[Zope-dev] Re: Collector 697 should be critical!!!

[abel deuring]

Toby Dickenson wrote:
> 
> On Monday 02 December 2002 4:11 pm, Maik Jablonski wrote:
> 
> > I don't have much experience with the unicode-converters too... that's
> > my problem for this issue...:-(
> 
> I had seen this bug on the list, but hant spotted that it was a
> unicode-related. I will try to take a look sometime this week.
> 
> > Abel Deuring told me a patch, which solves the problem in the meanwhile:
> >
> > In OFS/dtml/properties.dtml I replaced
> >
> >   <select name="xyz:utf8:list" multiple>
> >
> > with:
> >
> >   <select name="xyz:utf8:list:string" multiple>
> >
> > It works for me, but I'm not sure, if this is a good approach on this
> > problem (think of the integers as items for the multiple-select).
> 
> I havent looked in detail yet, but my first impression is that this is a good
> approach.

Well, I think that this is just a workaround, but not a bugfix ;)

Assume that ulines property is used to define the set of possible values
for a multiple selection property. In this case one would expect to get
a ustring vaule back.

And as Maik already mentioned, it is even possible to use something like
[1, 2, 3,4] as the possible values of the multiple selection . OK, this
case does not work very well with older version of Zope too, but I think
that this shows the general problem: Currently (including older Zope
versions), there absolutely no type conversion for multiple selections.

My idea of a proper fix is to add a method to the PropertyManager which
returns the type of the first element of the list of the allowed values.
As a very trivial and not very elegant approach (sorry, I don't much
time at present;):

def type_as_string(self, selectValues):
    if type(selectValues[0]) == type(''):
        return 'string'
    elif type(selectValues[0]) == type(u''):
        return 'ustring'
    elif type(selectValues[0]) == type(0):
        return 'int'
    elif ....

With this method available, the multiple selection part of
OFS/dtml/properties.dtml could be changed from:

  <select name="<dtml-var id>:utf8:list" multiple
      size="<dtml-var "_.min(7, _.len(_[select_variable]))">"> 

to:

  <select name="<dtml-var id>:utf8:list:<dtml-var
"type_as_string(selectValues)">" 
      multiple size="<dtml-var "_.min(7, _.len(_[select_variable]))">">