How to get gif from get response - Javascript

Patcmpro
March 28, 2023
149 views
0 votes
2 Answers

Here i have my flask function that returns the image:

@app.route("/getResults", methods=['GET'])
def get_results():
    print(request)
    job_key = request.args["id"]
    filename = '/home/pat/projets/giftmaker/webapp/public/workingDir/1/test.png'
    return send_file(filename, mimetype='image/png')

then I have my attemp to read it:

export function Download ({jobID}) {
    
    const [img, setImg] = useState(null);
    
    
    function test() {
        const params = new URLSearchParams([['id', jobID]]);
        axios.get('/getResults', {params}, {responseType: "arraybuffer"})
            .then((response) => {
                setImg(Buffer.from(response.data, "binary").toString("base64"))
            })
            .catch((e) => {
                console.log(e)
            })
     };



    return(
     <div>
        <button onClick={test}> Display </button>
        <img src={`data:image/png;base64,${img}`} />
     </div>
    )
};

this is the response i get from the get request :

�PNG

�
���
IHDR���h���h�����������=�zTXtRaw profile type exif��xڥ�Y��6�m��Vd�H

its actually longer than that but you get the idea…

I have tried so many thing that i found from stackoverflow but nothing seems to work.
I am testing out with a small image but it should be a gif that can be 1-5Mb

The data send from flask.send_file is binary right ?

Answers

Chosen as BEST ANSWER

I am lucky enough to control the back-end so i modified it a little bit

with open(filepath, "rb") as f:
        encodedZip = base64.b64encode(f.read())
    
    return encodedZip.decode()

frontend:

function getResults() {       
        //console.log("ok")
        const params = new URLSearchParams([['id', jobID]]);
        axios.get('/getResults', {params}, {responseType: "arraybuffer"})
            .then((response) => {
              setImg(response.data)
            })
            .catch((e) => {
                console.log(e)
            })
     };


return(
        <div>
            <img src={`data:image/png;charset=utf-8;base64,${img}`} />
        </div>
        
    )
};

(Edit)

Yes, the data returned from send_file is binary. There are multiple reasons why this could go wrong:

CORS: Maybe the connection from your frontend was refused, check in the dev tools, if the request was successfull, you should see the image in "Preview"
Missing dependecies: You use "Buffer" which is a package you need to import. If that should be the problem, you’d get a error in the console saying that "Buffer is not defined"
Also be sure to check that the image you’re returning actually exists 🙂

I got it working like this:

api.py

from flask import Flask, request, send_file
from flask_cors import CORS

app = Flask(__name__)
CORS(app)

@app.route("/", methods=['GET'])
def get_results():
    print(request)
    filename = 'test.png'
    return send_file(filename, mimetype='image/png')

app.run(host='0.0.0.0', port=8081)

App.js

import React, { useState } from 'react';
import axios from 'axios';
import { Buffer } from 'buffer';

function App() {
  const [img, setImg] = useState(null);

  function test() {
    axios.get('http://localhost:8081', { responseType: "arraybuffer" })
      .then((response) => {
        setImg(Buffer.from(response.data, "binary").toString("base64"))
      })
      .catch((e) => {
        console.log(e)
      })
  };


  return (
    <div>
      <button onClick={test}> Display </button>
      <img src={`data:image/png;base64,${img}`} />
    </div>
  )
}

export default App;

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How to get gif from get response – Javascript

Answers