Refactor encoder+decoder WIP (compile)

9 files changed, 677 insertions, 435 deletions

diff --git a/src/dav/calencoder.rs b/src/dav/calencoder.rs
index db7ece4..80b8656 100644
--- a/src/dav/calencoder.rs
+++ b/src/dav/calencoder.rs
@@ -1,3 +1,4 @@
+/*
 use super::encoder::{QuickWritable, Context};
 use super::caltypes::*;
 use super::types::Extension;
@@ -893,3 +894,4 @@ mod tests {
         assert_eq!(&got, expected, "\n---GOT---\n{got}\n---EXP---\n{expected}\n");
     }
 }
+*/
diff --git a/src/dav/caltypes.rs b/src/dav/caltypes.rs
index 7131ec2..c8177e9 100644
--- a/src/dav/caltypes.rs
+++ b/src/dav/caltypes.rs
@@ -1,7 +1,8 @@
 #![allow(dead_code)]
 
+/*
 use chrono::{DateTime,Utc};
-use super::types as Dav;
+use super::types as dav;
 
 //@FIXME ACL (rfc3744) is missing, required
 //@FIXME Versioning (rfc3253) is missing, required
@@ -11,15 +12,6 @@ use super::types as Dav;
 // For reference, non-official extensions documented by SabreDAV:
 // https://github.com/apple/ccs-calendarserver/tree/master/doc/Extensions
 
-pub struct CalExtension {
-    pub root: bool
-}
-impl Dav::Extension for CalExtension {
-    type Error = Violation;
-    type Property = Property;
-    type PropertyRequest = PropertyRequest; 
-    type ResourceType = ResourceType;
-}
 
 // ----- Root elements -----
 
@@ -35,7 +27,7 @@ impl Dav::Extension for CalExtension {
 /// instruction in Section 12.13.2 of [RFC2518].
 ///
 /// <!ELEMENT mkcalendar (DAV:set)>
-pub struct MkCalendar<E: Dav::Extension>(pub Dav::Set<E>);
+pub struct MkCalendar<E: dav::Extension>(pub dav::Set<E>);
 
 
 /// If a response body for a successful request is included, it MUST
@@ -51,7 +43,7 @@ pub struct MkCalendar<E: Dav::Extension>(pub Dav::Set<E>);
 /// Definition:
 ///
 /// <!ELEMENT mkcol-response (propstat+)>
-pub struct MkCalendarResponse<T: Dav::Extension>(pub Vec<Dav::PropStat<T>>);
+pub struct MkCalendarResponse<E: dav::Extension>(pub Vec<dav::PropStat<E>>);
 
 // --- (REPORT PART) ---
 
@@ -68,8 +60,8 @@ pub struct MkCalendarResponse<T: Dav::Extension>(pub Vec<Dav::PropStat<T>>);
 /// <!ELEMENT calendar-query ((DAV:allprop |
 ///                            DAV:propname |
 ///                            DAV:prop)?, filter, timezone?)>
-pub struct CalendarQuery<T: Dav::Extension> {
-    pub selector: Option<CalendarSelector<T>>,
+pub struct CalendarQuery<E: dav::Extension> {
+    pub selector: Option<CalendarSelector<E>>,
     pub filter: Filter,
     pub timezone: Option<TimeZone>,
 }
@@ -88,9 +80,9 @@ pub struct CalendarQuery<T: Dav::Extension> {
 /// <!ELEMENT calendar-multiget ((DAV:allprop |
 ///                               DAV:propname |
 ///                               DAV:prop)?, DAV:href+)>
-pub struct CalendarMultiget<T: Dav::Extension> {
-    pub selector: Option<CalendarSelector<T>>,
-    pub href: Vec<Dav::Href>,
+pub struct CalendarMultiget<E: dav::Extension> {
+    pub selector: Option<CalendarSelector<E>>,
+    pub href: Vec<dav::Href>,
 }
 
 /// Name:  free-busy-query
@@ -1056,10 +1048,10 @@ pub struct LimitRecurrenceSet(pub DateTime<Utc>, pub DateTime<Utc>);
 pub struct LimitFreebusySet(pub DateTime<Utc>, pub DateTime<Utc>);
 
 /// Used by CalendarQuery & CalendarMultiget
-pub enum CalendarSelector<T: Dav::Extension> {
+pub enum CalendarSelector<E: dav::Extension> {
     AllProp,
     PropName,
-    Prop(Dav::PropName<T>),
+    Prop(dav::PropName<E>),
 }
 
 /// Name:  comp-filter
@@ -1402,4 +1394,4 @@ impl Collation {
             Self::Unknown(c) => c.as_str(),
         }
     }
-}
+}*/
diff --git a/src/dav/decoder.rs b/src/dav/decoder.rs
index 719ea8c..1756464 100644
--- a/src/dav/decoder.rs
+++ b/src/dav/decoder.rs
@@ -8,33 +8,32 @@ use quick_xml::reader::NsReader;
 use tokio::io::AsyncBufRead;
 
 use super::types::*;
+use super::error::*;
 
-#[derive(Debug)]
-pub enum ParsingError {
-    NamespacePrefixAlreadyUsed,
-    WrongToken,
-    TagNotFound,
-    QuickXml(quick_xml::Error), 
-    Eof
+/*
+// --- Traits ----
+
+trait Reader = AsyncBufRead+Unpin+'static;
+
+trait Decodable: Extension {
+    async fn decode_propreq(xml: &mut PeekRead<impl Reader>) -> Result<Option<Self::PropertyRequest>, ParsingError>;
 }
-impl From<AttrError> for ParsingError {
-    fn from(value: AttrError) -> Self {
-        Self::QuickXml(value.into())
+impl Decodable for NoExtension {
+    async fn decode_propreq(xml: &mut PeekRead<impl Reader>) -> Result<Option<Disabled>, ParsingError> {
+        Ok(None)
     }
 }
-impl From<quick_xml::Error> for ParsingError {
-    fn from(value: quick_xml::Error) -> Self {
-        Self::QuickXml(value)
-    }
+
+pub trait QReadable<T: Reader>: Sized {
+    async fn read(xml: &mut PeekRead<T>) -> Result<Self, ParsingError>;
 }
 
