[Zope3-dev] Re: Field constructors

[Casey Duncan]

On Wed, 14 Jan 2004 16:53:02 +0100
Philipp von Weitershausen <philipp at weitershausen.de> wrote:

> Jim Fulton wrote:
> >  > Ah, well, it's not a big deal really. It's just that you write::
> >  >
> >  >            title = TextLine(
> >  >                __doc__ =
> >  >                """Menu item title
> >  >
> >  >                The title provides the basic label for the menu
> >  >                item.""",
> >  >                required=True.
> >  >                )
> >  >
> >  > while I would prefer the schema convention::
> >  >
> >  >            title = TextLine(
> >  >                title=u"Menu item title",
> >  >                description=u"""The title provides the basic label
> >  >                for the menu item.""",
> >  >                required=True.
> >  >                )
> > 
> > They are equivalent.
> 
> I see the majyck in Field.__init__ now. I'm repelled and attracted at 
> the same time. :)

You took the words right out of my mouth. Part of me likes this idea
another part hates it.
 
> > I find the former more readable.

Maybe (I'm not sure myself), but it certainly make life harder on the
computer.
 
> Whatever happened to explicit is better than implicit? People will
> ask: why that magic? (see i18n issue below).

Yeah, this smells kinda bad. I think it's a slippery slope. Pretty soon
we'll be writing full ReST documents in __doc__ and expecting the right
attributes to automagically parse out of it ;^). Seriously though I
think it sets a bad precident, are these really docstrings?
 
> > I'd actually
> > prefer to be able to write:
> > 
> >            title = TextLine(
> >                """Menu item title
> > 
> >                The title provides the basic label for the menu item.
> >                """,
> >                required=True.
> >                )
> > 
> > This will require a change to the way field constructors are
> > written. :/
> 
> I'm ok with that. The i18n issue remains, though. And I wouldn't want
> to sell a newbie that the Field constructor automatically splits the 
> __doc__ and makes message ids out of the title and description. What 
> domain will it make them for? It'll make the extractor tool a lot more
> 
> complicated as well.
> Maybe I'm overseeing something, but I don't think it'll make our lives
> 
> easier, especially when it's just a cosmetic thing.

i18n issues aside, writing triple-quoted strings as args is strange. Are
you going to strip leading whitespace here? What about trailing
newlines? What happens if I forget the blank line after the title?

How about this:

            title = TextLine(
                """<doc><title>Menu item title</title>
                <description>The title provides the basic 
                label for the menu item.</description></doc>
                """,
                required=True.
                )

And if you like that I have some swamp land in Florida you might be
interested in too ;^)

-Casey