[Zope-CMF] Re: [dev] RFC: rethinking GenericSetup extension profiles

[yuppie]

Hi Tres!


Tres Seaver wrote:
> 
> I'll note that my original architecture document[1] contemplated two
> kinds of "add-on" profiles:
> 
>   - ExtensionProfiles could register *new* kinds of steps, as well as
>     making non-destructive insertions to the configuration created by a
>     baseline profile.
> 
>   - DeltaProfiles essentially captured line-level diffs to a "baseline"
>     profile.
> 
> I think there is room for both, where we get away from the need to make
> EPs the "current" profile in order to use them.  DeltaProfiles could be
> "applied" by patching a snapshot, and then installing the snapshot as a
> new baseline.
> 
> Because not all the files being patched are XML, I don't think we can or
> should rely on XSLT:  diff might be enough.

I don't know if we have the resources to implement XSLT diffs and of 
course XSLT makes only sense for XML (we can still use diff for other 
files). But for XML XSLT has big advantages over normal diffs:

- normal diffs for XML files are often very hard to read and edit

- small changes in the XML file often make it impossible to apply a 
normal diff

So the use cases for these DeltaProfiles are very limited. Using XSLT 
would allow us to unify DeltaProfiles and ExtensionProfiles, providing 
an automated way for creating ExtensionProfiles.


Cheers,

	Yuppie