's are added, and there are no behavior
changes.
PR Close#31174
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
This adds compilation of @NgModule providers and imports into
ngInjectorDef statements in generated code. All @NgModule annotations
will be compiled and the @NgModule decorators removed from the
resultant js output.
All @Injectables will also be compiled in Ivy mode, and the decorator
removed.
PR Close#22458
Rename @Injectable({scope -> providedIn}).
Instead of {providedIn: APP_ROOT_SCOPE}, accept {providedIn: 'root'}.
Also, {providedIn: null} implies the injectable should not be added
to any scope.
PR Close#22655
This commit bundles 3 important changes, with the goal of enabling tree-shaking
of services which are never injected. Ordinarily, this tree-shaking is prevented
by the existence of a hard dependency on the service by the module in which it
is declared.
Firstly, @Injectable() is modified to accept a 'scope' parameter, which points
to an @NgModule(). This reverses the dependency edge, permitting the module to
not depend on the service which it "provides".
Secondly, the runtime is modified to understand the new relationship created
above. When a module receives a request to inject a token, and cannot find that
token in its list of providers, it will then look at the token for a special
ngInjectableDef field which indicates which module the token is scoped to. If
that module happens to be in the injector, it will behave as if the token
itself was in the injector to begin with.
Thirdly, the compiler is modified to read the @Injectable() metadata and to
generate the special ngInjectableDef field as part of TS compilation, using the
PartialModules system.
Additionally, this commit adds several unit and integration tests of various
flavors to test this change.
PR Close#22005
Structural directives can now specify a type guard that describes
what types can be inferred for an input expression inside the
directive's template.
NgIf was modified to declare an input guard on ngIf.
After this change, `fullTemplateTypeCheck` will infer that
usage of `ngIf` expression inside it's template is truthy.
For example, if a component has a property `person?: Person`
and a template of `<div *ngIf="person"> {{person.name}} </div>`
the compiler will no longer report that `person` might be null or
undefined.
The template compiler will generate code similar to,
```
if (NgIf.ngIfTypeGuard(instance.person)) {
instance.person.name
}
```
to validate the template's use of the interpolation expression.
Calling the type guard in this fashion allows TypeScript to infer
that `person` is non-null.
Fixes: #19756?
PR Close#20702
Added the compiler options `strictInjectionParameters` that defaults
to `false`. If enabled the compiler will report errors for parameters
of an `@Injectable` that cannot be determined instead of generating a
warning.
This is planned to be switched to default to `true` for Angular 6.0.
We now create 2 programs with exactly the same fileNames and
exactly the same `import` / `export` declarations,
allowing TS to reuse the structure of first program
completely. When passing in an oldProgram and the files didn’t change,
TS can also reuse the old program completely.
This is possible buy adding generated files to TS
in `host.geSourceFile` via `ts.SourceFile.referencedFiles`.
This commit also:
- has a minor side effect on how we generate shared stylesheets:
- previously every import in a stylesheet would generate a new
`.ngstyles.ts` file.
- now, we only generate 1 `.ngstyles.ts` file per entry in `@Component.styleUrls`.
This was required as we need to be able to determine the program files
without loading the resources (which can be async).
- makes all angular related methods in `CompilerHost`
optional, allowing to just use a regular `ts.CompilerHost` as `CompilerHost`.
- simplifies the logic around `Compiler.analyzeNgModules` by introducing `NgAnalyzedFile`.
Perf impact: 1.5s improvement in compiling angular io
PR Close#19275
This speeds up the compilation process significantly.
Also introduces a new option `fullTemplateTypeCheck` to do more checks in templates:
- check expressions inside of templatized content (e.g. inside of `<div *ngIf>`).
- check the arguments of calls to the `transform` function of pipes
- check references to directives that were exposed as variables via `exportAs`
PR Close#19152
After this, neither @angular/compiler nor @angular/comnpiler-cli depend
on @angular/core.
This add a duplication of some interfaces and enums which is stored
in @angular/compiler/src/core.ts
BREAKING CHANGE:
- `@angular/platform-server` now additionally depends on
`@angular/platform-browser-dynamic` as a peer dependency.
