I make an API request which returns a binary image. How can I save it to a file like photo.png on my machine? Doing some research, I've tried the following but when I open the image, my machine says it's damaged:
const buffer = new Buffer(imageBinary);
const b64 = buffer.toString("base64");
const path = `temp/${userId}`;
const url = path + "/photo.png";
if (!fs.existsSync(path)) fs.mkdirSync(path);
if (fs.existsSync(url)) fs.unlinkSync(url)
fs.createWriteStream(url).write(b64);
return url;
Edit: Here is the binary data FYI: https://gist.github.com/AskYous/1fd26dc0eb02b4ec1672dcf5c61a34df
You do not need to re-encode the buffer as base64. Just write the binary buffer as is:
fs.createWriteStream(url).write(imageBinary);
Related
I am working in a project in which i need to create api using nodejs to upload video or image file to the postgres database
How i can do this
Thanks a lot
You can convert an image or video to base64, and then upload the base64 encoded string to your database.
const fs = require('fs');
function encode_base64(file) {
const bitmap = fs.readFileSync(file);
return new Buffer(bitmap).toString('base64');
}
const image = encode_base64('image.jpg');
const video = encode_base64('image.mp4');
I must read image file into memory on Firebase Cloud Function so I can convert to base64. But I get error:
Error: ENOENT: no such file or directory
// Read the file into memory.
const fs = require('fs');
const imageFile = fs.readFileSync('https://upload.wikimedia.org/wikipedia/commons/f/f7/Lower_Manhattan_skyline_-_June_2017.jpg');
// Convert the image data to a Buffer and base64 encode it.
const encoded = Buffer.from(imageFile).toString('base64');
How I can read remote image file into memory?
In my code, a function is returning a protobuf object and I want to save it in a file xyz.pb.
When I am trying to save it using fs.writefilesync it is not saving it.
It is circular in nature. So, I tried to save it using circular-json module to confirm if there is anything inside it and it has data.
But, as I used circular-json in the first place it doesn't have the proper information(not properly formatted) and it is of no use.
How can I save this protobuf in a file using nodejs?
Thanks!
you can try to use streams like mentioned in documentation
as following
const crypto = require('crypto');
const fs = require('fs');
const wstream = fs.createWriteStream('fileWithBufferInside');
// creates random Buffer of 100 bytes
const buffer = crypto.randomBytes(100);
wstream.write(buffer);
wstream.end();
or you can convert the buffer to JSON and save it in file as following:
const crypto = require('crypto');
const fs = require('fs');
const wstream = fs.createWriteStream('myBinaryFile');
// creates random Buffer of 100 bytes
const buffer = crypto.randomBytes(100);
wstream.write(JSON.stringify(buffer));
wstream.end();
and if your application logic doesn't require to use sync nature you should not use writeFileSync due to it will block your code until it will end so be careful.
try instead using writeFile or Streams it's more convenient.
The purpose of Protocol Buffers is to serialize strongly typed messages to binary format and back into messages. If you want to write a message from memory into a file, first serialize the message into binary and then write binary to a file.
NodeJS Buffer docs
NodeJS write binary buffer into a file
Protocol Buffers JavaScript SDK Docs
It should look something like this:
const buffer = messageInstance.serializeBinary()
fs.writeFile("filename.pb", buffer, "binary", callback)
I found how to easily save protobuf object in a file.
Convert the protobuf object into buffer and then save it.
const protobuf = somefunction(); // returning protobuf object
const buffer = protobuf.toBuffer();
fs.writeFileSync("filename.pb", buffer);
multiple zip File read and display in angularjs and those files convert base64 in nodejs and push into gitlab. please suggest me if it possible in nodejs. is there any blug available for reference.
use fs module of nodejs to read the files from directory
const testFolder = './tests/';
const fs = require('fs');
fs.readdirSync(testFolder).forEach(file => {
console.log(file);
});
once you get the files you can covert to base64
function base64_encode(file) {
// read binary data
var bitmap = fs.readFileSync(file);
// convert binary data to base64 encoded string
return new Buffer(bitmap).toString('base64');
}
I am making a Node.js/Electron application that downloads and displays images. I am downloading an image from the internet using request. I want to save this image in memory and display it without saving the file on the local hard drive. I am aware I could accomplish what I am asking here by inserting <img src="url"> into the DOM, but this is a heavily simplified version of my code and what I am trying to accomplish can not be done with that.
var image = fs.createWriteStream(?); // Is there anyway to save the image to memory?
request(url).pipe(image);
$('img').exampleScriptToSetImage(image); // And is there any way to display that image in a element without saving it to the local disk and loading its path?
Indeed! You can pipe your requested image data into a concat stream, convert the buffer to base64, and set the base64 encoding as your image source.
var path = require('path')
var request = require('request') // or hyperquest, simple-get, etc...
var concat = require('concat-stream')
var image = request(url)
image.pipe(concat({ encoding: 'buffer' }, function (buf) {
var ext = path.extname(file.name).slice(1) // assuming you have the file name
if (ext === 'svg') ext = 'svg+xml'
var src = 'data:image/' + ext + ';base64,' + buf.toString('base64')
var img = document.createElement('img')
img.src = src
document.body.appendChild(img)
})