flask: error_handler for blueprints

Question

Can error_handler be set for a blueprint?

@blueprint.errorhandler(404) def page_not_found(error):     return 'This page does not exist', 404 

edit:

https://github.com/mitsuhiko/flask/blob/18413ed1bf08261acf6d40f8ba65a98ae586bb29/flask/blueprints.py

you can specify an app wide and a blueprint local error_handler

Answer 1

You can use Blueprint.app_errorhandler method like this:

bp = Blueprint('errors', __name__)  @bp.app_errorhandler(404) def handle_404(err):     return render_template('404.html'), 404  @bp.app_errorhandler(500) def handle_500(err):     return render_template('500.html'), 500 

Answer 2

errorhandler is a method inherited from Flask, not Blueprint. If you are using Blueprint, the equivalent is app_errorhandler.

The documentation suggests the following approach:

def app_errorhandler(self, code):         """Like :meth:`Flask.errorhandler` but for a blueprint.  This         handler is used for all requests, even if outside of the blueprint.         """ 

Therefore, this should work:

from flask import Blueprint, render_template  USER = Blueprint('user', __name__)  @USER.app_errorhandler(404) def page_not_found(e):     """ Return error 404 """     return render_template('404.html'), 404 

On the other hand, while the approach below did not raise any error for me, it didn't work:

from flask import Blueprint, render_template  USER = Blueprint('user', __name__)  @USER.errorhandler(404) def page_not_found(e):     """ Return error 404 """     return render_template('404.html'), 404