[Zope3-dev] Re: ZCML

[Martijn Faassen]

Shane Hathaway wrote:
> The second thing that bothers me is that some directives use a lot of 
> attributes, and some of those attributes clash in comprehension. 
> "browser:editform" has both a "label" and a "title" attribute, for 
> example.  It turns out that "label" is text describing the form, and 
> "title" is text describing the menu item.  It would be simpler to have a 
> "menu" child element.

And put human-readable text in text nodes, not as attribute values.

> As another example, the following directive is too much to swallow at once:
[snip]
> There are too many concepts mixed in one tag.  It needs to be split up.

I've felt this myself when looking at ZCML. If a tag has more than
7 attributes (or even less) my short-term memory tends to short out. This
means I'll be either referring to the documentation constantly or
that I'll be programming by copy and paste, and I don't like either
way.

The way this can be amended is to introduce a number of very regular
patterns in the XML schema which can be easily generalized. The
overridability you mentioned would also help.

It may be very easy from an implementation point to add new tags and
attributes now. That is good. That's usability for those who need to
extend and maintain ZCML. But usability for those that just use ZCML
is more important still.

Regards,

Martijn