setDataURLPrefix.js

/**
 * 设置 DataURL 前缀、MIME 类型、base64 标识。
 *
 * 如果你需要获取DataURL 的 MIME 类型和数据本身，推荐使用 <a href="https://www.npmjs.com/package/data-urls">data-urls</a>。
 *
 * @alias module:Processor.setDataURLPrefix
 * @since 4.1.0
 * @see {@link https://developer.mozilla.org/zh-CN/docs/Web/URI/Schemes/data Data URLs}
 * @see {@link https://www.iana.org/assignments/media-types/media-types.xhtml Media Types}
 * @param {string} data 数据本身
 * @param {string} [mimeType="image/png"] MIME 类型，默认`image/png`
 * @param {boolean} [base64=true] 添加 base64 标识，默认`true`
 * @returns {string} DataURL 格式的字符串
 * @example
 *
 * const data = 'PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=';
 * setDataURLPrefix(data); // data:image/png;base64,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 * setDataURLPrefix(data, 'image/png', false); // data:image/png,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 * setDataURLPrefix(data, 'image/jpg'); // data:image/jpg;base64,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 * setDataURLPrefix(data, 'text/html'); // data:text/html;base64,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 * setDataURLPrefix(data, ''); // data:;base64,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 * setDataURLPrefix(data, '', false); // data:,PGEgaWQ9ImEiPjxiIGlkPSJiIj5oZXkhPC9iPjwvYT4=
 *
 */
function setDataURLPrefix(data, mimeType = 'image/png', base64 = true) {
    return `data:${mimeType}${base64 ? ';base64' : ''},${data}`;
}
export default setDataURLPrefix;