[Zope-dev] ZPatterns Image Archive Project

[Michael R. Bernstein]

"Phillip J. Eby" wrote:
> 
> By the way, RenderingKinds is a sort of specialist that hasn't been
> discussed much outside of the apps Ty and I work with - the "constant"
> Specialist, one which contains application configuration or metadata rather
> than "content".  Oftentimes it's handy to simply base a Specialist on a
> TinyTable or similar product in order to set up configuration of constant
> items like RenderingKinds.  Consider the TinyTable data below:
> 
> Columns: name:string scaling:float width:int height:int rackname:string
> 
> "fullsize",1.0,0,0,"bigimages"
> "halfsize",0.5,0,0,"bigimages"
> "thumbnail",0.0,64,64,"thumbnails"

In my application, I'm only interested in specifying the
'maximum dimension' in any direction. This seems to work
better generally, because it accounts automatically for
images that are landscape or portrait oriented. So my
TinyTable only has two columns:

Columns: name:string maxdimension:int

> The RenderingKinds specialist would have a single rack, which uses
> SkinScript to pull in the data from the TinyTable (WITH
> theTinyTable[self.id] COMPUTE scaling,width,height,rackname).

The SkinScript (which I placed in the RenderingKinds
Specialist, not in it's defaultRack) has the following line
in it:

WITH sizes[self.id] COMPUTE maxdimension

I eliminated the 'rackname' column, because you reccomended
that all Renderings(RackImages) be stored in the same Rack,
for simplicity. This also seems the more flexible approach
(ie. I don't have to create management screens to add and
delete racks when the sizes change), so there is less
'hardwiring'.

Now, am I correct in assuming that the 'sizes' TinyTable
should be in the RenderingKinds Specialist?

I'm also assuming that RenderingKinds' defaultRack is set to
use 'ZPatterns: DataSkin' and be set to load by accessing
the 'id' attribute. Is this correct?

Thanks,

Michael Bernstein.