Flask not being able to read image uploaded from html - python

I am trying to make a simple html webpage where a user can upload an image. This image is passed on to a flask API through a form wherein the image is passed to an image classification model. However, I am not able to recieve the image in the Flask API after I upload the file. I get an error saying
werkzeug.exceptions.BadRequestKeyError: 400 Bad Request: The browser (or proxy) sent a request that this server could not understand. KeyError: 'uploaded_img'
Can anyone guide me where I am going wrong?
My html code:
<body class="center-screen">
<div id="content">
<form id="url-form" action="/classify_image" method="post" enctype="multipart/form-data">
<h1>Upload Image</h1>
<div class="formcontainer">
<hr/>
<div class="container">
<label for="img">Upload image:</label>
<input type="file" id="img" name="uploaded_img" accept="image/*">
</div>
<button type="submit">
<strong>Classify Image</strong>
</button>
</div>
</form>
</div>
</body>
My flask endpoint:
#app.route('/classify_image', methods=['POST'])
def classify_image():
if request.method == 'POST':
print("Running")
f = request.files['uploaded_img']
model.predict(f)

Related

Call python's object method from flask jinja2 html file

I am trying to create youtube video downloader application using pytube and flask. All is done, except that a want to call pytube's stream download method from within the html script tag. How can i do it.
Here's my flask code
from flask import Flask, render_template, request
from pytube import YouTube
app = Flask(__name__)
#app.route("/")
def index():
return render_template("index.html", data=None)
#app.route("/download", methods=["POST", "GET"])
def downloadVideo():
if request.method == "POST":
url = request.form["videourl"]
if url:
yt = YouTube(url)
title = yt.title
thumbnail = yt.thumbnail_url
streams = yt.streams.filter(file_extension='mp4')
data = [title, thumbnail, streams, yt]
return render_template("index.html", data=data)
if __name__ == "__main__":
app.run(debug=True)
and here's my html code
<!DOCTYPE html>
<html>
<head>
<title> Youtube Downloader </title>
<meta name="viewport" content="width=device-width,initial-scale=1.0">
<link rel="stylesheet" href="static/css/style.css">
</head>
<body>
<div class="main">
<div class="header">
<div>
<img src="static/img/icon.png" width="48" height="48">
<h2> Youtube Downloader </h2>
</div>
<div>
<p> Convert and download youtube videos </p>
<p> in MP4 for free </p>
</div>
</div>
{% if not data %}
<div class="dform">
<form action="http://127.0.0.1:5000/download", method="POST">
<div class="inputfield">
<input type="input" name="videourl" placeholder="Search or Paste youtube link here" autocomplete="off">
<button type="submit"> Download </button>
</div>
</form>
</div>
{% else %}
<div class="videoinfo">
<img src="" class="thumbnail">
<h2> {{data[0]}} </h2>
</div>
<div class="quality">
<select id="streams">
{% for stream in data[2][:3] %}
<option value="{{stream.itag}}"> {{stream.resolution}} </option>
{% endfor %}
</select>
</div>
{% endif %}
</div>
<script type="text/javascript">
const image = document.querySelector(".thumbnail");
const select = document.querySelector("select");
let url = `{{data[1]}}`;
if (image) {
image.src = `${url}`;
window.addEventListener('change', function() {
var option = select.options[select.selectedIndex].value;
console.log(option);
{% set stream = data[3].get_by_itag(option) %}
{% stream.download() %}
});
}
</script>
</body>
</html>
I am trying to download the video using itag when a user clicks an option in the select element by using pytube get_by_itag() method.
From what I understand you want to do two things. You want to create a route on your flask app that will let serve up the youtube video based on an itag, and you want to be able to call that route from javascript.
This answer shows how to create a route to download the video.
To call a url that starts a file download from javascript you'll need to use the fetch method and open that link into an iFrame. This answer covers it.
Let me know if that covers your question.

