angular-docs-cn/modules/@angular/compiler/src/style_url_resolver.ts

48 lines
1.7 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
*/
// Some of the code comes from WebComponents.JS
// https://github.com/webcomponents/webcomponentsjs/blob/master/src/HTMLImports/path.js
import {UrlResolver} from './url_resolver';
export class StyleWithImports {
constructor(public style: string, public styleUrls: string[]) {}
}
export function isStyleUrlResolvable(url: string): boolean {
if (url == null || url.length === 0 || url[0] == '/') return false;
const schemeMatch = url.match(URL_WITH_SCHEMA_REGEXP);
return schemeMatch === null || schemeMatch[1] == 'package' || schemeMatch[1] == 'asset';
}
/**
* Rewrites stylesheets by resolving and removing the @import urls that
* are either relative or don't have a `package:` scheme
*/
export function extractStyleUrls(
resolver: UrlResolver, baseUrl: string, cssText: string): StyleWithImports {
const foundUrls: string[] = [];
const modifiedCssText =
cssText.replace(CSS_COMMENT_REGEXP, '').replace(CSS_IMPORT_REGEXP, (...m: string[]) => {
const url = m[1] || m[2];
if (!isStyleUrlResolvable(url)) {
// Do not attempt to resolve non-package absolute URLs with URI scheme
return m[0];
}
foundUrls.push(resolver.resolve(baseUrl, url));
return '';
});
return new StyleWithImports(modifiedCssText, foundUrls);
}
const CSS_IMPORT_REGEXP = /@import\s+(?:url\()?\s*(?:(?:['"]([^'"]*))|([^;\)\s]*))[^;]*;?/g;
const CSS_COMMENT_REGEXP = /\/\*.+?\*\//g;
const URL_WITH_SCHEMA_REGEXP = /^([^:/?#]+):/;