0c3738a780
This commit adds support for templateUrl in component templates within ngtsc. The compilation pipeline is split into sync and async versions, where asynchronous compilation invokes a special preanalyze() phase of analysis. The preanalyze() phase can optionally return a Promise which will delay compilation until it resolves. A ResourceLoader interface is used to resolve templateUrls to template strings and can return results either synchronously or asynchronously. During sync compilation it is an error if the ResourceLoader returns a Promise. Two ResourceLoader implementations are provided. One uses 'fs' to read resources directly from disk and is chosen if the CompilerHost doesn't provide a readResource method. The other wraps the readResource method from CompilerHost if it's provided. PR Close #24704
60 lines
1.5 KiB
TypeScript
60 lines
1.5 KiB
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import * as fs from 'fs';
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import {ResourceLoader} from './annotations';
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/**
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* `ResourceLoader` which delegates to a `CompilerHost` resource loading method.
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*/
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export class HostResourceLoader implements ResourceLoader {
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private cache = new Map<string, string>();
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private fetching = new Set<string>();
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constructor(private host: (url: string) => string | Promise<string>) {}
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preload(url: string): Promise<void>|undefined {
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if (this.cache.has(url) || this.fetching.has(url)) {
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return undefined;
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}
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const result = this.host(url);
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if (typeof result === 'string') {
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this.cache.set(url, result);
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return undefined;
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} else {
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this.fetching.add(url);
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return result.then(str => {
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this.fetching.delete(url);
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this.cache.set(url, str);
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});
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}
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}
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load(url: string): string {
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if (this.cache.has(url)) {
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return this.cache.get(url) !;
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}
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const result = this.host(url);
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if (typeof result !== 'string') {
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throw new Error(`HostResourceLoader: host(${url}) returned a Promise`);
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}
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this.cache.set(url, result);
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return result;
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}
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}
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/**
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* `ResourceLoader` which directly uses the filesystem to resolve resources synchronously.
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*/
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export class FileResourceLoader implements ResourceLoader {
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load(url: string): string { return fs.readFileSync(url, 'utf8'); }
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}
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