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Last active December 14, 2015 18:39
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Enhance Flask url_for() with optional _strict argument
import re
from flask import url_for
from myflaskapp import app
def url_for_ex(endpoint, **values):
"""Improved version of standard Flask's :func:`url_for`
that accepts an additional, optional ``_strict`` argument.
:param _strict: If ``False``, values for the endpoint are not checked
for compatibility with types defined in the URL rule.
Default: ``True``.
strict = values.pop('_strict', True)
if not strict:
# search for matching URL rule; if that fails, we will just
# invoke url_for() normally so that Flask can handle the error
url_arguments = set(key for key in values.iterkeys()
if not key.startswith('_'))
url_rule = None
for rule in app.url_map.iter_rules(endpoint):
rule_arguments = set(rule._converters.iterkeys())
if rule_arguments == url_arguments:
url_rule = rule.rule
if url_rule:
# replace argument placeholders in the URL rule (``<int:foo>``...)
# with values provided for those arguments
regex = '|'.join(r'\<(?:\w+\:)?(%s)\>' % arg for arg in values)
return re.sub(regex, lambda m: str(values[]), url_rule)
return url_for(endpoint, **values)
app.jinja_env.globals['url_for'] = url_for_ex
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