Hi! Actually should answer to these posts... ;-) On Thu, Dec 28, 2000 at 03:11:37PM -0500, Steve Spicklemire wrote:
Hi Christian,
Well, nobody else answered that I saw... so I'll take a crack at your questions....
"CS" == Christian Scholz <cs@comlounge.net> writes:
CS> Hi there!
CS> Finally I managed to get a basic understanding of how to do CS> things with ZPatterns ;-) So seems quite cool :) (and CS> hopefully I find some time to write some basic howto about it)
CS> But I have some little questions:
CS> 1. Is it possible to retrieve the set of known IDs from a CS> specialist? Or would I need to add my own method to it which CS> does this (and change it accordingly if I switch to another CS> storage method)?
If you store persistently you can use the Rack's method:
"defaultRack.getPersistentItemIDs()"
Thanks, also found this out in the meanwhile.
but a couple of notes: 1) this returns a BTree object, not a simple list, so you can't iterate through it in DTML. You'll need to copy it to a simple list for that.. and 2) If you change to a different storage you'll need to create your own method (ZSQL Method?). What I've found is that if you have a large number of objects you'll either want to query a Catalog, or an SQL database to get Ids that match some criteria that limit the number of hits to something that makes sense to display in a browser.
I am now using some method I create inside the specialist for it.
CS> 2. Is it planned to provide something like a virtual folder CS> which acts like a normal object manager but is controlled via CS> ZPatterns (so actually something like Folder with Customizer CS> Support just without the "anchor" in ZODB. (would also CS> require some mechanism asked for in 1.)
Hmmm... I'm not sure what you're after here. Why not just use a Specialist? In what sense do you want it to be virtual?
Well, virtual in the sense as a specialist is no real folder but can provide content from different sources. Thus what I mean is some mechanism which emulates objectIds() etc. so it looks to the user (and the ones using it via dtml) like a normal folder object. Somehow like the Customizer but without the need for actually creating Zope objects. Something inbetween Specialist and Customizer this would be I guess.
(Are you looking for a dynamic traversal interface that would allow you to map URLs to objects that are managed by ZPatterns? Can you give an example?)
yes, something like this comes close I guess. e.g. I have some sql database consisting of people's addresses and I want to create some specialist which queries this database (or how ever this specialist is configured right now in order to get the object ids) and shows it as if it's a normal folder. (seems to me more transparent at some point). But I assume it's not suited for all applications e.g. if the number of objects gets a little bigger. And I guess I can create this myself if I subclass from Specialist and add the rest of the ObjectManager's interface to it.
CS> 3. Is it possible to use ZPatterns also without some exta CS> ZClass defined in a Product? At least if I don't need methods CS> for my objects but simple want to define the attribute they CS> know. Would be nice as I could then hold everything together CS> in one place (the specialist that is) without requiring to CS> install something also in the Products folder of the Control CS> Panel.
I believe you need to either create a Python subclass, or a ZClass subclass of DataSkin. "Raw" DataSkins don't have the right permissions to allow for TTW access. If you're creating a 'product' anyway... just make a 'dummy' class that you can use for storage.
ok, but I still need to define the attributes I want to handle inside a propertysheet of this ZClass, right? Actually what I would like is something which directly resides inside the Specialist and not somewhere outside in some Product folder. So everything is close together in one place.
CS> That's it for now, I will keep experimenting then.. :)
Good Luck!
Oh, it's working better than I thought :) but thanks, christian