Flash messaging not working in Flask

Question

I have been unable to get the flash function to work in flask. Heres my code.

#!venv/bin/python3
from flask import Flask, flash

app = Flask(__name__)
app.config['SECRET_KEY'] = '12345'

@app.route('/')
def index():
    flash('Hi')
    return 'Hello'

if __name__ == '__main__':
    app.run()

I expected this to flash a message saying hi but when I load the page no flash box appears. What am I not understanding here?

Answer 1

I think the main problem is that you're returning a string and not a render_template that handles the flash and converts it to a display message. Check out this documentation code here for an example of how to handle flashes

So I suggest trying: return render_template('index.html')

And then use the index.html file to set up your code that handles the flash message. I have a feeling that just returning a string, as you've done here, without somewhere for the code to understand the flash will give a null result.