How to automatically play an mp4 uploaded in flask app

I have a flask app with an upload button for videos (mp4), and I am trying to figure out how to get the video to play on the screen after upload. Currently, it opens a generic gray video screen, but no video plays. I am including portions of my app.py and index.html files below. I also have a predict button that I would like to be able to interact with while the video continues to play.
I would appreciate any suggestions for how to accomplish this.
#app.route('/', methods=['GET'])
def index():
# Main page
return render_template('index.html')
#app.route('/predict', methods=['GET', 'POST'])
def upload():
if request.method == 'GET':
return render_template('index.html')
if request.method == 'POST':
# Get the file from post request
f = request.files['file']
# Save the file to ./uploads
basepath = os.path.dirname(__file__)
file_path = os.path.join(
basepath, 'static', secure_filename(f.filename))
f.save(file_path)
result = model_predict(file_path, model)
return jsonify(result)
return None
if __name__ == '__main__':
# app.run(port=5002, debug=True)
# Serve the app with gevent
http_server = WSGIServer(('', 5000), app)
http_server.serve_forever()
`
<div>
<h4>
<center></center>
</h4>
<br>
</br>
<center>
<form id="upload-file" method="post" enctype="multipart/form-data">
<center>
<label for="imageUpload" class="upload-label">
Upload (mp4)
</label>
</center>
<input type="file" name="file" id="imageUpload" accept=".mp4">
</form>
</center>
<div class="image-section" style="display:none;">
<div class="img-preview">
<div id="imagePreview">
<html>
<head>
</head>
<center>
<body>
<center>
<video controls width="500" style="center">
<source src="{{url_for('static', filename=f)}}" type="video/mp4" autoplay>
Sorry, your browser doesn't support embedded videos.
</video>
</center>
</body>
</html>
<input type="file" name="file[]" class="file_multi_video" accept="video/*">
</div>
</div>
<div>
<button type="button" class="btn btn-primary btn-lg " id="btn-predict">Identify</button>
</div>
</div>
<div class="loader" style="display:none;"></div>
<h3 id="result">
<span> </span>
</h3>
</div>
</center>
You can use MJPEG to do this in HTML and you can see the answer at https://stackoverflow.com/a/61452182/10353754 to get some help.
You should just extract frmaes and send it to tag after encoding into JPEG format.

Python Flask render_template returns HTML script instead of redirecting to the HTML page

I have a Python script that uses Flask web framework to let users ask a question and depending on some certain questions, the application should ask back some questions to the user on a second webpage. The answers to the questions are evaluated based on the questions and displayed on the initial webpage.
model.py
### Importing Flask ###
from flask import Flask, render_template, request, session, redirect, url_for
### Initializing Flask ###
app = Flask(__name__)
#app.route('/')
def index():
return render_template('init.html')
#app.route('/handle_data', methods = ['POST', 'GET'])
def handle_data():
### User Inputs Question ###
userQuestion = request.form['userQuestion']
def model():
message = "Depends on User"
if message == "Depends on User":
return render_template('user_information.html', userQuestion = userQuestion)
else:
message = "Your answer is ABC."
return message
message = model()
return render_template('init.html', userQuestion = userQuestion, message = message)
#app.route('/user_information', methods = ['POST', 'GET'])
def user_information():
userLevel = request.form['userLevel']
userDOJ = request.form['userDOJ']
userType = request.form['userType']
message = "Answer for Eligibility."
return render_template('init.html', userLevel = userLevel, userDOJ = userDOJ, userType = userType, message = message)
if __name__ == '__main__':
app.run()
These are my two HTML files:
init.html (initial webpage)
<!DOCTYPE html>
<html>
<head>
<title>Human Resources</title>
<!-- for-mobile-apps -->
</head>
<body>
<div class="main">
<div class="w3_agile_main_grid">
<h2>Human Resource Portal</h2>
<br>
<p>Hi</p>
<form action="{{ url_for('handle_data') }}" method="post" class="agile_form">
<input type="text" name="userQuestion" placeholder="Ask your question..." required="">
<input type="submit" value="Submit">
</form>
<p>{{ message }}</p>
</div>
</div>
</body>
</html>
user_information.html (second webpage)
<!DOCTYPE html>
<html>
<head>
<title>Human Resources</title>
</head>
<body>
<div class="main">
<div class="w3_agile_main_grid">
<h2>Human Resource Portal</h2>
<form action="{{ url_for('user_information') }}" method="post" class="agile_form">
<!--<input type="text" name="userName" placeholder="Enter your name." required="">-->
<input type="text" name="userLevel" placeholder="What is your level?" required="">
<input type="text" name="userDOJ" placeholder="What is your date of joining?" required="">
<input type="text" name="userType" placeholder="Are you on sabbatical or specialist?" required="">
<input type="submit" value="Submit">
</form>
</div>
</div>
</body>
</html>
When I execute my script and enters a question, what I get is the HTML code for user_information.html as my answer which is not what I want.
Ouput after I click Submit:
https://ibb.co/cwhRpk
Expected output after I click Submit:
https://ibb.co/c7CFh5
https://ibb.co/dX9T25
I can get the desired output if I remove the model() construct but that will make my code inefficient because in my actual application I have to call model() multiple times with different parameters.
Can anyone please suggest me what approach should I take? I'm totally stuck in this part. Thanks, any help is appreciated!
Your nested model() function does not make any sense at all. It returns the result of render_template, which is a complete response including HTTP headers etc. If you try and insert that into another template, Jinja will be forced to try and convert it to a string, which gives the result you see.
This is not at all the way to compose templates. Jinja supports template inheritance; you should call render_template once only, using a child template that inherits from a common base.

