GT2/GT2-iOS/node_modules/data-uri-to-buffer/index.js

56 lines
1.4 KiB
JavaScript

'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;
}