+// --- Peek read with namespaces
+
 const DAV_URN: &[u8] = b"DAV:";
 const CALDAV_URN: &[u8] = b"urn:ietf:params:xml:ns:caldav";
 const CARDDAV_URN: &[u8] = b"urn:ietf:params:xml:ns:carddav";
 //const XML_URN: &[u8] = b"xml";
-
-trait Reader = AsyncBufRead+Unpin+'static;
-
 pub struct PeekRead<T: Reader> {
     evt: Event<'static>,
     rdr: NsReader<T>,
@@ -117,11 +116,9 @@ impl<T: Reader> PeekRead<T> {
     }
 }
 
-pub trait QReadable<T: Reader>: Sized {
-    async fn read(xml: &mut PeekRead<T>) -> Result<Self, ParsingError>;
-}
+// ----- Decode ----
 
-impl<E: Extension, T: Reader> QReadable<T> for PropFind<E> {
+impl<E: Decodable, T: Reader> QReadable<T> for PropFind<E> {
     async fn read(xml: &mut PeekRead<T>) -> Result<PropFind<E>, ParsingError> {
         // Find propfind
         xml.tag_start(DAV_URN, "propfind").await?;
@@ -161,13 +158,13 @@ impl<E: Extension, T: Reader> QReadable<T> for PropFind<E> {
 }
 
 
-impl<E: Extension, T: Reader> QReadable<T> for Include<E> {
+impl<E: Decodable, T: Reader> QReadable<T> for Include<E> {
     async fn read(xml: &mut PeekRead<T>) -> Result<Include<E>, ParsingError> {
         xml.tag_start(DAV_URN, "include").await?;
         let mut acc: Vec<PropertyRequest<E>> = Vec::new();
         loop {
             match xml.peek() {
-                Event::Start(_) => acc.push(PropertyRequest::read(xml).await?),
+                Event::Start(_) | Event::Empty(_) => acc.push(PropertyRequest::read(xml).await?),
                 Event::End(_) if xml.is_tag(DAV_URN, "include") => break,
                 _ => { xml.skip().await?; },
             }
@@ -177,13 +174,13 @@ impl<E: Extension, T: Reader> QReadable<T> for Include<E> {
     }
 }
 
-impl<E: Extension, T: Reader> QReadable<T> for PropName<E> {
+impl<E: Decodable, T: Reader> QReadable<T> for PropName<E> {
     async fn read(xml: &mut PeekRead<T>) -> Result<PropName<E>, ParsingError> {
         xml.tag_start(DAV_URN, "prop").await?;
         let mut acc: Vec<PropertyRequest<E>> = Vec::new();
         loop {
             match xml.peek() {
-                Event::Start(_) => acc.push(PropertyRequest::read(xml).await?),
+                Event::Start(_) | Event::Empty(_) => acc.push(PropertyRequest::read(xml).await?),
                 Event::End(_) if xml.is_tag(DAV_URN, "prop") => break,
                 _ => { xml.skip().await?; },
             }
@@ -193,12 +190,52 @@ impl<E: Extension, T: Reader> QReadable<T> for PropName<E> {
     }
 }
 
-impl<E: Extension, T: Reader> QReadable<T> for PropertyRequest<E> {
+impl<E: Decodable, T: Reader> QReadable<T> for PropertyRequest<E> {
     async fn read(xml: &mut PeekRead<T>) -> Result<PropertyRequest<E>, ParsingError> {
-        /*match xml.peek() {
-            
-        }*/
-        unimplemented!();
+        loop {
+            let (need_close, bs) = match xml.peek() {
+                Event::Start(b) => (true, b),
+                Event::Empty(b) => (false, b),
+                _ => { 
+                    xml.skip().await?; 
+                    continue
+                },
+            };
+
+            let mut maybe_res = None;
+
+            // Option 1: a pure DAV property
+            let (ns, loc) = xml.rdr.resolve_element(bs.name());
+            if matches!(ns, Bound(Namespace(ns)) if ns == DAV_URN) {
+                maybe_res = match loc.into_inner() {
+                    b"creationdate" => Some(PropertyRequest::CreationDate),
+                    b"displayname" => Some(PropertyRequest::DisplayName),
+                    b"getcontentlanguage" => Some(PropertyRequest::GetContentLanguage),
+                    b"getcontentlength" => Some(PropertyRequest::GetContentLength),
+                    b"getetag" => Some(PropertyRequest::GetEtag),
+                    b"getlastmodified" => Some(PropertyRequest::GetLastModified),
+                    b"lockdiscovery" => Some(PropertyRequest::LockDiscovery),
+                    b"resourcetype" => Some(PropertyRequest::ResourceType),
+                    b"supportedlock" => Some(PropertyRequest::SupportedLock),
+                    _ => None,
+                };
+            }
+
+            // Option 2: an extension property
+            if maybe_res.is_none() {
+                maybe_res = E::decode_propreq(xml).await?.map(PropertyRequest::Extension);
+            }
+
+            // In any cases, we must close the opened tag
+            if need_close {
+                xml.skip().await?; 
+            }
+
+            // Return if something is found - otherwise loop
+            if let Some(res) = maybe_res {
+                return Ok(res)
+            }
+        }
     }
 }
 
@@ -207,7 +244,7 @@ mod tests {
     use super::*;
 
