Alex Rickabaugh b381497126 feat(ngcc): add a migration for undecorated child classes (#33362)
In Angular View Engine, there are two kinds of decorator inheritance:

1) both the parent and child classes have decorators

This case is supported by InheritDefinitionFeature, which merges some fields
of the definitions (such as the inputs or queries).

2) only the parent class has a decorator

If the child class is missing a decorator, the compiler effectively behaves
as if the parent class' decorator is applied to the child class as well.
This is the "undecorated child" scenario, and this commit adds a migration
to ngcc to support this pattern in Ivy.

This migration has 2 phases. First, the NgModules of the application are
scanned for classes in 'declarations' which are missing decorators, but
whose base classes do have decorators. These classes are the undecorated
children. This scan is performed recursively, so even if a declared class
has a base class that itself inherits a decorator, this case is handled.

Next, a synthetic decorator (either @Component or @Directive) is created
on the child class. This decorator copies some critical information such
as 'selector' and 'exportAs', as well as supports any decorated fields
(@Input, etc). A flag is passed to the decorator compiler which causes a
special feature `CopyDefinitionFeature` to be included on the compiled
definition. This feature copies at runtime the remaining aspects of the
parent definition which `InheritDefinitionFeature` does not handle,
completing the "full" inheritance of the child class' decorator from its
parent class.

