On 5 Dec 2003, at 01:39, Richard Unger wrote:
Hi!
I do see the purpose of events, I just think putting themin the webDAV Layer of slide is the wrong place.
Richard, nobody is proposing to add observation at the WebDAV layer. We are proposing adding observability at the Slide Core API part. I really don't see how we can add observability in WebDAV without resorting in some form of BPEL4WS-like complexity. and god: save me from that!
Your file-system under windows or linux does not provide observer-hooks allowing you to veto writes as they occur.
that's exactly one of the reasons file systems are terrible content repositories nowadays (used to be perfect in the '70s, but we have gone a long way since then)
It would be slow, confusing, and ultimately lead to problems as apps vetoed changes they shouldn't, etc...
bah, why?
Here's some examples of how I see this kind of thing working:
Slide needs a presentation and business logic, or workflow, layer on top
of the content repository in order to be a functional CMS.
yep
Typically this would be a web application, and this application can perform checks and verify content before allowing it to be saved on slide.
yep
Additionally, you could set slide up to provide multiple views of the same file system using versioning. Before the HEAD is tagged as stable, releasing it to the public view, the CMS Application can verify the content, and refuse to tag the content if it does not verify. I really like this kind of setup.
sure, staging is one way to deal with this, but it's not the only one. Staging ends up being a "all or nothing" thing. Transactional observability allows a much finer grained control on the content and the actions on it.
If you bypass the CMS application and save directly to the slide system,
using webfolders for example, you are bypassing the checks and
verifications too.
Those who believe to be able a DeltaV auto-versioned repository straight from web folders make me laugh. Auto-versioning is nice on a well-behaving webdav client and almost none are.
Think of it like an IDE, like eclipse - if you dump a
file directly into the workspace using windows explorer or nautilus, you
need to refresh to make eclipse aware of it. You would not want hooks in
Windows Explorer or the file system driver asking eclipse for write
permission first...
I really can't follow you.
There are many places to tackle the events, including slide, but
vetoability is not a good idea. A simple changelistener interface should
be sufficient to avoid having to poll for changes, no?
Of course, polling change is very bad and this will not be done. But a changeListener interface is probably not granular enough. But yeah, it is an addition to the java layer not ot the webdav one.
does this help?
-- Stefano.
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