     #[tokio::test]
-    async fn basic_propfind() {
+    async fn basic_propfind_propname() {
         let src = r#"<?xml version="1.0" encoding="utf-8" ?>
 <rando/>
 <garbage><old/></garbage>
@@ -220,4 +257,37 @@ mod tests {
         let got = PropFind::<NoExtension>::read(&mut rdr).await.unwrap();
         assert!(matches!(got, PropFind::PropName));
     }
+/*
+    #[tokio::test]
+    async fn basic_propfind_prop() {
+        let src = r#"<?xml version="1.0" encoding="utf-8" ?>
+<rando/>
+<garbage><old/></garbage>
+<D:propfind xmlns:D="DAV:">
+    <D:prop>
+        <displayname/>
+        <getcontentlength/>
+        <getcontenttype/>
+        <getetag/>
+        <getlastmodified/>
+        <resourcetype/>
+        <supportedlock/>
+    </D:prop>
+</D:propfind>
+"#;
+
+        let mut rdr = PeekRead::new(NsReader::from_reader(src.as_bytes())).await.unwrap();
+        let got = PropFind::<NoExtension>::read(&mut rdr).await.unwrap();
+        assert_eq!(got, PropFind::Prop(PropName(vec![
+            PropertyRequest::DisplayName,
+            PropertyRequest::GetContentLength,
+            PropertyRequest::GetContentType,
+            PropertyRequest::GetEtag,
+            PropertyRequest::GetLastModified,
+            PropertyRequest::ResourceType,
+            PropertyRequest::SupportedLock,
+        ])));
+    }
+    */
 }
+*/
diff --git a/src/dav/encoder.rs b/src/dav/encoder.rs
index 7778d61..745c396 100644
--- a/src/dav/encoder.rs
+++ b/src/dav/encoder.rs
@@ -2,390 +2,339 @@ use std::io::Cursor;
 
 use quick_xml::Error as QError;
 use quick_xml::events::{Event, BytesEnd, BytesStart, BytesText};
-use quick_xml::writer::{ElementWriter, Writer};
+use quick_xml::writer::ElementWriter;
 use quick_xml::name::PrefixDeclaration;
 use tokio::io::AsyncWrite;
 use super::types::*;
+use super::xml::{Writer,QWrite,IWrite};
 
 
-//-------------- TRAITS ----------------------
-
-/// Basic encode trait to make a type encodable
-pub trait QuickWritable<C: Context> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError>; 
-}
-
-/// Encoding context
-pub trait Context: Extension {
-    fn child(&self) -> Self;
-    fn create_dav_element(&self, name: &str) -> BytesStart;
-    async fn hook_error(&self, err: &Self::Error, xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError>;
-    async fn hook_property(&self, prop: &Self::Property, xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError>;
-    async fn hook_propertyrequest(&self, prop: &Self::PropertyRequest, xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError>;
-    async fn hook_resourcetype(&self, prop: &Self::ResourceType, xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError>;
-}
-
-/// -------------- NoExtension Encoding Context
-impl Context for NoExtension {
-    fn child(&self) -> Self {
-        Self { root: false }
-    }
-    fn create_dav_element(&self, name: &str) -> BytesStart {
-        let mut start = BytesStart::new(format!("D:{}", name));
-        if self.root {
-            start.push_attribute(("xmlns:D", "DAV:"));
-        }
-        start
-    }
-    async fn hook_error(&self, _err: &Disabled, _xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError> {
-        unreachable!();
-    }
-    async fn hook_property(&self, _prop: &Disabled, _xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError> {
-        unreachable!();
-    }
-    async fn hook_propertyrequest(&self, _prop: &Disabled, _xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError> {
-        unreachable!();
-    }
-    async fn hook_resourcetype(&self, _restype: &Disabled, _xml: &mut Writer<impl AsyncWrite+Unpin>) -> Result<(), QError> {
-        unreachable!();
-    }
-}
-
-
-//--------------------- ENCODING --------------------
-
 // --- XML ROOTS
 
 /// PROPFIND REQUEST
-impl<C: Context> QuickWritable<C> for PropFind<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("propfind");
+impl<E: Extension> QWrite for PropFind<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("propfind");
         let end = start.to_end();
-        let ctx = ctx.child();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
-            Self::PropName => xml.write_event_async(Event::Empty(ctx.create_dav_element("propname"))).await?,
+            Self::PropName => {
+                let empty_propname = xml.create_dav_element("propname");
+                xml.q.write_event_async(Event::Empty(empty_propname)).await?
+            },
             Self::AllProp(maybe_include) => {
-                xml.write_event_async(Event::Empty(ctx.create_dav_element("allprop"))).await?;
+                let empty_allprop = xml.create_dav_element("allprop");
+                xml.q.write_event_async(Event::Empty(empty_allprop)).await?;
                 if let Some(include) = maybe_include {
-                    include.write(xml, ctx.child()).await?;
+                    include.qwrite(xml).await?;
                 }
             },
-            Self::Prop(propname) => propname.write(xml, ctx.child()).await?,
+            Self::Prop(propname) => propname.qwrite(xml).await?,
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 /// PROPPATCH REQUEST
-impl<C: Context> QuickWritable<C> for PropertyUpdate<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("propertyupdate");
+impl<E: Extension> QWrite for PropertyUpdate<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("propertyupdate");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         for update in self.0.iter() {
-            update.write(xml, ctx.child()).await?;
+            update.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 
 /// PROPFIND RESPONSE, PROPPATCH RESPONSE, COPY RESPONSE, MOVE RESPONSE
 /// DELETE RESPONSE, 
-impl<C: Context> QuickWritable<C> for Multistatus<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("multistatus");
+impl<E: Extension> QWrite for Multistatus<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("multistatus");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         for response in self.responses.iter() {
-            response.write(xml, ctx.child()).await?;
+            response.qwrite(xml).await?;
         }
         if let Some(description) = &self.responsedescription {
-            description.write(xml, ctx.child()).await?;
+            description.qwrite(xml).await?;
         }
 
