The wrapper that you typically see is the new function that is returned.
This usually invokes the original, given function in addition to some extra
("decorating") logic around that call. Based on that question it sounds like
you might want to check out some introductory material on decorators [1][2].
Django view decorators simply need to be able to decorate a view function or
class, which means they need to support decorating something that takes a
request and optional args and returns a response. That means your wrapper
function can specify this much of the signature, and that's how you get
ahold of the request to work with. So, based on your pseudocode:
def intercept_foos(view_func):
def wrapper(request, *args, **kwargs):
if request.user.foo():
return redirect('/foo')
return view_func(request, *args, **kwargs)
return wrapper
Then just apply it as you did in your urls.py example.
Hope this helps.
[1]
http://stackoverflow.com/questions/739654/understanding-python-decorators -
A good starting point
[2] http://micheles.googlecode.com/hg/decorator/documentation.html - A handy
module and discussion of preserving function signatures
--
Steven
On Tue, Oct 11, 2011 at 4:59 PM, Kurtis Mullins <kurtis.mull...@gmail.com>wrote:
> Thanks Fred! I tried to look through your code and understand what's going
> on -- but I'm still at a loss. I'm guessing I need to look at the Django
> source to see what should be returned when you hit a URL and what is passed.
> The wrapper is confusing me and I've seen that in Django code as well. I'm
> going to go out on a limb and say it's probably not as easy as I hoped,
> haha.
>
>
> On Tue, Oct 11, 2011 at 4:42 PM, Sells, Fred <fred.se...@adventistcare.org
> > wrote:
>
>> I'm no expert but this is what I built to log all user actions -- warts
>> and all
>>
>> def decorate(func):
>> ##################print 'Decorating %s...' % func.__name__
>> def wrapped( *args, **kwargs):
>> request = args[0]
>> if len(args)>1: command=str(args[1])
>> else: command = ''
>> ipaddr = request.META['REMOTE_ADDR']
>> user = request.session.get('user', None)
>> if user: userid = user.userid
>> else: userid = '?'
>> qs = extract_querystring_from_request(request)
>> parameters = Parameters(**qs)
>> resid = parameters.pop('resid', '')
>> assessmentid = parameters.pop('id', 0)
>> facility = parameters.pop('facility','')
>> modified = func.__name__ in ("setvalues", "setraw", "create",
>> 'editcaas')
>> ### print func.__name__, 'zzzzzzzzzzzzzzzzzzzzz', modified, qs
>> modified = modified or (func.__name__=='command' and
>> command!='print')
>> fieldnames = parameters.values().keys()
>> for signature in SIGNATURE_FIELDS:
>> if signature in fieldnames: command='signit'
>> if (not facility) and resid:
>> facility = resid[:2]
>> option = str(parameters)[:110]
>> action = '%s:%s' % (func.__name__, command)
>> ### print "\n\n\n\ncalled wrapped function with ", (action,
>> option, str(parameters))
>> record = models.HipaaLog.objects.create(Version=K.VERSION,
>> userid=userid,
>> Action=action,
>> Options=option,
>> #StartTime =
>> datetime.datetime.now(),
>>
>> AssessmentId=assessmentid, ResidentId=resid,
>> Modified = modified,
>> IpAddress = ipaddr,
>> Facility=facility)
>> #print record.Modified, record.Action, 'record'
>> results = func( *args, **kwargs)
>> #record.StopTime = datetime.datetime.now()
>> #record.save()
>> return results
>> ############################print 'done'
>> return wrapped
>>
>> --------------------------------
>> @decorate
>> def command(request, *args, **kwargs):
>> ...
>>
>> -----Original Message-----
>> From: django-users@googlegroups.com
>> [mailto:django-users@googlegroups.com] On Behalf Of Kurtis
>> Sent: Tuesday, October 11, 2011 12:03 PM
>> To: Django users
>> Subject: Sample Custom Decorator
>>
>> Hey Guys,
>>
>> Would anyone be willing to show me an example of a very simple and
>> dumb decorator for views? I've been trying to read the existing
>> decorators and play with a couple of snippets but I'm having a lot of
>> trouble with two aspects -- grabbing the User Instance and Redirecting
>> somewhere besides Login (without making it look like a hack).
>>
>> Here's some ugly pseudo-code for what I'm trying to accomplish...
>>
>> # Custom Decorator
>> def my_decorator(function = None)
>>
>> # Grab Data
>> request = how_do_i_get_this?
>> user = request.user
>>
>> # Perform Logic, Redirect or Continue Normally
>> if user.foo():
>> redirect to '/foo' URL
>> else
>> display requested view?
>>
>>
>> # Decorated TemplateView
>> url(r'^$', my_decorator(TemplateView.as_view(template_name =
>> 'bar.html'))),
>>
>> Thanks!
>>
>> --
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>>
>>
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>>
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