PR Close #33362
2019-10-25 09:16:50 -07:00

277 lines
7.3 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {ChangeDetectionStrategy, ViewEncapsulation} from '../../core';
import {InterpolationConfig} from '../../ml_parser/interpolation_config';
import * as o from '../../output/output_ast';
import {ParseSourceSpan} from '../../parse_util';
import * as t from '../r3_ast';
import {R3DependencyMetadata} from '../r3_factory';
/**
* Information needed to compile a directive for the render3 runtime.
*/
export interface R3DirectiveMetadata {
/**
* Name of the directive type.
*/
name: string;
/**
* An expression representing a reference to the directive itself.
*/
type: o.Expression;
/**
* Number of generic type parameters of the type itself.
*/
typeArgumentCount: number;
/**
* A source span for the directive type.
*/
typeSourceSpan: ParseSourceSpan;
/**
* Dependencies of the directive's constructor.
*/
deps: R3DependencyMetadata[]|null;
/**
* Unparsed selector of the directive, or `null` if there was no selector.
*/
selector: string|null;
/**
* Information about the content queries made by the directive.
*/
queries: R3QueryMetadata[];
/**
* Information about the view queries made by the directive.
*/
viewQueries: R3QueryMetadata[];
/**
* Mappings indicating how the directive interacts with its host element (host bindings,
* listeners, etc).
*/
host: R3HostMetadata;
/**
* Information about usage of specific lifecycle events which require special treatment in the
* code generator.
*/
lifecycle: {
/**
* Whether the directive uses NgOnChanges.
*/
usesOnChanges: boolean;
};
/**
* A mapping of input field names to the property names.
*/
inputs: {[field: string]: string | [string, string]};
/**
* A mapping of output field names to the property names.
*/
outputs: {[field: string]: string};
/**
* Whether or not the component or directive inherits from another class
*/
usesInheritance: boolean;
/**
* Whether or not the component or directive inherits its entire decorator from its base class.
*/
fullInheritance: boolean;
/**
* Reference name under which to export the directive's type in a template,
* if any.
*/
exportAs: string[]|null;
/**
* The list of providers defined in the directive.
*/
providers: o.Expression|null;
}
/**
* Information needed to compile a component for the render3 runtime.
*/
export interface R3ComponentMetadata extends R3DirectiveMetadata {
/**
* Information about the component's template.
*/
template: {
/**
* Parsed nodes of the template.
*/
nodes: t.Node[];
};
/**
* A map of pipe names to an expression referencing the pipe type which are in the scope of the
* compilation.
*/
pipes: Map<string, o.Expression>;
/**
* A list of directive selectors and an expression referencing the directive type which are in the
* scope of the compilation.
*/
directives: {selector: string, expression: o.Expression}[];
/**
* Whether to wrap the 'directives' and/or `pipes` array, if one is generated, in a closure.
*
* This is done when the directives or pipes contain forward references.
*/
wrapDirectivesAndPipesInClosure: boolean;
/**
* A collection of styling data that will be applied and scoped to the component.
*/
styles: string[];
/**
* An encapsulation policy for the template and CSS styles. One of:
* - `ViewEncapsulation.Native`: Use shadow roots. This works only if natively available on the
* platform (note that this is marked the as the "deprecated shadow DOM" as of Angular v6.1.
* - `ViewEncapsulation.Emulated`: Use shimmed CSS that emulates the native behavior.
* - `ViewEncapsulation.None`: Use global CSS without any encapsulation.
* - `ViewEncapsulation.ShadowDom`: Use the latest ShadowDOM API to natively encapsulate styles
* into a shadow root.
*/
encapsulation: ViewEncapsulation;
/**
* A collection of animation triggers that will be used in the component template.
*/
animations: o.Expression|null;
/**
* The list of view providers defined in the component.
*/
viewProviders: o.Expression|null;
/**
* Path to the .ts file in which this template's generated code will be included, relative to
* the compilation root. This will be used to generate identifiers that need to be globally
* unique in certain contexts (such as g3).
*/
relativeContextFilePath: string;
/**
* Whether translation variable name should contain external message id
* (used by Closure Compiler's output of `goog.getMsg` for transition period).
*/
i18nUseExternalIds: boolean;
/**
* Overrides the default interpolation start and end delimiters ({{ and }}).
*/
interpolation: InterpolationConfig;
/**
* Strategy used for detecting changes in the component.
*/
changeDetection?: ChangeDetectionStrategy;
}
/**
* Information needed to compile a query (view or content).
*/
export interface R3QueryMetadata {
/**
* Name of the property on the class to update with query results.
*/
propertyName: string;
/**
* Whether to read only the first matching result, or an array of results.
*/
first: boolean;
/**
* Either an expression representing a type for the query predicate, or a set of string selectors.
*/
predicate: o.Expression|string[];
/**
* Whether to include only direct children or all descendants.
*/
descendants: boolean;
/**
* An expression representing a type to read from each matched node, or null if the default value
* for a given node is to be returned.
*/
read: o.Expression|null;
/**
* Whether or not this query should collect only static results.
*
* If static is true, the query's results will be set on the component after nodes are created,
* but before change detection runs. This means that any results that relied upon change detection
* to run (e.g. results inside *ngIf or *ngFor views) will not be collected. Query results are
* available in the ngOnInit hook.
*
* If static is false, the query's results will be set on the component after change detection
* runs. This means that the query results can contain nodes inside *ngIf or *ngFor views, but
* the results will not be available in the ngOnInit hook (only in the ngAfterContentInit for
* content hooks and ngAfterViewInit for view hooks).
*/
static: boolean;
}
/**
* Output of render3 directive compilation.
*/
export interface R3DirectiveDef {
expression: o.Expression;
type: o.Type;
}
/**
* Output of render3 component compilation.
*/
export interface R3ComponentDef {
expression: o.Expression;
type: o.Type;
}
/**
* Mappings indicating how the class interacts with its
* host element (host bindings, listeners, etc).
*/
export interface R3HostMetadata {
/**
* A mapping of attribute binding keys to `o.Expression`s.
*/
attributes: {[key: string]: o.Expression};
/**
* A mapping of event binding keys to unparsed expressions.
*/
listeners: {[key: string]: string};
/**
* A mapping of property binding keys to unparsed expressions.
*/
properties: {[key: string]: string};
specialAttributes: {styleAttr?: string; classAttr?: string;};
}