Flask submit form and show inserted values

I am completely new to python and Flask and I am trying to run in my computer the code showed in this page:
http://runnable.com/UhLMQLffO1YSAADK/handle-a-post-request-in-flask-for-python
This are the steeps I follow and the code:
1-I have installed Flask
2-Files
File app.py
# We need to import request to access the details of the POST request
# and render_template, to render our templates (form and response)
# we'll use url_for to get some URLs for the app on the templates
from flask import Flask, render_template, request, url_for
# Initialize the Flask application
app = Flask(__name__)
# Define a route for the default URL, which loads the form
#app.route('/')
def form():
return render_template('form_submit.html')
# Define a route for the action of the form, for example '/hello/'
# We are also defining which type of requests this route is
# accepting: POST requests in this case
#app.route('/hello/', methods=['POST'])
def hello():
name=request.form['yourname']
email=request.form['youremail']
return render_template('form_action.html', name=name, email=email)
# Run the app :)
if __name__ == '__main__':
app.run(
host="0.0.0.0",
port=int("80")
)
File form_action.html
<html>
<head>
<title>Handle POST requests with Flask</title>
<link rel=stylesheet type=text/css href="style.css">
</head>
<body>
<div id="container">
<div class="title">
<h1>POST request with Flask</h1>
</div>
<div id="content">
Hello <strong>{{name}}</strong> ({{email}})!
</div>
</div>
</div>
</body>
</html>
File form_submit.html
<html>
<head>
<title>Handle POST requests with Flask</title>
<link rel=stylesheet type=text/css href="style.css">
</head>
<body>
<div id="container">
<div class="title">
<h1>POST request with Flask</h1>
</div>
<div id="content">
<form method="post" action="{{ url_for('hello') }}">
<label for="yourname">Please enter your name:</label>
<input type="text" name="yourname" /><br />
<label for="youremail">Please enter your email:</label>
<input type="text" name="youremail" /><br />
<input type="submit" value="Send" />
</form>
</div>
</div>
</div>
</body>
</html>
3-I run the py file:
sudo python app.py
[sudo] password for jose:
* Running on http://0.0.0.0:80/ (Press CTRL+C to quit)
When I open the browser I write:
file:///home/jose/Escritorio/python/app/form_submit.html
I insert the data in the 2 forms and I press Send and this is what happens:
URL: file:///home/jose/Escritorio/python/app/{{url_for('hello')}}
Web Page: File not found
What am I doing wrong?
0.0.0.0 means that you can access the flask website from outside of the website host. Use the host ip plus the port # you specified
http://:80/hello in your case. That should display the form_action.html you specified in your routes.
If you want save form data, your code didn't work. You must have a database or save in a file.

Send Post Request from other domain to GAE

I have write an simple python application on GAE.
class Upload(webapp2.RequestHandler):
def post(self):
self.response.out.write('HelloWorld')
app = webapp2.WSGIApplication(['/upload', Upload)],
debug=True)
And it can receive post request.
But there is something with it.
I write one test page.
<html>
<head></head>
<body>
<form action="http://localhost:8080/upload" method="POST">
<input type="text" name="content"/>
<input type="submit" value="submit local"/>
</form>
<form action="http://wp7-gps-tracker.appspot.com/upload" method="POST">
<input type="text" name="content"/>
<input type="submit" value="submit server"/>
</form>
</body>
</html>
The Result
Run in localhost:
Test with IE:Success!
Test with Chrome:Success!
Upload to GAE:
Test with IE:faild!
Test with Chrome:Success!
what's wrong with my application?
I find the problem!
The GAE was forbidden in china!
And my Chrome is using proxy so it can works!
In your face, Chinese government!
Try change action relative your environment ... GAE have different url for version of application.
action="/upload"
Try only using 1 form in your test page, maybe IE is having problem distinguishing which form to submit

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