CODEWITHSUNDEEP
python-3.xflask
user1625066
user1625066

Reputation:

Flask - custom error messages on abort

I'd like to be able to display custom error messages using abort() in Flask. I have run into an unusual situation that I am having trouble with. My code is below.

from flask import Flask, abort, jsonify, make_response, request

app = Flask(__name__)

@app.errorhandler(400)
def custom400(error):
    return make_response(jsonify({'message': error.description}), 400)

@app.route('/test', methods=['POST'])
def test():
    abort(400, 'custom error message')

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

The code above works but behaves differently if I attempt to access any form data because I lose access to the custom error message.

def test():
    a = request.form['some_value']
    abort(400, 'custom error message')

How can I avoid this situation? Is this a Flask bug?

Note: The code above was taken from how to get access to error message from abort command when using custom error handler

Upvotes: 5

Views: 11032

Answers (2)

Patrick Mutuku
Patrick Mutuku

Reputation: 1175

If you want to be able to render a template together with the error message, you can define the error handler

@app.errorhandler(404)
def page_not_found(error):
    error=['Page Not Found','Oops']
    return render_template('errors.html', error=error), 404

To use, raise the error by

abort(404)

Make sure to import abort 

from flask import abort

Then you can access the error message list in jinja

Upvotes: 1

Sean Vieira
Sean Vieira

Reputation: 159905

The error doesn't have a description because you aren't setting some_value in your POST body so the 400 error comes from request.form.__getitem__ - change the first line of test to a = request.form.get('some_value') and your abort error will be thrown instead.

Upvotes: 4

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