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