Upload an Image and Display it back as a response using Flask

Richa Netto picture Richa Netto · Mar 16, 2017 · Viewed 9.1k times · Source

I'm a beginner in front end development, and have to do a small web app in Flask for a project.

I have written a Flask app that lets you upload an image using HTML Forms and then displays the image back to the user when you hit Upload. I need to modify this such that the image does not get saved to a folder in the project directory everytime a user uploads it. Basically, the app should send the uploaded image back in the body of the response.

Here is my code so far:

UploadTest.py

import os


from uuid import uuid4

from flask import Flask, request, render_template, send_from_directory

app = Flask(__name__)
# app = Flask(__name__, static_folder="images")



APP_ROOT = os.path.dirname(os.path.abspath(__file__))

@app.route("/")
def index():
    return render_template("upload.html")

@app.route("/upload", methods=["POST"])
def upload():
    target = os.path.join(APP_ROOT, 'images/')
    print(target)
    if not os.path.isdir(target):
            os.mkdir(target)
    else:
        print("Couldn't create upload directory: {}".format(target))
    print(request.files.getlist("file"))
    for upload in request.files.getlist("file"):
        print(upload)
        print("{} is the file name".format(upload.filename))
        filename = upload.filename
        destination = "/".join([target, filename])
        print ("Accept incoming file:", filename)
        print ("Save it to:", destination)
        upload.save(destination)

    return render_template("complete.html", image_name=filename)

@app.route('/upload/<filename>')
def send_image(filename):
    return send_from_directory("images", filename)

if __name__ == "__main__":
    app.run(port=8080, debug=True)

upload.html - creates an upload form

<!DOCTYPE html>
<html>
<head>
<title>Upload</title>
 <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
</head>
<body>

<form id="upload-form" action="{{ url_for('upload') }}" method="POST" enctype="multipart/form-data">

    <strong>Files:</strong><br>
    <input id="file-picker" type="file" name="file" accept="image/*" multiple>
    <div id="msg"></div>
    <input type="submit" value="Upload!" id="upload-button">
</form>
</body>
<script>

    $("#file-picker").change(function(){

        var input = document.getElementById('file-picker');

        for (var i=0; i<input.files.length; i++)
        {

            var ext= input.files[i].name.substring(input.files[i].name.lastIndexOf('.')+1).toLowerCase()

            if ((ext == 'jpg') || (ext == 'png'))
            {
                $("#msg").text("Files are supported")
            }
            else
            {
                $("#msg").text("Files are NOT supported")
                document.getElementById("file-picker").value ="";
            }

        }


    } );

</script>
</html>

complete.html - displays the image from the folder in which it has been saved after a user hits "upload"

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
Uploaded
<img src=" {{url_for('send_image', filename=image_name)}}">
</body>
</html>

I have tried researching quite a bit but was unable to find anything other than deleting the folder after it has been displayed (which I didn't think is the right way of solving the question at hand). I'd really appreciate any help in this matter, and if there is a better solution than what my code currently does, I'd love to learn more!

Thank you! :)

Answer

Shubham S. Naik picture Shubham S. Naik · Oct 12, 2019

Please check below code can help you.Copy the below code in upload.html in templates folder.

<!DOCTYPE html>

<html>
<head>
<link class="jsbin" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1/themes/base/jquery-ui.css" rel="stylesheet" type="text/css" />
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.0/jquery-ui.min.js"></script>
<meta charset=utf-8 />

 <script src="{{ url_for('static', filename='upload.js') }}"></script>

<style>
  article, aside, figure, footer, header, hgroup, 
  menu, nav, section { display: block; }
</style>
</head>
<body>
<form action = "http://127.0.0.1:5000/uploader" method = "POST" 
 enctype = "multipart/form-data">
  <input type='file' name = 'file' onchange="readURL(this);" />
    <img id="blah" src="#" alt="your image" />
 <input type = "submit"/>
</form>
</body>
</html>

Copy the below code in upload.js file in static folder

function readURL(input) {
if (input.files && input.files[0]) {
    var reader = new FileReader();

    reader.onload = function (e) {
        $('#blah')
            .attr('src', e.target.result)
            .width(150)
            .height(200);
    };

    reader.readAsDataURL(input.files[0]);
}
}

Now copy the below code in a python file

from flask import Flask, render_template, request
from werkzeug import secure_filename
import os 

app = Flask(__name__)

app.config['UPLOAD_FOLDER'] = 'D:/Projects/flask/image_upload/images/'

@app.route('/')
def upload_f():
   return render_template('upload.html')

@app.route('/uploader', methods = ['GET', 'POST'])
def upload_file():
   if request.method == 'POST':
      f = request.files['file']
      f.save(os.path.join(app.config['UPLOAD_FOLDER'],secure_filename(f.filename)))
      return 'file uploaded successfully'

# if __name__ == '__main__':
app.run(debug = True)

Above piece of code will help you to browse and display the image on html page and as well save the image on your disk at desired location.