[Zope3-checkins] CVS: Zope3/src/zope/app/index - __init__.py:1.3

[Anthony Baxter]

Update of /cvs-repository/Zope3/src/zope/app/index
In directory cvs.zope.org:/tmp/cvs-serv24050/app/index

Modified Files:
	__init__.py 
Log Message:
Refactoring of the Catalog<->Index interface to extract common code. 

TextIndexes now index a particular interface+field combination, which 
defaults to ISearchableText/getSearchText. Making a new index hook into
the catalog is now a matter of two or three lines of python and some 
zcml.


=== Zope3/src/zope/app/index/__init__.py 1.2 => 1.3 ===
--- Zope3/src/zope/app/index/__init__.py:1.2	Wed Dec 25 09:12:54 2002
+++ Zope3/src/zope/app/index/__init__.py	Tue Aug  5 04:33:24 2003
@@ -1,2 +1,68 @@
 #
 # This file is necessary to make this directory a package.
+
+from zope.interface import implements
+from zope.app.interfaces.index import IInterfaceIndexer
+from zope.app.interfaces.event import ISubscriber
+from zope.component import queryAdapter
+from zope.context import ContextMethod
+
+from zope.app.interfaces.services.hub import \
+     IRegistrationHubEvent, \
+     IObjectRegisteredHubEvent, \
+     IObjectUnregisteredHubEvent, \
+     IObjectModifiedHubEvent
+
+
+class InterfaceIndexingSubscriber(object):
+    """Mixin for indexing a particular field name, after first adapting the
+       object to be indexed to an interface.
+    """
+    implements(IInterfaceIndexer, ISubscriber)
+    default_field_name = None
+    default_interface = None
+
+    def __init__(self, field_name=None, interface=None):
+        super(InterfaceIndexingSubscriber, self).__init__()
+        if field_name is None and self.default_field_name is None:
+            raise ValueError, "Must pass a field_name"
+        if field_name is None:
+            self._field_name = self.default_field_name
+        else:
+            self._field_name = field_name
+        if interface is None:
+            self._interface = self.default_interface
+        else:
+            self._interface = interface
+
+    field_name = property(lambda self: self._field_name)
+    interface = property(lambda self: self._interface)
+
+    def _getValue(self, object):
+        if self._interface is not None:
+            object = queryAdapter(object, self._interface)
+            if object is None: return None
+
+        value = getattr(object, self._field_name, None)
+        if value is None: return None
+
+        if callable(value):
+            try: value = value()
+            except: return None
+
+        return value
+
+    def notify(self, event):
+        """An event occurred.  Index or unindex the object in response."""
+        if (IObjectRegisteredHubEvent.isImplementedBy(event) or
+            IObjectModifiedHubEvent.isImplementedBy(event)):
+            value = self._getValue(event.object)
+            if value is not None:
+                self.index_doc(event.hubid, value)
+        elif IObjectUnregisteredHubEvent.isImplementedBy(event):
+            try:
+                self.unindex_doc(event.hubid)
+            except KeyError:
+                pass
+    notify = ContextMethod(notify)
+