-        xml.write_event_async(Event::End(end)).await?;
+        xml.q.write_event_async(Event::End(end)).await?;
         Ok(())
     }
 }
 
 /// LOCK REQUEST
-impl<C: Context> QuickWritable<C> for LockInfo {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("lockinfo");
+impl QWrite for LockInfo {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("lockinfo");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.lockscope.write(xml, ctx.child()).await?;
-        self.locktype.write(xml, ctx.child()).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.lockscope.qwrite(xml).await?;
+        self.locktype.qwrite(xml).await?;
         if let Some(owner) = &self.owner {
-            owner.write(xml, ctx.child()).await?;
+            owner.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 /// SOME LOCK RESPONSES
-impl<C: Context> QuickWritable<C> for PropValue<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("prop");
+impl<E: Extension> QWrite for PropValue<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("prop");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         for propval in &self.0 {
-            propval.write(xml, ctx.child()).await?;
+            propval.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 // --- XML inner elements
-impl<C: Context> QuickWritable<C> for PropertyUpdateItem<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for PropertyUpdateItem<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         match self {
-            Self::Set(set) => set.write(xml, ctx).await,
-            Self::Remove(rm) => rm.write(xml, ctx).await,
+            Self::Set(set) => set.qwrite(xml).await,
+            Self::Remove(rm) => rm.qwrite(xml).await,
         }
     }
 }
 
-impl<C: Context> QuickWritable<C> for Set<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("set");
+impl<E: Extension> QWrite for Set<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("set");
         let end = start.to_end();
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.0.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.0.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Remove<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("remove");
+impl<E: Extension> QWrite for Remove<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("remove");
         let end = start.to_end();
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.0.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.0.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 
-impl<C: Context> QuickWritable<C> for AnyProp<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for AnyProp<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         match self {
-            Self::Name(propname) => propname.write(xml, ctx).await,
-            Self::Value(propval) => propval.write(xml, ctx).await,
+            Self::Name(propname) => propname.qwrite(xml).await,
+            Self::Value(propval) => propval.qwrite(xml).await,
         }
     }
 }
 
-impl<C: Context> QuickWritable<C> for PropName<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("prop");
+impl<E: Extension> QWrite for PropName<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("prop");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         for propname in &self.0 {
-            propname.write(xml, ctx.child()).await?;
+            propname.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
 
-impl<C: Context> QuickWritable<C> for Href {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("href");
+impl QWrite for Href {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("href");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        xml.write_event_async(Event::Text(BytesText::new(&self.0))).await?;
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Text(BytesText::new(&self.0))).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Response<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("response");
+impl<E: Extension> QWrite for Response<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("response");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.href.write(xml, ctx.child()).await?; 
-        self.status_or_propstat.write(xml, ctx.child()).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.href.qwrite(xml).await?; 
+        self.status_or_propstat.qwrite(xml).await?;
         if let Some(error) = &self.error {
-            error.write(xml, ctx.child()).await?;
+            error.qwrite(xml).await?;
         }
         if let Some(responsedescription) = &self.responsedescription {
-            responsedescription.write(xml, ctx.child()).await?;
+            responsedescription.qwrite(xml).await?;
         }
         if let Some(location) = &self.location {
-            location.write(xml, ctx.child()).await?;
+            location.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for StatusOrPropstat<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for StatusOrPropstat<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         match self {
-            Self::Status(status) => status.write(xml, ctx.child()).await,
+            Self::Status(status) => status.qwrite(xml).await,
             Self::PropStat(propstat_list) => {
                 for propstat in propstat_list.iter() {
-                    propstat.write(xml, ctx.child()).await?;
+                    propstat.qwrite(xml).await?;
                 }
-
                 Ok(())
             }
         }
     }
 }
 
-impl<C: Context> QuickWritable<C> for Status {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("status");
+impl QWrite for Status {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("status");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
 
         let txt = format!("HTTP/1.1 {} {}", self.0.as_str(), self.0.canonical_reason().unwrap_or("No reason"));
-        xml.write_event_async(Event::Text(BytesText::new(&txt))).await?;
+        xml.q.write_event_async(Event::Text(BytesText::new(&txt))).await?;
 
-        xml.write_event_async(Event::End(end)).await?;
+        xml.q.write_event_async(Event::End(end)).await?;
 
         Ok(())
     }
 }
 
-impl<C: Context> QuickWritable<C> for ResponseDescription {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("responsedescription");
+impl QWrite for ResponseDescription {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("responsedescription");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        xml.write_event_async(Event::Text(BytesText::new(&self.0))).await?;
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Text(BytesText::new(&self.0))).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Location {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("location");
+impl QWrite for Location {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("location");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.0.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.0.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for PropStat<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("propstat");
+impl<E: Extension> QWrite for PropStat<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("propstat");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.prop.write(xml, ctx.child()).await?;
-        self.status.write(xml, ctx.child()).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.prop.qwrite(xml).await?;
+        self.status.qwrite(xml).await?;
         if let Some(error) = &self.error {
-            error.write(xml, ctx.child()).await?;
+            error.qwrite(xml).await?;
         }
         if let Some(description) = &self.responsedescription {
-            description.write(xml, ctx.child()).await?;
+            description.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await?;
+        xml.q.write_event_async(Event::End(end)).await?;
 
