Overwrite Route in Flask Blueprint
There Is a Blueprint with a Lot of Useful Routes Defined, but I Have No Control over It (Can Not Change It's Code in Any Way) Trying to Reuse It in a Different...
There is a blueprint with a lot of useful routes defined, but I have no control over it (can not change it's code in any way) Trying to reuse it in a different app but one of the blueprint's endpoints must be overloaded. How can I achieve that?
I tried just adding a new route to blueprint on top of the existing one:
@blueprint.route('/my/route', methods=['PUT', 'POST'])
def my_new_view_func(program, project):
# some new behavior for the endpoint
As the result there is duplicate url_rule in app.url_map.iter_rules():
<Rule '/my/route' (PUT, POST) -> my_view_func>,
<Rule '/my/route' (PUT, POST) -> my_new_view_func>,
and when requesting /my/route old viewer my_view_func gets executed
Can I somehow get rid of the old url rule? Or maybe there is a better way to overwrite the route?
1 Answer
There are 2 solutions which I found. First:
from flask import Flask, Blueprint
simple_page = Blueprint('simple_page', __name__, )
@simple_page.route('/my/route/')
def my():
# for example it's a registered route somewhere...
return 'default'
@simple_page.route('/my/route/')
def new_my():
# new endpoint / should works instead my()
return 'new'
# map of views which we won't register in Flask app
# you can store this somewhere in settings
SKIP_VIEWS = (
# route, view function
('/my/route/', my, ),
)
class CustomFlask(Flask):
def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
# Flask registers views when an application starts
# do not add view from SKIP_VIEWS
for rule_, view_func_ in SKIP_VIEWS: # type: str, func
if rule_ == rule and view_func == view_func_:
return
return super(CustomFlask, self).add_url_rule(rule, endpoint, view_func, **options)
app = CustomFlask(__name__)
app.register_blueprint(simple_page)
app.run(debug=True)
Second way:
two.py - default blueprint with endpoint
from flask import Blueprint
bp_two = Blueprint('simple_page2', __name__, )
@bp_two.route('/my/route/')
def default():
return 'default'
test.py - your blueprint + app
from flask import Flask, Blueprint
from two import bp_two
your_bp = Blueprint('simple_page', __name__, )
@your_bp.route('/my/route/')
def new_route():
return 'new'
app = Flask(__name__)
# register blueprint and turn off '/my/route/' endpoint
app.register_blueprint(bp_two, **{'url_defaults': {'/my/route/': None}})
app.register_blueprint(your_bp)
app.run(debug=True)
Run app. Open /my/route/. You will see that default endpoint wasn't add/works.
Hope this helps.
James Sterling reports on renewable energy developments, climate policy, ecological conservation, and green tech innovations around the globe.
