angular-cn/packages/core/src/render3/jit/pipe.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 {getCompilerFacade, JitCompilerUsage, R3PipeMetadataFacade} from '../../compiler/compiler_facade';
import {reflectDependencies} from '../../di/jit/util';
import {Type} from '../../interface/type';
import {Pipe} from '../../metadata/directives';
import {NG_FACTORY_DEF, NG_PIPE_DEF} from '../fields';

import {angularCoreEnv} from './environment';

export function compilePipe(type: Type<any>, meta: Pipe): void {
  let ngPipeDef: any = null;
  let ngFactoryDef: any = null;

  Object.defineProperty(type, NG_FACTORY_DEF, {
    get: () => {
      if (ngFactoryDef === null) {
        const metadata = getPipeMetadata(type, meta);
        const compiler = getCompilerFacade(
            {usage: JitCompilerUsage.Decorator, kind: 'pipe', type: metadata.type});
        ngFactoryDef = compiler.compileFactory(angularCoreEnv, `ng:///${metadata.name}/ɵfac.js`, {
          name: metadata.name,
          type: metadata.type,
          typeArgumentCount: 0,
          deps: reflectDependencies(type),
          target: compiler.FactoryTarget.Pipe
        });
      }
      return ngFactoryDef;
    },
    // Make the property configurable in dev mode to allow overriding in tests
    configurable: !!ngDevMode,
  });

  Object.defineProperty(type, NG_PIPE_DEF, {
    get: () => {
      if (ngPipeDef === null) {
        const metadata = getPipeMetadata(type, meta);
        const compiler = getCompilerFacade(
            {usage: JitCompilerUsage.Decorator, kind: 'pipe', type: metadata.type});
        ngPipeDef =
            compiler.compilePipe(angularCoreEnv, `ng:///${metadata.name}/ɵpipe.js`, metadata);
      }
      return ngPipeDef;
    },
    // Make the property configurable in dev mode to allow overriding in tests
    configurable: !!ngDevMode,
  });
}

function getPipeMetadata(type: Type<any>, meta: Pipe): R3PipeMetadataFacade {
  return {
    type: type,
    name: type.name,
    pipeName: meta.name,
    pure: meta.pure !== undefined ? meta.pure : true
  };
}