         Ok(())
     }
 }
 
-impl<C: Context> QuickWritable<C> for Property<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for Property<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         use Property::*;
         match self {
             CreationDate(date) => {
                 // <D:creationdate>1997-12-01T17:42:21-08:00</D:creationdate>
-                let start = ctx.create_dav_element("creationdate");
+                let start = xml.create_dav_element("creationdate");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(&date.to_rfc3339()))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(&date.to_rfc3339()))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             DisplayName(name) => {
                 // <D:displayname>Example collection</D:displayname>
-                let start = ctx.create_dav_element("displayname");
+                let start = xml.create_dav_element("displayname");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(name))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(name))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             GetContentLanguage(lang) => {
-                let start = ctx.create_dav_element("getcontentlanguage");
+                let start = xml.create_dav_element("getcontentlanguage");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(lang))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(lang))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             GetContentLength(len) => {
                 // <D:getcontentlength>4525</D:getcontentlength>
-                let start = ctx.create_dav_element("getcontentlength");
+                let start = xml.create_dav_element("getcontentlength");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(&len.to_string()))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(&len.to_string()))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             GetContentType(ct) => {
                 // <D:getcontenttype>text/html</D:getcontenttype>
-                let start = ctx.create_dav_element("getcontenttype");
+                let start = xml.create_dav_element("getcontenttype");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(&ct))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(&ct))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             GetEtag(et) => {
                 // <D:getetag>"zzyzx"</D:getetag>
-                let start = ctx.create_dav_element("getetag");
+                let start = xml.create_dav_element("getetag");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(et))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(et))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             GetLastModified(date) => {
                 // <D:getlastmodified>Mon, 12 Jan 1998 09:25:56 GMT</D:getlastmodified>
-                let start = ctx.create_dav_element("getlastmodified");
+                let start = xml.create_dav_element("getlastmodified");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
-                xml.write_event_async(Event::Text(BytesText::new(&date.to_rfc2822()))).await?;
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Text(BytesText::new(&date.to_rfc2822()))).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             LockDiscovery(many_locks) => {
                 // <D:lockdiscovery><D:activelock> ... </D:activelock></D:lockdiscovery>
-                let start = ctx.create_dav_element("lockdiscovery");
+                let start = xml.create_dav_element("lockdiscovery");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
                 for lock in many_locks.iter() {
-                    lock.write(xml, ctx.child()).await?;
+                    lock.qwrite(xml).await?;
                 }
-                xml.write_event_async(Event::End(end)).await?;
+                xml.q.write_event_async(Event::End(end)).await?;
             },
             ResourceType(many_types) => {
                 // <D:resourcetype><D:collection/></D:resourcetype>
@@ -397,16 +346,16 @@ impl<C: Context> QuickWritable<C> for Property<C> {
                 //   <f:search-results xmlns:f="http://www.example.com/ns"/>
                 // </x:resourcetype>
     
-                let start = ctx.create_dav_element("resourcetype");
+                let start = xml.create_dav_element("resourcetype");
                 if many_types.is_empty() {
-                    xml.write_event_async(Event::Empty(start)).await?;
+                    xml.q.write_event_async(Event::Empty(start)).await?;
                 } else {
                     let end = start.to_end();
-                    xml.write_event_async(Event::Start(start.clone())).await?;
+                    xml.q.write_event_async(Event::Start(start.clone())).await?;
                     for restype in many_types.iter() {
-                        restype.write(xml, ctx.child()).await?;
+                        restype.qwrite(xml).await?;
                     }
-                    xml.write_event_async(Event::End(end)).await?;
+                    xml.q.write_event_async(Event::End(end)).await?;
                 }
             },
             SupportedLock(many_entries) => {
@@ -414,52 +363,56 @@ impl<C: Context> QuickWritable<C> for Property<C> {
 
                 //  <D:supportedlock> <D:lockentry> ... </D:lockentry> </D:supportedlock>
 
-                let start = ctx.create_dav_element("supportedlock");
+                let start = xml.create_dav_element("supportedlock");
                 if many_entries.is_empty() {
-                    xml.write_event_async(Event::Empty(start)).await?;
+                    xml.q.write_event_async(Event::Empty(start)).await?;
                 } else {
                     let end = start.to_end();
-                    xml.write_event_async(Event::Start(start.clone())).await?;
+                    xml.q.write_event_async(Event::Start(start.clone())).await?;
                     for entry in many_entries.iter() {
-                        entry.write(xml, ctx.child()).await?;
+                        entry.qwrite(xml).await?;
                     }
-                    xml.write_event_async(Event::End(end)).await?;
+                    xml.q.write_event_async(Event::End(end)).await?;
                 }
             },
-            Extension(inner) => {
-                ctx.hook_property(inner, xml).await?;
-            },
+            Extension(inner) => inner.qwrite(xml).await?,
         };
         Ok(())
     }
 }
 
-impl<C: Context> QuickWritable<C> for ResourceType<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for ResourceType<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         match self {
-            Self::Collection => xml.write_event_async(Event::Empty(ctx.create_dav_element("collection"))).await,
-            Self::Extension(inner) => ctx.hook_resourcetype(inner, xml).await,
+            Self::Collection => {
+                let empty_collection = xml.create_dav_element("collection");
+                xml.q.write_event_async(Event::Empty(empty_collection)).await
+            },
+            Self::Extension(inner) => inner.qwrite(xml).await,
         }
     }
 }
 
-impl<C: Context> QuickWritable<C> for Include<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("include");
+impl<E: Extension> QWrite for Include<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("include");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;  
+        xml.q.write_event_async(Event::Start(start.clone())).await?;  
         for prop in self.0.iter() {
-            prop.write(xml, ctx.child()).await?;
+            prop.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for PropertyRequest<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for PropertyRequest<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         use PropertyRequest::*;
-        let mut atom = async |c| xml.write_event_async(Event::Empty(ctx.create_dav_element(c))).await;
+        let mut atom = async |c| {
+            let empty_tag = xml.create_dav_element(c);
+            xml.q.write_event_async(Event::Empty(empty_tag)).await
+        };
 
         match self {
             CreationDate => atom("creationdate").await,
@@ -472,13 +425,13 @@ impl<C: Context> QuickWritable<C> for PropertyRequest<C> {
             LockDiscovery => atom("lockdiscovery").await,
             ResourceType => atom("resourcetype").await,
             SupportedLock => atom("supportedlock").await,
-            Extension(inner) => ctx.hook_propertyrequest(inner, xml).await,
+            Extension(inner) => inner.qwrite(xml).await,
         }
     }
 }
 
