Re: [Zope-dev] Converters.field2date, allow empty string to return None?
Brad Clements writes: One thing that has been bothering me is that I can't easily test my ZSQL Methods if they accept a date type unless I completely fill all the date arg types. For example, if the sqlmethod has argument type startdate:date='' and in the body I have dtml-if startdate ... When i use the test form, I can't leave the date field empty, otherwise I get a conversion error from Converters.field2date() One solution would be to use a valid (special) date as default value and test against it in the body. I see that converters required: exists, but does that imply that all other converters allow an empty string to return None? Or do we need to add an explicit "optional" type? I think, we should have an explicit "optional" because that is the most clear way to say, this argument is optional. Dieter ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Converters.field2date, allow empty string to return None?
On 3 Sep 2000, at 13:33, Dieter Maurer wrote: One solution would be to use a valid (special) date as default value and test against it in the body. I don't like this "solution" because the end-user has to know what the special date is, it looks ugly on the form and it still does *not* fix the problem of using the test function in an SQL Method. Brad Clements,[EMAIL PROTECTED] (315)268-1000 http://www.murkworks.com (315)268-9812 Fax netmeeting: ils://ils.murkworks.com AOL-IM: BKClements ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Converters.field2date, allow empty string to return None?
Brad Clements wrote: One thing that has been bothering me is that I can't easily test my ZSQL Methods if they accept a date type unless I completely fill all the date arg types. For example, if the sqlmethod has argument type startdate:date='' and in the body I have dtml-if startdate ... When i use the test form, I can't leave the date field empty, otherwise I get a conversion error from Converters.field2date() I also have this problem with any form that has type date, if the end-user doesn't put a date in the form, I get a conversion error. Its okay with me to receive an empty string, which gets converted to None .. I just put NULL in the sql database. So .. what's the correct fix to allow empty fields to return either '' or None from field2date? I take the form input as a string, and use an intermediate method that checks whether it makes a valid date, and massages it into shape if not. For an empty form field, what is best to do depends on the application. When I'm using PropertySheets, for example, I often use a boolean property called "date_is_known". If the date is left blank, I set the date to 3000-01-01 UTC, and date_is_known to 0. Otherwise, the date gets set appropriately, and date_is_known is set to 1. I set the date so far in advance so that if it inadvertantly creeps into some analysis (because someone forgot to check date_is_known) it will be obvious that something is up. Of course, this does mean that my systems have a year-3000 problem. Perhaps I should use 3 instead? g You can redirect to the form, or an error page, or the form with an error variable set, if the date is not parsable, or not valid for your application. As you're using a SQL database that supports NULL values in date fields, you can obviiously process the results to mean the same thing. Oh, if you're just asking people for a date, rather than a date and time, I'd suggest appending a standard timezone to the date before you store it. Otherwise, you may have problems with days slipping around if your server changes timezone or you enter daylight savings time. This is more of an issue near to the GMT zone. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
[Zope-dev] Converters.field2date, allow empty string to return None?
One thing that has been bothering me is that I can't easily test my ZSQL Methods if they accept a date type unless I completely fill all the date arg types. For example, if the sqlmethod has argument type startdate:date='' and in the body I have dtml-if startdate ... When i use the test form, I can't leave the date field empty, otherwise I get a conversion error from Converters.field2date() I also have this problem with any form that has type date, if the end-user doesn't put a date in the form, I get a conversion error. Its okay with me to receive an empty string, which gets converted to None .. I just put NULL in the sql database. So .. what's the correct fix to allow empty fields to return either '' or None from field2date? I can alter Converters.py... I see that converters required: exists, but does that imply that all other converters allow an empty string to return None? Or do we need to add an explicit "optional" type? Either way, I'd like to fix this, but what's the best way? Brad Clements,[EMAIL PROTECTED] (315)268-1000 http://www.murkworks.com (315)268-9812 Fax netmeeting: ils://ils.murkworks.com AOL-IM: BKClements ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