PR Close#18683
Allows to inherit ctor args, lifecycle hooks and statics from a class
in another compilation unit.
Will error if trying to inherit from a class in another compilation unit
that has an `@Component` / `@Directive` / `@Pipe` / `@NgModule`.
`ngc` would look for flat module resources relative to the flat module index.
`ngc` now looks for flat module resources relative to the `.d.ts` file that declarates
the component.
Fixes#15221
PR Close#15367
Closure compiler is very sensitive to top level function calls.
This commit makes the function calls `createComponentFactory`
and `createRendererTypeV2` logic-less.
Fixes#15181
PR Close#15214
DEPRECATION:
- the arguments `inputs` / `outputs` / `ngContentSelectors` of `downgradeComponent`
are no longer used as Angular calculates these automatically now.
- Compiler.getNgContentSelectors is deprecated. Use
ComponentFactory.ngContentSelectors instead.
E.g. for a component like this:
```
@Component({
template: ‘<ng-content select=“child”></ng-content>’
})
class MyComp {
@Input(‘aInputName’)
aInputProp: string;
@Output(‘aEventName’)
aOuputProp: EventEmitter<any>;
}
```
the `ComponentFactory` will now contain the following:
- `inputs = {aInputProp: ‘aInputName’}`
- `outputs = {aOutputProp: ‘aOutputName’}`
- `ngContentSelectors = [‘child’]`
DEPRECATION:
- the arguments `inputs` / `outputs` / `ngContentSelectors` of `downgradeComponent`
are no longer used as Angular calculates these automatically now.
- Compiler.getNgContentSelectors is deprecated. Use
ComponentFactory.ngContentSelectors instead.
E.g. for a component like this:
```
@Component({
template: ‘<ng-content select=“child”></ng-content>’
})
class MyComp {
@Input(‘aInputName’)
aInputProp: string;
@Output(‘aEventName’)
aOuputProp: EventEmitter<any>;
}
```
the `ComponentFactory` will now contain the following:
- `inputs = {aInputProp: ‘aInputName’}`
- `outputs = {aOutputProp: ‘aOutputName’}`
- `ngContentSelectors = [‘child’]`
In v2.x, users had to annotate classes that they intended to use as tokens with `@Injectable`. This is no longer required in v4.x for tokens,
and we now require the constructor parameters of classes annotated
with `@Injectable` to be statically analyzable by ngc.
This commit reduces the error into a warning
if the constructor parameters do not meet this condition.
DEPRECATION:
- Classes annotated with `@Injectable` but whose constructor’s parameter types
are not statically analyzable by ngc will produce a warning.
Closes#15003
Currently, it says:
Unexpected value 'FuzzyTimePipe in
javascript/angular2/example/search/fuzzy_time.ts' declared by the module
'SearchModule in javascript/angular2/example/search/search_module.ts'
The new error message also suggests: 'Please add a @Pipe/@Directive/@Component annotation.'
The main use case for the generated source maps is to give
errors a meaningful context in terms of the original source
that the user wrote.
Related changes that are included in this commit:
* renamed virtual folders used for jit:
* ng://<module type>/module.ngfactory.js
* ng://<module type>/<comp type>.ngfactory.js
* ng://<module type>/<comp type>.html (for inline templates)
* error logging:
* all errors that happen in templates are logged
from the place of the nearest element.
* instead of logging error messages and stacks separately,
we log the actual error. This is needed so that browsers apply
source maps to the stack correctly.
* error type and error is logged as one log entry.
Note that long-stack-trace zone has a bug that
disables source maps for stack traces,
see https://github.com/angular/zone.js/issues/661.
BREAKING CHANGE:
- DebugNode.source no more returns the source location of a node.
Closes 14013
Danny Skoog
Alex Rickabaugh
Kara Erickson
Paul Gschwendtner
Keen Yee Liau
Victor Berchet
John Papa
Chuck Jazdzewski
Tobias Bosch
Pawel Kozlowski
Miško Hevery
Bowen Ni
Jason Aden