-impl<C: Context> QuickWritable<C> for ActiveLock {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl QWrite for ActiveLock {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
         // <D:activelock>
         //   <D:locktype><D:write/></D:locktype>
         //   <D:lockscope><D:exclusive/></D:lockscope>
@@ -494,192 +447,193 @@ impl<C: Context> QuickWritable<C> for ActiveLock {
         //     <D:href>http://example.com/workspace/webdav/proposal.doc</D:href>
         //   </D:lockroot>
         // </D:activelock>
-        let start = ctx.create_dav_element("activelock");
+        let start = xml.create_dav_element("activelock");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.locktype.write(xml, ctx.child()).await?;
-        self.lockscope.write(xml, ctx.child()).await?;
-        self.depth.write(xml, ctx.child()).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.locktype.qwrite(xml).await?;
+        self.lockscope.qwrite(xml).await?;
+        self.depth.qwrite(xml).await?;
         if let Some(owner) = &self.owner {
-            owner.write(xml, ctx.child()).await?;
+            owner.qwrite(xml).await?;
         }
         if let Some(timeout) = &self.timeout {
-            timeout.write(xml, ctx.child()).await?;
+            timeout.qwrite(xml).await?;
         }
         if let Some(locktoken) = &self.locktoken {
-            locktoken.write(xml, ctx.child()).await?;
+            locktoken.qwrite(xml).await?;
         }
-        self.lockroot.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        self.lockroot.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for LockType {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("locktype");
+impl QWrite for LockType {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("locktype");
         let end = start.to_end();
-        let ctx = ctx.child();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
-            Self::Write => xml.write_event_async(Event::Empty(ctx.create_dav_element("write"))).await?,
+            Self::Write => {
+                let empty_write = xml.create_dav_element("write");
+                xml.q.write_event_async(Event::Empty(empty_write)).await?
+            },
         }; 
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for LockScope {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("lockscope");
+impl QWrite for LockScope {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("lockscope");
         let end = start.to_end();
-        let ctx = ctx.child();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
-            Self::Exclusive => xml.write_event_async(Event::Empty(ctx.create_dav_element("exclusive"))).await?,
-            Self::Shared => xml.write_event_async(Event::Empty(ctx.create_dav_element("shared"))).await?,
+            Self::Exclusive => {
+                let empty_tag = xml.create_dav_element("exclusive");
+                xml.q.write_event_async(Event::Empty(empty_tag)).await?
+            },
+            Self::Shared => {
+                let empty_tag = xml.create_dav_element("shared");
+                xml.q.write_event_async(Event::Empty(empty_tag)).await?
+            },
         }; 
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Owner {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("owner");
+impl QWrite for Owner {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("owner");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
-            Self::Txt(txt) => xml.write_event_async(Event::Text(BytesText::new(&txt))).await?,
-            Self::Href(href) => href.write(xml, ctx.child()).await?,
+            Self::Txt(txt) => xml.q.write_event_async(Event::Text(BytesText::new(&txt))).await?,
+            Self::Href(href) => href.qwrite(xml).await?,
         }
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Depth {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("depth");
+impl QWrite for Depth {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("depth");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
-            Self::Zero => xml.write_event_async(Event::Text(BytesText::new("0"))).await?,
-            Self::One => xml.write_event_async(Event::Text(BytesText::new("1"))).await?,
-            Self::Infinity => xml.write_event_async(Event::Text(BytesText::new("infinity"))).await?,
+            Self::Zero => xml.q.write_event_async(Event::Text(BytesText::new("0"))).await?,
+            Self::One => xml.q.write_event_async(Event::Text(BytesText::new("1"))).await?,
+            Self::Infinity => xml.q.write_event_async(Event::Text(BytesText::new("infinity"))).await?,
         };
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Timeout {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("timeout");
+impl QWrite for Timeout {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("timeout");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         match self {
             Self::Seconds(count) => {
                 let txt = format!("Second-{}", count);
-                xml.write_event_async(Event::Text(BytesText::new(&txt))).await?
+                xml.q.write_event_async(Event::Text(BytesText::new(&txt))).await?
             },
-            Self::Infinite => xml.write_event_async(Event::Text(BytesText::new("Infinite"))).await?
+            Self::Infinite => xml.q.write_event_async(Event::Text(BytesText::new("Infinite"))).await?
         };
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for LockToken {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("locktoken");
+impl QWrite for LockToken {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("locktoken");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.0.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.0.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for LockRoot {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("lockroot");
+impl QWrite for LockRoot {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("lockroot");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.0.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.0.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for LockEntry {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("lockentry");
+impl QWrite for LockEntry {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("lockentry");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
-        self.lockscope.write(xml, ctx.child()).await?;
-        self.locktype.write(xml, ctx.child()).await?;
-        xml.write_event_async(Event::End(end)).await
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
+        self.lockscope.qwrite(xml).await?;
+        self.locktype.qwrite(xml).await?;
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Error<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
-        let start = ctx.create_dav_element("error");
+impl<E: Extension> QWrite for Error<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let start = xml.create_dav_element("error");
         let end = start.to_end();
 
-        xml.write_event_async(Event::Start(start.clone())).await?;
+        xml.q.write_event_async(Event::Start(start.clone())).await?;
         for violation in &self.0 {
-            violation.write(xml, ctx.child()).await?;
+            violation.qwrite(xml).await?;
         }
-        xml.write_event_async(Event::End(end)).await?;
-
-        Ok(())
+        xml.q.write_event_async(Event::End(end)).await
     }
 }
 
