file-open.mjs

/**
 * Copyright 2020 Google LLC
 *
 * 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.
 */
// @license © 2020 Google LLC. Licensed under the Apache License, Version 2.0.

/**
 * @type { typeof import("../../index").fileOpen }
 */
export default async (options = {}) => {
  return new Promise((resolve, reject) => {
    const input = document.createElement('input');
    input.type = 'file';
    const accept = [
      ...(options.mimeTypes ? options.mimeTypes : []),
      options.extensions ? options.extensions : [],
    ].join();
    input.multiple = options.multiple || false;
    input.accept = accept || '*/*';

    const cancelDetector = () => {
      window.removeEventListener('focus', cancelDetector);
      if (input.files.length === 0) {
        reject(new DOMException('The user aborted a request.', 'AbortError'));
      }
    };

    input.addEventListener('click', () => {
      window.addEventListener('focus', cancelDetector, true);
    });

    input.addEventListener('change', () => {
      resolve(input.multiple ? input.files : input.files[0]);
    });

    input.click();
  });
};