Generate fetched results controllers for to-many relationships

This are generated when `frc=true` is used as a template variable.

The cache name is generated from a combination of the entity name, indexed attributes, relationship name and sort descriptors to try to make it unique.

If there are no indexed attributes, the cache name is nil because using different fetch requests with the same cache name completely borks the fetched results controller.

templates/machine.h.motemplate

@@ -73,6 +73,15 @@ extern const struct <$managedObjectClassName$>FetchedProperties {<$foreach Fetch
 <$foreach FetchedProperty noninheritedFetchedProperties do$>
 @property (nonatomic, readonly) NSArray *<$FetchedProperty.name$>;
 <$endforeach do$>
+<$if TemplateVar.frc$>
+#if TARGET_OS_IPHONE
+<$foreach Relationship noninheritedRelationships do$>
+<$if Relationship.isToMany$>
+- (NSFetchedResultsController *)new<$Relationship.name.initialCapitalString$>FetchedResultsControllerWithSortDescriptors:(NSArray *)sortDescriptors;
+<$endif$>
+<$endforeach do$>
+#endif
+<$endif$>
 @end
 
 @interface _<$managedObjectClassName$> (CoreDataGeneratedAccessors)

templates/machine.m.motemplate

@@ -189,4 +189,27 @@ const struct <$managedObjectClassName$>FetchedProperties <$managedObjectClassNam
 }
 <$endif$>
 <$endforeach do$>
+<$if TemplateVar.frc$>
+#if TARGET_OS_IPHONE
+<$foreach Relationship noninheritedRelationships do$>
+<$if Relationship.isToMany$>
+- (NSFetchedResultsController *)new<$Relationship.name.initialCapitalString$>FetchedResultsControllerWithSortDescriptors:(NSArray *)sortDescriptors {
+	NSFetchRequest *fetchRequest = [NSFetchRequest new];
+	<$if !TemplateVar.frc$>[fetchRequest autorelease];<$endif$>
+	fetchRequest.entity = [NSEntityDescription entityForName:@"<$Relationship.destinationEntity.name$>" inManagedObjectContext:self.managedObjectContext];
+	fetchRequest.predicate = [NSPredicate predicateWithFormat:@"<$Relationship.inverseRelationship.name$> <$if Relationship.inverseRelationship.isToMany$>CONTAINS<$else$>==<$endif$> %@", self];
+	fetchRequest.sortDescriptors = sortDescriptors;
+	NSArray *indexedIDs = [NSArray arrayWithObjects:<$foreach Attribute noninheritedAttributes do$><$if Attribute.isIndexed$>self.<$Attribute.name$>, <$endif$><$endforeach do$>nil];
+	NSString *cacheName = nil;
+	if ([indexedIDs count] > 0)
+		cacheName = [NSString stringWithFormat:@"mogenerator.<$managedObjectClassName$>.%@.<$Relationship.name$>.%@", indexedIDs, sortDescriptors];
+	return [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
+											   managedObjectContext:self.managedObjectContext
+												 sectionNameKeyPath:nil
+														  cacheName:cacheName];
+}
+<$endif$>
+<$endforeach do$>
+#endif
+<$endif$>
 @end