-impl<C: Context> QuickWritable<C> for Violation<C> {
-    async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+impl<E: Extension> QWrite for Violation<E> {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), QError> {
+        let mut atom = async |c| {
+            let empty_tag = xml.create_dav_element(c);
+            xml.q.write_event_async(Event::Empty(empty_tag)).await
+        };
+
         match self {
-            Violation::LockTokenMatchesRequestUri => xml.write_event_async(Event::Empty(ctx.create_dav_element("lock-token-matches-request-uri"))).await?, 
-            Violation::LockTokenSubmitted(hrefs) if hrefs.is_empty() => {
-                xml.write_event_async(Event::Empty(ctx.create_dav_element("lock-token-submitted"))).await?
-            },
+            Violation::LockTokenMatchesRequestUri => atom("lock-token-matches-request-uri").await, 
+            Violation::LockTokenSubmitted(hrefs) if hrefs.is_empty() => atom("lock-token-submitted").await,
             Violation::LockTokenSubmitted(hrefs) => {
-                let start = ctx.create_dav_element("lock-token-submitted");
+                let start = xml.create_dav_element("lock-token-submitted");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
                 for href in hrefs {
-                    href.write(xml, ctx.child()).await?;
+                    href.qwrite(xml).await?;
                 }
-                xml.write_event_async(Event::End(end)).await?;
-            },
-            Violation::NoConflictingLock(hrefs) if hrefs.is_empty() => {
-                xml.write_event_async(Event::Empty(ctx.create_dav_element("no-conflicting-lock"))).await?
+                xml.q.write_event_async(Event::End(end)).await
             },
+            Violation::NoConflictingLock(hrefs) if hrefs.is_empty() => atom("no-conflicting-lock").await,
             Violation::NoConflictingLock(hrefs) => {
-                let start = ctx.create_dav_element("no-conflicting-lock");
+                let start = xml.create_dav_element("no-conflicting-lock");
                 let end = start.to_end();
 
-                xml.write_event_async(Event::Start(start.clone())).await?;
+                xml.q.write_event_async(Event::Start(start.clone())).await?;
                 for href in hrefs {
-                    href.write(xml, ctx.child()).await?;
+                    href.qwrite(xml).await?;
                 }
-                xml.write_event_async(Event::End(end)).await?;
-            },
-            Violation::NoExternalEntities => xml.write_event_async(Event::Empty(ctx.create_dav_element("no-external-entities"))).await?,
-            Violation::PreservedLiveProperties => xml.write_event_async(Event::Empty(ctx.create_dav_element("preserved-live-properties"))).await?,
-            Violation::PropfindFiniteDepth => xml.write_event_async(Event::Empty(ctx.create_dav_element("propfind-finite-depth"))).await?,
-            Violation::CannotModifyProtectedProperty => xml.write_event_async(Event::Empty(ctx.create_dav_element("cannot-modify-protected-property"))).await?,
-            Violation::Extension(inner) => {
-                ctx.hook_error(inner, xml).await?;
+                xml.q.write_event_async(Event::End(end)).await
             },
-        };
-        Ok(())
+            Violation::NoExternalEntities => atom("no-external-entities").await,
+            Violation::PreservedLiveProperties => atom("preserved-live-properties").await,
+            Violation::PropfindFiniteDepth => atom("propfind-finite-depth").await,
+            Violation::CannotModifyProtectedProperty => atom("cannot-modify-protected-property").await,
+            Violation::Extension(inner) => inner.qwrite(xml).await,
+        }
     }
 }
 
diff --git a/src/dav/error.rs b/src/dav/error.rs
new file mode 100644
index 0000000..1db2895
--- /dev/null
+++ b/src/dav/error.rs
@@ -0,0 +1,20 @@
+use quick_xml::events::attributes::AttrError;
+
+#[derive(Debug)]
+pub enum ParsingError {
+    NamespacePrefixAlreadyUsed,
+    WrongToken,
+    TagNotFound,
+    QuickXml(quick_xml::Error), 
+    Eof
+}
+impl From<AttrError> for ParsingError {
+    fn from(value: AttrError) -> Self {
+        Self::QuickXml(value.into())
+    }
+}
+impl From<quick_xml::Error> for ParsingError {
+    fn from(value: quick_xml::Error) -> Self {
+        Self::QuickXml(value)
+    }
+}
diff --git a/src/dav/mod.rs b/src/dav/mod.rs
index 835544b..abc46e7 100644
--- a/src/dav/mod.rs
+++ b/src/dav/mod.rs
@@ -1,3 +1,5 @@
+mod error;
+mod xml;
 mod types;
 mod caltypes;
 mod acltypes;
@@ -5,6 +7,7 @@ mod versioningtypes;
 mod encoder;
 mod calencoder;
 mod decoder;
+mod realization;
 
 use std::net::SocketAddr;
 
