53 lines
1.8 KiB
JavaScript
53 lines
1.8 KiB
JavaScript
|
/**
|
||
|
* Returns a `Buffer` instance from the given data URI `uri`.
|
||
|
*
|
||
|
* @param {String} uri Data URI to turn into a Buffer instance
|
||
|
* @returns {Buffer} Buffer instance from Data URI
|
||
|
* @api public
|
||
|
*/
|
||
|
export function dataUriToBuffer(uri) {
|
||
|
if (!/^data:/i.test(uri)) {
|
||
|
throw new TypeError('`uri` does not appear to be a Data URI (must begin with "data:")');
|
||
|
}
|
||
|
// strip newlines
|
||
|
uri = uri.replace(/\r?\n/g, '');
|
||
|
// split the URI up into the "metadata" and the "data" portions
|
||
|
const firstComma = uri.indexOf(',');
|
||
|
if (firstComma === -1 || firstComma <= 4) {
|
||
|
throw new TypeError('malformed data: URI');
|
||
|
}
|
||
|
// remove the "data:" scheme and parse the metadata
|
||
|
const meta = uri.substring(5, firstComma).split(';');
|
||
|
let charset = '';
|
||
|
let base64 = false;
|
||
|
const type = meta[0] || 'text/plain';
|
||
|
let typeFull = type;
|
||
|
for (let i = 1; i < meta.length; i++) {
|
||
|
if (meta[i] === 'base64') {
|
||
|
base64 = true;
|
||
|
}
|
||
|
else {
|
||
|
typeFull += `;${meta[i]}`;
|
||
|
if (meta[i].indexOf('charset=') === 0) {
|
||
|
charset = meta[i].substring(8);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
// defaults to US-ASCII only if type is not provided
|
||
|
if (!meta[0] && !charset.length) {
|
||
|
typeFull += ';charset=US-ASCII';
|
||
|
charset = 'US-ASCII';
|
||
|
}
|
||
|
// get the encoded data portion and decode URI-encoded chars
|
||
|
const encoding = base64 ? 'base64' : 'ascii';
|
||
|
const data = unescape(uri.substring(firstComma + 1));
|
||
|
const buffer = Buffer.from(data, encoding);
|
||
|
// set `.type` and `.typeFull` properties to MIME type
|
||
|
buffer.type = type;
|
||
|
buffer.typeFull = typeFull;
|
||
|
// set the `.charset` property
|
||
|
buffer.charset = charset;
|
||
|
return buffer;
|
||
|
}
|
||
|
export default dataUriToBuffer;
|
||
|
//# sourceMappingURL=index.js.map
|