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uptime-kuma/server/image-data-uri.js
2022-04-21 13:01:22 +01:00

80 lines
2.6 KiB
JavaScript

/*
From https://github.com/DiegoZoracKy/image-data-uri/blob/master/lib/image-data-uri.js
Modified with 0 dependencies
*/
let fs = require("fs");
const { log } = require("../src/util");
let ImageDataURI = (() => {
/**
* Decode the data:image/ URI
* @param {string} dataURI data:image/ URI to decode
* @returns {?Object} An object with properties "imageType" and "dataBase64".
* The former is the image type, e.g., "png", and the latter is a base64
* encoded string of the image's binary data. If it fails to parse, returns
* null instead of an object.
*/
function decode(dataURI) {
if (!/data:image\//.test(dataURI)) {
log.error("image-data-uri", "It seems that it is not an Image Data URI. Couldn't match \"data:image/\"");
return null;
}
let regExMatches = dataURI.match("data:(image/.*);base64,(.*)");
return {
imageType: regExMatches[1],
dataBase64: regExMatches[2],
dataBuffer: new Buffer(regExMatches[2], "base64")
};
}
/**
* Endcode an image into data:image/ URI
* @param {(Buffer|string)} data Data to encode
* @param {string} mediaType Media type of data
* @returns {(string|null)} A string representing the base64-encoded
* version of the given Buffer object or null if an error occurred.
*/
function encode(data, mediaType) {
if (!data || !mediaType) {
log.error("image-data-uri", "Missing some of the required params: data, mediaType");
return null;
}
mediaType = (/\//.test(mediaType)) ? mediaType : "image/" + mediaType;
let dataBase64 = (Buffer.isBuffer(data)) ? data.toString("base64") : new Buffer(data).toString("base64");
let dataImgBase64 = "data:" + mediaType + ";base64," + dataBase64;
return dataImgBase64;
}
/**
* Write data URI to file
* @param {string} dataURI data:image/ URI
* @param {string} [filePath] Path to write file to
* @returns {Promise<string>}
*/
function outputFile(dataURI, filePath) {
filePath = filePath || "./";
return new Promise((resolve, reject) => {
let imageDecoded = decode(dataURI);
fs.writeFile(filePath, imageDecoded.dataBuffer, err => {
if (err) {
return reject("ImageDataURI :: Error :: " + JSON.stringify(err, null, 4));
}
resolve(filePath);
});
});
}
return {
decode: decode,
encode: encode,
outputFile: outputFile,
};
})();
module.exports = ImageDataURI;