toImage and reading the base64 in node.js

plotly.js
1

I’m trying to save my image I created using Plotly.js on the client-side to a folder location on my server. I’m using toImage to convert the data to a base64 url, but I can’t seem to get the file to read into a viewable picture afterward. Help?

Client-side code:

//get the div and create the base64 url

graphdiv = document.getElementById(‘graphdivID’)
try{
var url = await Plotly.toImage(graphdiv, {format:‘jpeg’, height: 500, width: 500 })
} catch (err) {
console.log(err)
}

//set options to post it to the server

const options = {
method: ‘POST’,
headers: {
‘Content-type’: ‘application/json’
},
body: JSON.stringify(url)
};

//post the request to the server

const response = await fetch(’/saveimage’, options);

Server side:

router.post("/saveimage", (req, res) => {
const fs = require(‘fs’)
fs.writeFile(“testing.jpeg”, Buffer.from(req.body.url, “base64”), function(err) {});
});

Using this, the file is written, but when I go to open it, it’s unreadable - blank. Am I going about this the wrong way? Is there an easier way to recreate and save the image using the plotly package in node? Any help would be greatly appreciated

2

Do you get any error if you add a log in function(err) {}?

3

I don’t know. I ended up passing the plot variables (data,layout,config) via JSON, and then used the Node.js docs to stream the file.

4

Continuously similar concerns, I have you discovered an answer I took a stab at everything it actually doesn’t work.

5

If any suggestion please reply.

6

Did you ever find a solution for this? I’m in the same situation.