Group some DAV properties in extensions

crates/dav/src/extensions/synctoken.rs

@@ -0,0 +1,39 @@
+use rustical_xml::{EnumUnitVariants, EnumVariants, XmlDeserialize, XmlSerialize};
+
+#[derive(XmlDeserialize, XmlSerialize, PartialEq, Clone, EnumUnitVariants, EnumVariants)]
+#[xml(unit_variants_ident = "SyncTokenExtensionPropName")]
+pub enum SyncTokenExtensionProp {
+    // Collection Synchronization (RFC 6578)
+    #[xml(ns = "crate::namespace::NS_DAV")]
+    SyncToken(String),
+
+    // CalendarServer
+    #[xml(ns = "crate::namespace::NS_CALENDARSERVER")]
+    Getctag(String),
+}
+
+pub trait SyncTokenExtension {
+    fn get_synctoken(&self) -> String;
+
+    fn get_prop(
+        &self,
+        prop: &SyncTokenExtensionPropName,
+    ) -> Result<SyncTokenExtensionProp, crate::Error> {
+        Ok(match &prop {
+            SyncTokenExtensionPropName::SyncToken => {
+                SyncTokenExtensionProp::SyncToken(self.get_synctoken())
+            }
+            SyncTokenExtensionPropName::Getctag => {
+                SyncTokenExtensionProp::Getctag(self.get_synctoken())
+            }
+        })
+    }
+
+    fn set_prop(&self, _prop: SyncTokenExtensionProp) -> Result<(), crate::Error> {
+        Err(crate::Error::PropReadOnly)
+    }
+
+    fn remove_prop(&self, _prop: &SyncTokenExtensionPropName) -> Result<(), crate::Error> {
+        Err(crate::Error::PropReadOnly)
+    }
+}