pdf.js/web/download_manager.js

/* Copyright 2013 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.
 */

import { createObjectURL, createValidAbsoluteUrl, PDFJS } from 'pdfjs-lib';

if (typeof PDFJSDev !== 'undefined' && !PDFJSDev.test('CHROME || GENERIC')) {
  throw new Error('Module "pdfjs-web/download_manager" shall not be used ' +
                  'outside CHROME and GENERIC builds.');
}

function download(blobUrl, filename) {
  let a = document.createElement('a');
  if (a.click) {
    // Use a.click() if available. Otherwise, Chrome might show
    // "Unsafe JavaScript attempt to initiate a navigation change
    //  for frame with URL" and not open the PDF at all.
    // Supported by (not mentioned = untested):
    // - Firefox 6 - 19 (4- does not support a.click, 5 ignores a.click)
    // - Chrome 19 - 26 (18- does not support a.click)
    // - Opera 9 - 12.15
    // - Internet Explorer 6 - 10
    // - Safari 6 (5.1- does not support a.click)
    a.href = blobUrl;
    a.target = '_parent';
    // Use a.download if available. This increases the likelihood that
    // the file is downloaded instead of opened by another PDF plugin.
    if ('download' in a) {
      a.download = filename;
    }
    // <a> must be in the document for IE and recent Firefox versions.
    // (otherwise .click() is ignored)
    (document.body || document.documentElement).appendChild(a);
    a.click();
    a.parentNode.removeChild(a);
  } else {
    if (window.top === window &&
        blobUrl.split('#')[0] === window.location.href.split('#')[0]) {
      // If _parent == self, then opening an identical URL with different
      // location hash will only cause a navigation, not a download.
      let padCharacter = blobUrl.indexOf('?') === -1 ? '?' : '&';
      blobUrl = blobUrl.replace(/#|$/, padCharacter + '$&');
    }
    window.open(blobUrl, '_parent');
  }
}

class DownloadManager {
  downloadUrl(url, filename) {
    if (!createValidAbsoluteUrl(url, 'http://example.com')) {
      return; // restricted/invalid URL
    }
    download(url + '#pdfjs.action=download', filename);
  }

  downloadData(data, filename, contentType) {
    if (navigator.msSaveBlob) { // IE10 and above
      return navigator.msSaveBlob(new Blob([data], { type: contentType, }),
                                  filename);
    }
    let blobUrl = createObjectURL(data, contentType,
                                  PDFJS.disableCreateObjectURL);
    download(blobUrl, filename);
  }

  download(blob, url, filename) {
    if (navigator.msSaveBlob) {
      // IE10 / IE11
      if (!navigator.msSaveBlob(blob, filename)) {
        this.downloadUrl(url, filename);
      }
      return;
    }

    if (PDFJS.disableCreateObjectURL) {
      // URL.createObjectURL is not supported
      this.downloadUrl(url, filename);
      return;
    }

    let blobUrl = URL.createObjectURL(blob);
    download(blobUrl, filename);
  }
}

export {
  DownloadManager,
};