| 'use strict'; |
| |
| /** |
| * Module exports. |
| */ |
| |
| module.exports = dataUriToBuffer; |
| |
| /** |
| * Returns a `Buffer` instance from the given data URI `uri`. |
| * |
| * @param {String} uri Data URI to turn into a Buffer instance |
| * @return {Buffer} Buffer instance from Data URI |
| * @api public |
| */ |
| |
| 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 |
| var firstComma = uri.indexOf(','); |
| if (-1 === firstComma || firstComma <= 4) throw new TypeError('malformed data: URI'); |
| |
| // remove the "data:" scheme and parse the metadata |
| var meta = uri.substring(5, firstComma).split(';'); |
| |
| var base64 = false; |
| var charset = 'US-ASCII'; |
| for (var i = 0; i < meta.length; i++) { |
| if ('base64' == meta[i]) { |
| base64 = true; |
| } else if (0 == meta[i].indexOf('charset=')) { |
| charset = meta[i].substring(8); |
| } |
| } |
| |
| // get the encoded data portion and decode URI-encoded chars |
| var data = unescape(uri.substring(firstComma + 1)); |
| |
| var encoding = base64 ? 'base64' : 'ascii'; |
| var buffer = new Buffer(data, encoding); |
| |
| // set `.type` property to MIME type |
| buffer.type = meta[0] || 'text/plain'; |
| |
| // set the `.charset` property |
| buffer.charset = charset; |
| |
| return buffer; |
| } |