That's awesome! Initially I was wanting to add them as class methods
since they only really would be useful with the Storage class, but
only decided not to because of the uniform access-by-key and access-by-
attribute functionality of the class. But now that I look at it more,
it seems like all web2py core modification occurs solely using the
item setters, so even ?x=1&getfirst=true will work with
request.vars.getfirst('getfirst'), for example.
Great idea, mr.freeze, thanks!
On Sep 19, 8:12 pm, "mr.freeze" <nat...@freezable.com> wrote:
> I made the proposed changes here:http://pastebin.com/kH2ZjtZH
>
> On Sep 19, 6:13 pm, mdipierro <mdipie...@cs.depaul.edu> wrote:
>
> > I do not like idea about adding them to the global namespace. I have
> > no objection to add them to the storage class.
>
> > On Sep 19, 5:31 pm, "mr.freeze" <nat...@freezable.com> wrote:
>
> > > I like the idea but disagree with adding these functions to the global
> > > namespace. What about adding them to the Storage class? Pseudocode:
>
> > > >>> request.vars.query = ['one','two']
> > > >>> q = request.vars.getfirst('query')
> > > >>> 'one'
>
> > > Same for getlast and getall. Thoughts?
>
> > > On Aug 21, 11:26 am, Kevin <extemporalgen...@gmail.com> wrote:
>
> > > > Yeah, use case might be as follows (let me know if there's already a
> > > > web2py pattern for this -- I just downloaded the framework a couple
> > > > days ago):
>
> > > > Perhaps a legacy RESTful API that is being porting to web2py -- it
> > > > uses HTTP conventions to query the server, and returns type-
> > > > appropriate content based on the request URL's file extension.
>
> > > > Thus the following would both work as expected when passed to the ,
>
> > > > /search?term=sir+robin&limit=3
> > > > /search.json?term=sir+robin&limit=3
>
> > > > def search():
> > > > # We're assuming it's a string -- but it could be a list
> > > > # point of failure.
> > > > if not re.match('\d+$', request.vars.limit):
> > > > raise HTTP(400, "limit must be an integer")
> > > > term = request.vars.term
> > > > for row in db(db.topics.term.contains(term)).select(db.topics.ALL,
> > > > limitby=(0, int(limit))):
> > > > pass
>
> > > > However, the following URL would likely raise a TypeError (if not in
> > > > web2py code, at least in commonly-seen naive code):
>
> > > > /search.json?term=sir+robin&term=brave&limit=3
>
> > > > The boilerplate way of fixing the function would be as follows:
>
> > > > def search():
> > > > limit = request.vars.limit
> > > > if not isinstance(limit, basestring):
> > > > limit = limit[0]
> > > > if not re.match('\d+$', limit):
> > > > raise HTTP(400, "limit must be an integer")
> > > > term = request.vars.term
> > > > if not isinstance(term, basestring):
> > > > term = term[0]
> > > > for row in db(db.topics.term.contains(term)).select(db.topics.ALL,
> > > > limitby=(0, int(limit))):
> > > > pass
>
> > > > The shorthand way of fixing it would be as follows -- note, it also
> > > > trivially extends it to allow multiple terms which are AND'd together
> > > > (in fewer lines than the boiler-plate example):
>
> > > > def search():
> > > > limit =getfirst(request.vars.limit)
> > > > if not re.match('\d+$', limit):
> > > > raise HTTP(400, "limit must be an integer")
> > > > query = db
> > > > for term in getall(request.vars.term):
> > > > query = query(db.topics.term.contains(term))
> > > > for row in query.select(db.topics.ALL, limitby=(0, int(limit))):
> > > > pass
>
> > > > Note that in these examples, I've modified thegetfirst, getlast, and
> > > > getallfunctionsso that they're specifically designed to work with
> > > > object attributes instead of dictionary keys, which allows for the
> > > > shorter syntax you see here (which is much more useful for working
> > > > with Storage objects, which as of 1.83.2 return None for non-existant
> > > > attributes). Although it's less flexible, the abbreviated syntax
> > > > makes them much more handy for working with request.vars,
> > > > request.get_vars, and request.post_vars (from which you only
> > > > reasonably expect either lists, or non-lists). So in essence, these
> > > > act as 'scalarify' and 'listify'functions.
