I am fetching data from an API in order to show sales and finance reports, but I receive a type gzip file which I managed to convert into a Uint8Array. I'd like to somehow parse-decode this into a JSON file that I can use to access data and create charts in my frontend with.
I was trying with different libraries (pako and cborg seemed to be the ones with the closest use cases), but I ultimately get an error Error: CBOR decode error: unexpected character at position 0
This is the code as I have it so far:
let req = https.request(options, function (res) {
console.log("Header: " + JSON.stringify(res.headers));
res.setEncoding("utf8");
res.on("data", function (body) {
const deflatedBody = pako.deflate(body);
console.log("DEFLATED DATA -----> ", typeof deflatedBody, deflatedBody);
console.log(decode(deflatedBody));
});
res.on("error", function (error) {
console.log("connection could not be made " + error.message);
});
});
req.end();
};
I hope anyone has stumbled upon this already and has some idea. Thanks a lot!
I am fetching data from an API in order to show sales and finance reports, but I receive a type gzip file which I managed to convert into a Uint8Array. I'd like to somehow parse-decode this into a JSON file that I can use to access data and create charts in my frontend with.
I was trying with different libraries (pako and cborg seemed to be the ones with the closest use cases), but I ultimately get an error Error: CBOR decode error: unexpected character at position 0
This is the code as I have it so far:
let req = https.request(options, function (res) {
console.log("Header: " + JSON.stringify(res.headers));
res.setEncoding("utf8");
res.on("data", function (body) {
const deflatedBody = pako.deflate(body);
console.log("DEFLATED DATA -----> ", typeof deflatedBody, deflatedBody);
console.log(decode(deflatedBody));
});
res.on("error", function (error) {
console.log("connection could not be made " + error.message);
});
});
req.end();
};
I hope anyone has stumbled upon this already and has some idea. Thanks a lot!
Share Improve this question edited Jul 20, 2021 at 10:26 evolutionxbox 4,1226 gold badges38 silver badges57 bronze badges asked Jul 20, 2021 at 10:05 JacopoJacopo 1631 gold badge2 silver badges10 bronze badges 1- JSON has a strict set of allowed characters/content. json.org/json-en.html please may you make sure that you're converting it correctly? – evolutionxbox Commented Jul 20, 2021 at 10:33
2 Answers
Reset to default 14Please visit this answer https://stackoverflow.com/a/12776856/16315663 to retrieve GZIP data from the response.
Assuming, You have already retrieved full data as UInt8Array.
You just need the UInt8Array as String
const jsonString = Buffer.from(dataAsU8Array).toString('utf8')
const parsedData = JSON.parse(jsonString)
console.log(parsedData)
Edit
Here is what worked for me
const {request} = require("https")
const zlib = require("zlib")
const parseGzip = (gzipBuffer) => new Promise((resolve, reject) =>{
zlib.gunzip(gzipBuffer, (err, buffer) => {
if (err) {
reject(err)
return
}
resolve(buffer)
})
})
const fetchJson = (url) => new Promise((resolve, reject) => {
const r = request(url)
r.on("response", (response) => {
if (response.statusCode !== 200) {
reject(new Error(`${response.statusCode} ${response.statusMessage}`))
return
}
const responseBufferChunks = []
response.on("data", (data) => {
console.log(data.length);
responseBufferChunks.push(data)
})
response.on("end", async () => {
const responseBuffer = Buffer.concat(responseBufferChunks)
const unzippedBuffer = await parseGzip(responseBuffer)
resolve(JSON.parse(unzippedBuffer.toString()))
})
})
r.end()
})
fetchJson("https://wiki.mozilla.org/images/f/ff/Example.json.gz")
.then((result) => {
console.log(result)
})
.catch((e) => {
console.log(e)
})
Thank you, I actually just tried this approach and I get the following error:
SyntaxError: JSON Parse error: Unexpected identifier "x"
But I managed to print the data in text format using the below function:
getFinancialReports = (options, callback) => {
// buffer to store the streamed decompression
var buffer = [];
https
.get(options, function (res) {
// pipe the response into the gunzip to decompress
var gunzip = zlib.createGunzip();
res.pipe(gunzip);
gunzip
.on("data", function (data) {
// decompression chunk ready, add it to the buffer
buffer.push(data.toString());
})
.on("end", function () {
// response and decompression complete, join the buffer and return
callback(null, buffer.join(""));
})
.on("error", function (e) {
callback(e);
});
})
.on("error", function (e) {
callback(e);
});
};
Now I would need to pass this into a JSON object.