A nice ‘gotcha’ is the distinction between Zope’s schema.Date and schema.Datetime. The difference is obvious and straightforward when the two terms are laid out side-by-side: one is for dates only and the other adds a time component. Where things fell down for me in my usage of these fields with a Dexterity-based content type in Plone is the human component. When these fields are mashed in together within a lot of other text/Python/names, it’s easy to miss those 4 little letters of ‘time’. This lead me trying to use a DatetimeFieldWidget when I really could only use a DateFieldWidget. Wrong widget for the wrong type = unpredictable. (more…)

Today, we’re looking at how to utilise computed fields within a Dexterity-based content type. The specific use-case is that of having two separate fields (first name and surname, for a Person type, for example) generate the complete object title. The first part of this — having the title of the content displayed correctly — is pretty straight forward once you know what documentation to read and understand how things happen. The second part — having the ID of the content correctly generated to be first name/surname is slightly more complicated. (more…)