allow for adoption of relations to a predicate interface;

with example implementation for a 'has Role' predicate in loops.organize

CHANGES.txt

@@ -6,6 +6,8 @@ $Id$
 1.1
 ---
 
+- allow for adoption of relations to a predicate interface;
+  with example implementation for a 'has Role' predicate in loops.organize
 - external collection: provide functionality for automatically populate
   meta information of media assets
 - new query for retrieving work items independently of task or user

interfaces.py

@@ -729,6 +729,12 @@ class IPredicate(IConceptSchema):
         required=False)
 
 
+class IRelationAdapter(Interface):
+    """ Base interface for adapters to relations that allow the specification
+        of special properties of a relation.
+    """
+
+
 # probably not useful
 class xxIMappingAttributeRelation(IConceptSchema):
     """ A relation based on a predicate ('mappingAttribute') that provides

organize/README.txt

@@ -390,15 +390,6 @@ Events listing
   >>> list(listing.events())
   [<loops.browser.concept.ConceptRelationView ...>]
 
-Allocation of persons to tasks
-------------------------------
-
-  >>> from loops.organize.interfaces import IAllocated
-  >>> predicate = concepts['predicate']
-  >>> allocated = addAndConfigureObject(concepts, Concept, 'allocated',
-  ...                   title=u'allocated',
-  ...                   conceptType=predicate, predicateInterface=IAllocated)
-
 
 Send Email to Members
 =====================
@@ -423,6 +414,45 @@ Show Presence of Other Users
   >>> component.provideUtility(Presence())
 
 
+Roles of Persons
+================
+
+When persons are assigned to a parent (e.g. an instutution or a project)
+this assignment may be characterized by a certain role. This role may
+be specified by using a special predicate that is associated with a
+predicate interface that allows to specify the role.
+
+(Note that the security-relevant assignment of persons is managed via
+other special predicates: 'ismember', 'ismaster'. The 'hasrole'
+predicate described here is intended for situations where the roles
+may be chosen from an arbitrary list.)
+
+  >>> from loops.organize.interfaces import IHasRole
+  >>> predicate = concepts['predicate']
+  >>> hasRole = addAndConfigureObject(concepts, Concept, 'hasrole',
+  ...                   title=u'has Role',
+  ...                   conceptType=predicate, predicateInterface=IHasRole)
+
+Let's now assign john to task01 and have a look at the relation created.
+
+  >>> task01.assignChild(john, hasRole)
+  >>> relation = task01.getChildRelations([hasRole])[0]
+
+The role may be accessed by getting a relation adapter
+
+  >>> from loops.predicate import adaptedRelation
+  >>> adRelation = adaptedRelation(relation)
+  >>> adRelation.role is None
+  True
+
+  >>> adRelation.role = 'member'
+  >>> relation._role
+  'member'
+  >>> adRelation = adaptedRelation(relation)
+  >>> adRelation.role
+  'member'
+
+
 Calendar
 ========
 

organize/configure.zcml

@@ -39,6 +39,16 @@
              set_schema="loops.organize.interfaces.ITask" />
   </zope:class>
 
+  <zope:adapter factory="loops.organize.party.HasRole"
+                provides="loops.organize.interfaces.IHasRole"
+                trusted="True" />
+  <zope:class class="loops.organize.party.HasRole">
+    <require permission="zope.View"
+             interface="loops.organize.interfaces.IHasRole" />
+    <require permission="zope.ManageContent"
+             set_schema="loops.organize.interfaces.IHasRole" />
+  </zope:class>
+
   <!-- member registration -->
 
   <zope:adapter factory="loops.organize.member.MemberRegistrationManager"

organize/interfaces.py

@@ -1,5 +1,5 @@
 #
-#  Copyright (c) 2009 Helmut Merz helmutm@cy55.de
+#  Copyright (c) 2011 Helmut Merz helmutm@cy55.de
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -32,9 +32,8 @@ from zope.security.proxy import removeSecurityProxy
 from cybertools.organize.interfaces import IAddress as IBaseAddress
 from cybertools.organize.interfaces import IPerson as IBasePerson
 from cybertools.organize.interfaces import ITask
-from loops.interfaces import IConceptSchema
+from loops.interfaces import ILoopsAdapter, IConceptSchema, IRelationAdapter
 from loops.organize.util import getPrincipalFolder
-from loops.interfaces import ILoopsAdapter
 from loops import util
 from loops.util import _
 
@@ -164,19 +163,20 @@ class ITask(IConceptSchema, ITask, ILoopsAdapter):
     pass
 
 
-# 'allocated' predicate
+# 'hasrole' predicate
 
-class IAllocated(IConceptSchema):
+class IHasRole(IRelationAdapter):
 