>
> > > > Note that "getall(request.vars.non_existant)" will return [] instead
> > > > of [None] (so it's not a 'strict' listify function).
>
> > > > The revised (stillproposedpatch) is athttp://pastebin.com/8f9z4k6J.
> > > > Further examples of API use (in doctest format) are in thepatch.
> > > > Also, I discovered that the *old*patchwould have broken on strings
> > > > (so don't use thatpatch), which is what the code would've been
> > > > dealing about 100% of the time in real-world cases.
>
> > > > On Aug 21, 6:22 am, mdipierro <mdipie...@cs.depaul.edu> wrote:
>
> > > > > I never needed this but I have no opposition to include them.
> > > > > Could you provide a use case?
> > > > > What do other people think?
>
> > > > > On Aug 21, 12:27 am, Kevin <extemporalgen...@gmail.com> wrote:
>
> > > > > > Hi,
>
> > > > > > this is aproposedpatchtoaddglobalfunctionsfor accessing values
> > > > > > from (in particular) request.vars and friends (any dictionary-like
> > > > > > object will work) in a way that (safely) satisfies the assumption
> > > > > > that
> > > > > > the input vars for a given key are either singletons or lists.
>
> > > > > > Thefunctionsare rather simple:
>
> > > > > > Given the request: /a/b/c?x=abc
> > > > > >getfirst(request.vars, 'x') -> 'abc'
> > > > > > getlast(request.vars, 'x') -> 'abc'
> > > > > > getall(request.vars, 'x') -> ['abc']
>
> > > > > > Given the request: /a/b/c?x=abc&x=def
> > > > > >getfirst(request.vars, 'x') -> 'abc'
> > > > > > getlast(request.vars, 'x') -> 'def'
> > > > > > getall(request.vars, 'x') -> ['abc', 'def']
>
> > > > > > getall(request.vars, 'y') -> None
> > > > > > getall(request.vars, 'y') or [] -> []
>
> > > > > > If there is anything like this already, I certainly will retract my
> > > > > > suggestion. The potentially controversial parts are that the
> > > > > >functionsare defined in gluon.utils (I couldn't find a more logical
> > > > > > place to put them, and it makes no difference to me where they end
> > > > > > up), and they're loaded into the request environment, just like the
> > > > > > html helpers.
>
> > > > > >Patchcan be found at:http://pastebin.com/g6Vs9PrU
>
> > > > > > Background/motivation:
>
> > > > > > This function group is inspired by the behavior of <http://
> > > > > > pythonpaste.org/webob/reference.html#query-post-variables> and
> > > > > > similar
> > > > > > functionality that other frameworks provide, and would be
> > > > > > particularly
> > > > > > useful in cases where the client-side code is not managed by
> > > > > > something
> > > > > > like web2py's FORM interface -- as of version 1.83.2, web2py
> > > > > > prepares
> > > > > > a Storage instance such that:
>
> > > > > > /a/b/c?x=5 -> request.vars.x == '5'
> > > > > > /a/b/c?x=5&x=abc -> request.vars.x == ['5', 'abc']
>
> > > > > > This could lead to naive code like the following to fail with some
> > > > > > simple request fakery:
>
> > > > > > if request.vars.search.upper().startswith('FUZZY'): pass # some real
> > > > > > code here
>
> > > > > > It's possible that this kind of fakery could also lead to many of
> > > > > > the
> > > > > > web2py validators failing in common cases (though I haven't looked
> > > > > > into that much).
>
> > > > > > However, it is often allowable that the first (or last) value passed
> > > > > > is authoritative, leading to a more robust system.
>
>
