@oat-sa/tao-core-sdk/src/util/download.js

Core libraries of TAO

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2019 (original work) Open Assessment Technologies SA;
 *
 */
/**
 *
 * @author Martin Nicholson <martin@taotesting.com>
 */
import _ from 'lodash';

/**
 * Check for iOS platform
 * @type {Boolean}
 */
const iOS = !!navigator.platform && /iPad|iPhone|iPod/.test(navigator.platform);
/**
 * File type
 * @type {string}
 */
const type = iOS ? 'data:application/octet-stream' : 'data:text/plain';

/**
 * Make the browser start downloading a file
 * @param {String} filename
 * @param {String} content - String to write to the file
 * @throws {TypeError}
 * @returns {Boolean}
 */
function download(filename, content) {
    if (_.isEmpty(filename) || !_.isString(filename)) {
        throw new TypeError('Invalid filename');
    }

    if (_.isUndefined(content)) {
        throw new TypeError('Invalid content');
    }

    if (!_.isString(content)) {
        content = JSON.stringify(content);
    }

    if (navigator.msSaveBlob) {
        navigator.msSaveBlob(new Blob([content], { type: type }), filename);
        return true;
    }

    const element = document.createElement('a');
    iOS && element.setAttribute('target', '_blank');
    element.setAttribute('href', `${type};charset=utf-8,${encodeURIComponent(content)}`);
    element.setAttribute('download', filename);
    element.style.display = 'none';
    document.body.appendChild(element);
    element.click();
    document.body.removeChild(element);
    return true;
}

/**
 * @exports download
 */
export default download;