-    allocType = schema.Choice(
-            title=_(u'Allocation Type'),
+    role = schema.Choice(
+            title=_(u'Role'),
             description=_(u'Specifies the kind of interaction a person or another '
-                    u'party has with the task or project it is allocated to.'),
+                    u'party has with an institution, a task, or a project '
+                    u'it is associated with.'),
             source=util.KeywordVocabulary((
-                    ('standard', _(u'Standard')),
+                    ('member', _(u'Member')),
                     ('master', _(u'Master')),
                 )),
-            default='standard',
+            default='member',
             required=True)
 
 

organize/party.py

@@ -1,5 +1,5 @@
 #
-#  Copyright (c) 2009 Helmut Merz helmutm@cy55.de
+#  Copyright (c) 2011 Helmut Merz helmutm@cy55.de
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -40,8 +40,9 @@ from cybertools.typology.interfaces import IType
 from loops.common import AdapterBase
 from loops.concept import Concept
 from loops.interfaces import IConcept
-from loops.organize.interfaces import IAddress, IPerson, IAllocated
+from loops.organize.interfaces import IAddress, IPerson, IHasRole
 from loops.organize.interfaces import ANNOTATION_KEY
+from loops.predicate import RelationAdapter
 from loops.security.common import assignOwner, removeOwner, allowEditingForOwner
 from loops.type import TypeInterfaceSourceList
 from loops.predicate import PredicateInterfaceSourceList
@@ -51,7 +52,7 @@ from loops import util
 # register type interfaces - (TODO: use a function for this)
 
 TypeInterfaceSourceList.typeInterfaces += (IPerson, IAddress)
-PredicateInterfaceSourceList.typeInterfaces += (IAllocated,)
+PredicateInterfaceSourceList.predicateInterfaces += (IHasRole,)
 
 
 def getPersonForUser(context, request=None, principal=None):
@@ -177,3 +178,11 @@ class Address(AdapterBase):
         self.context._lines = value
     lines = property(getLines, setLines)
 
+
+class HasRole(RelationAdapter):
+    """ Allows specification of a role for a relation.
+    """
+
+    implements(IHasRole)
+
+    _contextAttributes = list(IHasRole)

organize/tests.py

@@ -23,8 +23,8 @@ from zope.app.securitypolicy.interfaces import IPrincipalRoleManager
 from cybertools.util.jeep import Jeep
 from loops.common import adapted
 from loops.concept import Concept
-from loops.organize.interfaces import IPerson
-from loops.organize.party import Person
+from loops.organize.interfaces import IPerson, IHasRole
+from loops.organize.party import Person, HasRole
 from loops.organize.task import Task
 from loops.setup import addAndConfigureObject
 from loops.tests.auth import login
@@ -38,6 +38,7 @@ def setupUtilitiesAndAdapters(loopsRoot):
     component.provideAdapter(Person, provides=IPerson)
     component.provideAdapter(Task)
     component.provideAdapter(FoundPrincipalFactory)
+    component.provideAdapter(HasRole, provides=IHasRole)
     return Jeep((
             ('auth', auth),
             ('principalAnnotations', principalAnnotations),

predicate.py

@@ -30,10 +30,10 @@ from zope.dottedname.resolve import resolve
 from zope.security.proxy import removeSecurityProxy
 from zope.traversing.api import getName
 
-from loops.interfaces import ILoopsObject, IConcept, IResource
-from loops.interfaces import IPredicate #, IMappingAttributeRelation
+from loops.interfaces import ILoopsObject, IConcept, IResource, IConceptRelation
+from loops.interfaces import IPredicate, IRelationAdapter #, IMappingAttributeRelation
 from loops.concept import Concept
-from loops.common import AdapterBase
+from loops.common import adapted, AdapterBase
 from loops.type import TypeInterfaceSourceList
 
 
@@ -60,12 +60,36 @@ class PredicateInterfaceSourceList(TypeInterfaceSourceList):
         may be used for specifying additional attributes of relations.
     """
 
-    typeInterfaces = ()
+    predicateInterfaces = ()
+
+    @property
+    def typeInterfaces(self):
+        return self.predicateInterfaces
+
+
+class RelationAdapter(AdapterBase):
+    """ Base class for adapters to relations that may be used for
+        specifying additional attributes for relations.
+    """
+
+    implements(IRelationAdapter)
+    adapts(IConceptRelation)
+
+
+def adaptedRelation(relation):
+    if isinstance(relation, RelationAdapter):
+        return obj
+    ifc = adapted(relation.predicate).predicateInterface
+    if ifc is not None:
+        adRelation = component.queryAdapter(relation, ifc)
+        if adRelation is not None:
+            return adRelation
+    return relation
 
 
 # standard relation adapters
 
-#PredicateInterfaceSourceList.typeInterfaces += (IMappingAttributeRelation,)
+#PredicateInterfaceSourceList.predicateInterfaces += (IMappingAttributeRelation,)
 
 
 #class MappingAttributeRelation(AdapterBase):