Quickie on ZPatterns ... I promise :)
Let's say I have an object I will store in a rack. Let us say I want this object to be cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)= Bill -- Do not meddle in the affairs of sysadmins, for they are easy to annoy, and have the root password.
Bill Anderson wrote:
Let's say I have an object I will store in a rack. Let us say I want this object to be cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)=
You can't have them inherit from CatalogAware, you'll need to use a trigger that does this for you. I'm uploading a Product that gives this capability - and unlike CatalogAware, it recatalogs *automatically* whenever the object changes. No more object_reindex! (I only tested extensively with DataSkins, though). http://www.zope.org/Members/itamar/ZPAddons -- Itamar S.T. itamar@maxnm.com Fingerprint = D365 7BE8 B81E 2B18 6534 025E D0E7 92DB E441 411C
Itamar Shtull-Trauring wrote:
Bill Anderson wrote:
Let's say I have an object I will store in a rack. Let us say I want this object to be cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)=
You can't have them inherit from CatalogAware, you'll need to use a trigger that does this for you. I'm uploading a Product that gives this capability - and unlike CatalogAware, it recatalogs *automatically* whenever the object changes. No more object_reindex! (I only tested extensively with DataSkins, though).
Cool! I'll check it out today/tomorrow. Now if only I could figure out how to change user.__roles in Membership, I'd have a really cool Memebrship Release ready :-) -- Do not meddle in the affairs of sysadmins, for they are easy to annoy, and have the root password.
Bill Anderson wrote:
Let's say I have an object I will store in a rack. Let us say I want this object to be cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)=
Make one of the object's base-classes DataSkin. Don't make it CatalogAware. Use triggers to index and unindex the object from a catalog. You'll probably want to store the catalog in Specialist. By the way, Phillip Eby has released a new development snapshot: http://www.zope.org/Members/pje/ZPatterns/ZPatterns-0-4-1snap1.tgz/view I'll be trying it later today. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net
Steve Alexander wrote:
Bill Anderson wrote:
Let's say I have an object I will store in a rack. Let us say I want this object to be cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)=
Make one of the object's base-classes DataSkin.
Don't make it CatalogAware.
that was my hunch ...
Use triggers to index and unindex the object from a catalog. You'll probably want to store the catalog in Specialist.
OK, guess it's sime to learn triggers ;-)
By the way, Phillip Eby has released a new development snapshot:
http://www.zope.org/Members/pje/ZPatterns/ZPatterns-0-4-1snap1.tgz/view
I'll be trying it later today.
Likewise. Gotta see how/if it works with membership.
-- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net
-- Do not meddle in the affairs of sysadmins, for they are easy to annoy, and have the root password.
At 09:15 AM 7/27/00 +0100, Steve Alexander wrote:
Bill Anderson wrote:
Let's say I have an object I will store in a rack. Let us say I want
this object to be
cataloged in a ZCatalog. Any caveats I need to know about ..such as "Don't do that!" ? ?;^)=
Make one of the object's base-classes DataSkin.
Don't make it CatalogAware.
Use triggers to index and unindex the object from a catalog. You'll probably want to store the catalog in Specialist.
By the way, Phillip Eby has released a new development snapshot:
http://www.zope.org/Members/pje/ZPatterns/ZPatterns-0-4-1snap1.tgz/view
I'll be trying it later today.
FYI, the snapshot really only adds proxy roles support for generic providers/triggers, and adds a first-cut version of SkinScript. If you're adventurous, you can look at SkinScript/Compiler.py and have a look at the grammar in order to figure out what the language does. So far I've successfully tested a SkinScript method that does the work of four GenericAttributeProviders and two GenericTriggers, just by using the appropriate statements. Here's a SkinScript snippet you might use for CatalogAwareness: WHEN OBJECT ADDED CALL somecatalog.catalog_object(self) WHEN OBJECT CHANGED CALL somecatalog.recatalog_object(self) WHEN OBJECT DELETED CALL somecatalog.uncatalog_object(self) (Replace the incorrect catalog API calls with ones that are correct... I'm sure I'm missing some parameters and probably getting the names wrong...) Note that "somecatalog" must be in the acquisition context of the SkinScript method itself. If you want to use a catalog in the context of the DataSkin, you need to say "self.somecatalog...". Some other SkinScript snippets: # Store attribs persistently - replaces # Persistent Internal Attribute Provider STORE attrib1,attrib2 IN SELF # Computed attributes WITH SELF COMPUTE attrib1=attrib2+attrib3, attrib4=attrib6*10 # Generic attrib provider WITH (SomeSQLMethod(key=self.id) or [NOT_FOUND])[0] COMPUTE field1, field2, somefield=field3+field4, fancy_id = '*(%s%s)%' % (otherfield,self.id) # Generic trigger WHEN OBJECT ADDED,CHANGED,DELETED CALL someexpr(self.id) SAVING foo,bar, baz=spam, widget=diddly+id # Attribute provider STORE attr1,attr2 USING somefunc(self) SAVING attr1,attr2 # Conditional attrib provider WHEN OBJECT ADDED STORE attr2 USING otherfunc(self) That about covers it for what's implemented so far. The goal is to ultimately replace the majority of providers and triggers with SkinScript. But it will still be possible to write and use custom plug-ins that provide attributes or handle events in other ways. But SkinScript will be quite handy for most things.
participants (4)
-
Bill Anderson -
Itamar Shtull-Trauring -
Phillip J. Eby -
Steve Alexander