id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
19100	@cache_page argument parsing is misleading	ksamuel	nobody	"Yesterday we moved:

{{{#!python
@cache_page(max_age=60*30)
}}}

Which was working fine. To:

{{{#!python
@cache_page(max_age=60*30, cache=""alternative_cache"")
}}}

Which triggered the following error:

{{{
The only keyword arguments are cache and key_prefix
}}}

Which is not true since {{{@cache_page(max_age=60*30)}}} worked fine before.

Of course, after fiddling a bit, we realized that:

{{{#!python
@cache_page(60*30, cache=""alternative_cache"")
}}}

Worked. And we were a bit confused.

The source code of cache_page shows this:

{{{#!python
def cache_page(*args, **kwargs):
    ...
    cache_alias = kwargs.pop('cache', None)
    key_prefix = kwargs.pop('key_prefix', None)
    assert not kwargs, ""The only keyword arguments are cache and key_prefix""
}}}

I understand this is for legacy reasons, as I can see the deprecation warning below these lines:

{{{#!python
    def warn():
        import warnings
        warnings.warn('The cache_page decorator must be called like: '
                      'cache_page(timeout, [cache=cache name], [key_prefix=key prefix]). '
                      'All other ways are deprecated.',
                      PendingDeprecationWarning,
                      stacklevel=3)
}}}

 But then it should accept max_age as a keyword argument and raise the deprecation warning OR not accept it at all and have an explicit mandatory first positional argument being max_age. But not one behavior in one case, and another in the other case. "	Bug	closed	Core (Cache system)	1.4	Normal	invalid	cache, arguments		Unreviewed	0	0	0	0	1	0