flask和url_for（）和werkzeug.routing.BuildError

Question

This is a pretty simple blueprint/controller:

maintenance_controller = Blueprint('maintenance', __name__, url_prefix='/maintenance')

@maintenance_controller.route('/csv', methods=['GET','POST'])
def csv():
    return render_template('/maintenance/csv.html')

Then, in csv.html :

<form action="{{ url_for('csv') }}">
...
</form>

However, this yields an exception:

werkzeug.routing.BuildError
BuildError: ('/csv', {}, None)

What am I missing?

Answer 1

You'll need to give a blueprint-relative path:

<form action="{{ url_for('.csv') }}">

provided the template is in the same blueprint. For templates outside of the blueprint you need to include the blueprint name:

<form action="{{ url_for('maintenance.csv') }}">

See the Building URLs section of the Blueprints documentation.