This package provides a support to simplify the use of annotations in Zope.
Setting up grokcore.annotation
This package is essentially set up like the grokcore.component package, please refer to its documentation for details. The only additional ZCML line you will need is:
<include package="grokcore.annotation" />
Put this somewhere near the top of your root ZCML file but below the
line where you include grokcore.component
's configuration.
Example
Here a simple example of use of an annotation:
import grokcore.annotation from zope import interface # Create a model and an interface you want to adapt it to # and an annotation class to implement the persistent adapter. class Mammoth(grokcore.annotation.Model): pass class ISerialBrand(interface.Interface): unique = interface.Attribute("Brands") class Branding(grokcore.annotation.Annotation): grokcore.annotation.implements(ISerialBrand) unique = 0 # Grok the above code, then create some mammoths manfred = Mammoth() mumbles = Mammoth() # creating Annotations work just like Adapters livestock1 = ISerialBrand(manfred) livestock2 = ISerialBrand(mumbles) # except you can store data in them, this data will transparently persist # in the database for as long as the object exists livestock1.unique = 101 livestock2.unique = 102 # attributes not listed in the interface will also be persisted # on the annotation livestock2.foo = "something"
API Overview
Base classes
Annotation
- Base class for an Annotation. Inherits from the persistent.Persistent class.
Model
- Base class for a Model on which you want to use an annotation.
queryAnnotation(model, interface)
- Query the annotation on the given model for the given interface. Return the annotation if found, None otherwise. This will not make any write operation.
deleteAnnotation(model, interface)
- Look for the given annotation and delete it from the model.
LazyAnnotation
- Base class for an annotation. It only writes a database object when explicitly setting values on the lazy properties.
LazyAnnotationProperty
- Property implementation that works with
LazyAnnotation
.
In addition, the grokcore.annotation
package exposes the
grokcore.component API.