pdf.js/src/shared/streams_polyfill.js
Jonas Jenwald a9ce4e8417 Stop exposing the URL polyfill in the global scope
This moves/exposes the `URL` polyfill similarily to the existing `ReadableStream` polyfill, rather than exposing it globally, to avoid interfering with any "outside" code.
Both the `URL` and `ReadableStream` polyfills are now exposed on the `pdfjsLib` object, such that they are accessible to the viewer components.
Furthermore, the `no-restricted-globals` ESLint rule is also enabled to prevent accidental usage of the native `URL`/`ReadableStream` implementations directly in the `src/` and `web/` folders; see also https://eslint.org/docs/rules/no-restricted-globals

Addresses the remaining TODO in https://github.com/mozilla/pdf.js/projects/6
2018-07-04 09:16:28 +02:00

49 lines
1.6 KiB
JavaScript

/* Copyright 2017 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* eslint-disable no-restricted-globals */
let isReadableStreamSupported = false;
if (typeof ReadableStream !== 'undefined') {
// MS Edge may say it has ReadableStream but they are not up to spec yet.
try {
// eslint-disable-next-line no-new
new ReadableStream({
start(controller) {
controller.close();
},
});
isReadableStreamSupported = true;
} catch (e) {
// The ReadableStream constructor cannot be used.
}
}
if (isReadableStreamSupported) {
exports.ReadableStream = ReadableStream;
} else {
if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('IMAGE_DECODERS')) {
class DummyReadableStream {
constructor() {
throw new Error('The current image decoders are synchronous, ' +
'hence `ReadableStream` shouldn\'t need to be ' +
'polyfilled for the IMAGE_DECODERS build target.');
}
}
exports.ReadableStream = DummyReadableStream;
} else {
exports.ReadableStream =
require('../../external/streams/streams-lib').ReadableStream;
}
}