dav: Outsource PrincipalResource AT to where it's actually needed

crates/caldav/src/calendar/resource.rs

@@ -100,10 +100,13 @@ impl DavPushExtension for CalendarResource {
     }
 }
 
+impl CommonPropertiesExtension for CalendarResource {
+    type PrincipalResource = PrincipalResource;
+}
+
 impl Resource for CalendarResource {
     type Prop = CalendarPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/caldav/src/calendar_object/resource.rs

@@ -51,10 +51,13 @@ pub struct CalendarObjectResource {
     pub principal: String,
 }
 
+impl CommonPropertiesExtension for CalendarObjectResource {
+    type PrincipalResource = PrincipalResource;
+}
+
 impl Resource for CalendarObjectResource {
     type Prop = CalendarObjectPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/caldav/src/calendar_set/mod.rs

@@ -24,10 +24,13 @@ pub enum PrincipalPropWrapper {
     Common(CommonPropertiesProp),
 }
 
+impl CommonPropertiesExtension for CalendarSetResource {
+    type PrincipalResource = PrincipalResource;
+}
+
 impl Resource for CalendarSetResource {
     type Prop = PrincipalPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/caldav/src/principal/mod.rs

@@ -61,10 +61,13 @@ impl NamedRoute for PrincipalResource {
     }
 }
 
+impl CommonPropertiesExtension for PrincipalResource {
+    type PrincipalResource = Self;
+}
+
 impl Resource for PrincipalResource {
     type Prop = PrincipalPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/carddav/src/address_object/resource.rs

@@ -47,10 +47,13 @@ pub struct AddressObjectResource {
     pub principal: String,
 }
 
+impl CommonPropertiesExtension for AddressObjectResource {
+    type PrincipalResource = PrincipalResource;
+}
+
 impl Resource for AddressObjectResource {
     type Prop = AddressObjectPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/carddav/src/addressbook/resource.rs

@@ -80,10 +80,13 @@ impl DavPushExtension for AddressbookResource {
     }
 }
 
+impl CommonPropertiesExtension for AddressbookResource {
+    type PrincipalResource = PrincipalResource;
+}
+
 impl Resource for AddressbookResource {
     type Prop = AddressbookPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/carddav/src/principal/mod.rs

@@ -70,10 +70,13 @@ impl NamedRoute for PrincipalResource {
     }
 }
 
+impl CommonPropertiesExtension for PrincipalResource {
+    type PrincipalResource = Self;
+}
+
 impl Resource for PrincipalResource {
     type Prop = PrincipalPropWrapper;
     type Error = Error;
-    type PrincipalResource = PrincipalResource;
     type Principal = User;
 
     fn get_resourcetype(&self) -> Resourcetype {

crates/dav/src/extensions/common.rs

@@ -28,6 +28,8 @@ pub enum CommonPropertiesProp {
 }
 
 pub trait CommonPropertiesExtension: Resource {
+    type PrincipalResource: NamedRoute;
+
     fn get_prop(
         &self,
         rmap: &ResourceMap,
@@ -66,5 +68,3 @@ pub trait CommonPropertiesExtension: Resource {
         Err(crate::Error::PropReadOnly)
     }
 }
-
-impl<T: Resource> CommonPropertiesExtension for T {}

crates/dav/src/resource/mod.rs

@@ -26,7 +26,6 @@ impl<T: FromStr> ResourcePropName for T {}
 pub trait Resource: Clone + 'static {
     type Prop: ResourceProp + PartialEq + Clone + EnumVariants + EnumUnitVariants;
     type Error: ResponseError + From<crate::Error>;
-    type PrincipalResource: Resource + NamedRoute;
     type Principal: Principal;
 
     fn get_resourcetype(&self) -> Resourcetype;

crates/dav/src/resources/root.rs

@@ -18,10 +18,13 @@ impl<PR: Resource, P: Principal> Default for RootResource<PR, P> {
     }
 }
 
+impl<PR: Resource + NamedRoute, P: Principal> CommonPropertiesExtension for RootResource<PR, P> {
+    type PrincipalResource = PR;
+}
+
 impl<PR: Resource + NamedRoute, P: Principal> Resource for RootResource<PR, P> {
     type Prop = CommonPropertiesProp;
     type Error = PR::Error;
-    type PrincipalResource = PR;
     type Principal = P;
 
     fn get_resourcetype(&self) -> Resourcetype {