angular-docs-cn/packages/compiler/src/render3/partial/api.ts

/**
 * @license
 * Copyright Google LLC 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 * as o from '../../output/output_ast';

/**
 * This interface describes the shape of the object that partial directive declarations are compiled
 * into. This serves only as documentation, as conformance of this interface is not enforced during
 * the generation of the partial declaration, nor when the linker applies full compilation from the
 * partial declaration.
 */
export interface R3DeclareDirectiveMetadata {
  /**
   * Version number of the metadata format. This is used to evolve the metadata
   * interface later - the linker will be able to detect which version a library
   * is using and interpret its metadata accordingly.
   */
  version: 1;

  /**
   * Unparsed selector of the directive.
   */
  selector?: string;

  /**
   * Reference to the directive class itself.
   */
  type: o.Expression;

  /**
   * A mapping of inputs from class property names to binding property names, or to a tuple of
   * binding property name and class property name if the names are different.
   */
  inputs?: {[classPropertyName: string]: string|[string, string]};

  /**
   * A mapping of outputs from class property names to binding property names, or to a tuple of
   * binding property name and class property name if the names are different.
   */
  outputs?: {[classPropertyName: string]: string};

  /**
   * Information about host bindings present on the component.
   */
  host?: {
    /**
     * A mapping of attribute names to their value expression.
     */
    attributes?: {[key: string]: o.Expression};

    /**
     * A mapping of event names to their unparsed event handler expression.
     */
    listeners: {[key: string]: string};

    /**
     * A mapping of bound properties to their unparsed binding expression.
     */
    properties?: {[key: string]: string};

    /**
     * The value of the class attribute, if present. This is stored outside of `attributes` as its
     * string value must be known statically.
     */
    classAttribute?: string;

    /**
     * The value of the style attribute, if present. This is stored outside of `attributes` as its
     * string value must be known statically.
     */
    styleAttribute?: string;
  };

  /**
   * Information about the content queries made by the directive.
   */
  queries?: R3DeclareQueryMetadata[];

  /**
   * Information about the view queries made by the directive.
   */
  viewQueries?: R3DeclareQueryMetadata[];

  /**
   * The list of providers provided by the directive.
   */
  providers?: o.Expression;

  /**
   * The names by which the directive is exported.
   */
  exportAs?: string[];

  /**
   * Whether the directive has an inheritance clause. Defaults to false.
   */
  usesInheritance?: boolean;

  /**
   * Whether the directive implements the `ngOnChanges` hook. Defaults to false.
   */
  usesOnChanges?: boolean;

  /**
   * A reference to the `@angular/core` ES module, which allows access
   * to all Angular exports, including Ivy instructions.
   */
  ngImport: o.Expression;
}

export interface R3DeclareQueryMetadata {
  /**
   * 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. Defaults to false.
   */
  first?: boolean;

  /**
   * Either an expression representing a type or `InjectionToken` for the query
   * predicate, or a set of string selectors.
   */
  predicate: o.Expression|string[];

  /**
   * Whether to include only direct children or all descendants. Defaults to false.
   */
  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;

  /**
   * Whether or not this query should collect only static results. Defaults to false.
   *
   * 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;
}