diff --git a/src/dav/realization.rs b/src/dav/realization.rs
new file mode 100644
index 0000000..22c9cfc
--- /dev/null
+++ b/src/dav/realization.rs
@@ -0,0 +1,41 @@
+use super::types as dav;
+use super::caltypes as cal;
+use super::xml;
+use super::error;
+
+#[derive(Debug, PartialEq)]
+pub struct Disabled(());
+impl xml::QRead<Disabled> for Disabled {
+    async fn qread(&self, xml: &mut xml::Reader<impl xml::IRead>) -> Result<Option<Self>, error::ParsingError> {
+        unreachable!();
+    }
+}
+impl xml::QWrite for Disabled {
+    async fn qwrite(&self, xml: &mut xml::Writer<impl xml::IWrite>) -> Result<(), quick_xml::Error> {
+        unreachable!();
+    }
+}
+
+/// The base WebDAV 
+///
+/// Any extension is kooh is disabled through an object we can't build
+/// due to a private inner element.
+pub struct Core {}
+impl dav::Extension for Core {
+    type Error = Disabled;
+    type Property = Disabled;
+    type PropertyRequest = Disabled;
+    type ResourceType = Disabled;
+}
+
+/*
+// WebDAV with the base Calendar implementation (RFC4791)
+pub struct CalendarMin {}
+impl dav::Extension for CalendarMin
+{
+    type Error = cal::Violation;
+    type Property = cal::Property;
+    type PropertyRequest = cal::PropertyRequest;
+    type ResourceType = cal::ResourceType;
+}
+*/
diff --git a/src/dav/types.rs b/src/dav/types.rs
index a1b1c7f..f2eae3a 100644
--- a/src/dav/types.rs
+++ b/src/dav/types.rs
@@ -1,28 +1,20 @@
 #![allow(dead_code)]
+use std::fmt::Debug;
 
 use chrono::{DateTime,FixedOffset};
+use super::xml;
+use super::error;
 
-/// Extension utilities
-pub struct Disabled(());
+/// It's how we implement a DAV extension
+/// (That's the dark magic part...)
+pub trait ExtensionItem<T> = xml::QRead<T> + xml::QWrite + Debug + PartialEq;
 pub trait Extension {
-    type Error;
-    type Property;
-    type PropertyRequest;
-    type ResourceType;
+    type Error: ExtensionItem<Self::Error>;
+    type Property: ExtensionItem<Self::Property>;
+    type PropertyRequest: ExtensionItem<Self::PropertyRequest>;
+    type ResourceType: ExtensionItem<Self::ResourceType>;
 }
 
-/// No extension
-pub struct NoExtension {
-    pub root: bool
-}
-impl Extension for NoExtension {
-    type Error = Disabled;
-    type Property = Disabled;
-    type PropertyRequest = Disabled;
-    type ResourceType = Disabled;
-}
-
-
 /// 14.1.  activelock XML Element
 ///
 /// Name:   activelock
@@ -30,6 +22,7 @@ impl Extension for NoExtension {
 /// Purpose:   Describes a lock on a resource.
 /// <!ELEMENT activelock (lockscope, locktype, depth, owner?, timeout?,
 ///           locktoken?, lockroot)>
+#[derive(Debug, PartialEq)]
 pub struct ActiveLock {
     pub lockscope: LockScope,
     pub locktype: LockType,
@@ -50,6 +43,7 @@ pub struct ActiveLock {
 /// elements.
 ///
 /// <!ELEMENT collection EMPTY >
+#[derive(Debug, PartialEq)]
 pub struct Collection{}
 
 /// 14.4 depth XML Element
@@ -62,6 +56,7 @@ pub struct Collection{}
 /// Value:   "0" | "1" | "infinity"
 ///
 /// <!ELEMENT depth (#PCDATA) >
+#[derive(Debug, PartialEq)]
 pub enum Depth {
     Zero,
     One,
@@ -84,8 +79,10 @@ pub enum Depth {
 ///   postcondition code.  Unrecognized elements MUST be ignored.
 ///
 /// <!ELEMENT error ANY >
-pub struct Error<T: Extension>(pub Vec<Violation<T>>);
-pub enum Violation<T: Extension> {
+#[derive(Debug, PartialEq)]
+pub struct Error<E: Extension>(pub Vec<Violation<E>>);
+#[derive(Debug, PartialEq)]
+pub enum Violation<E: Extension> {
     /// Name:  lock-token-matches-request-uri
     ///
     /// Use with:  409 Conflict
@@ -169,7 +166,7 @@ pub enum Violation<T: Extension> {
     CannotModifyProtectedProperty,
 
     /// Specific errors
-    Extension(T::Error),
+    Extension(E::Error),
 }
 
 /// 14.6.  exclusive XML Element
@@ -179,6 +176,7 @@ pub enum Violation<T: Extension> {
 /// Purpose:   Specifies an exclusive lock.
 /// 
 /// <!ELEMENT exclusive EMPTY >
+#[derive(Debug, PartialEq)]
 pub struct Exclusive {}
 
 /// 14.7.  href XML Element
@@ -194,6 +192,7 @@ pub struct Exclusive {}
 /// Value:   Simple-ref
 ///
 /// <!ELEMENT href (#PCDATA)>
+#[derive(Debug, PartialEq)]
 pub struct Href(pub String);
 
 
@@ -209,7 +208,8 @@ pub struct Href(pub String);
 /// standards.  This element MUST NOT contain text or mixed content.
 ///
 /// <!ELEMENT include ANY >
-pub struct Include<T: Extension>(pub Vec<PropertyRequest<T>>);
+#[derive(Debug, PartialEq)]
+pub struct Include<E: Extension>(pub Vec<PropertyRequest<E>>);
 
 /// 14.9.  location XML Element
 ///
@@ -225,6 +225,7 @@ pub struct Include<T: Extension>(pub Vec<PropertyRequest<T>>);
 /// that would be used in a Location header.
 ///
 /// <!ELEMENT location (href)>
+#[derive(Debug, PartialEq)]
 pub struct Location(pub Href);
 
 /// 14.10.  lockentry XML Element
@@ -235,6 +236,7 @@ pub struct Location(pub Href);
 /// resource.
 ///
 /// <!ELEMENT lockentry (lockscope, locktype) >
+#[derive(Debug, PartialEq)]
 pub struct LockEntry {
     pub lockscope: LockScope,
     pub locktype: LockType,
@@ -248,6 +250,7 @@ pub struct LockEntry {
 /// specify the type of lock the client wishes to have created.
 ///
 /// <!ELEMENT lockinfo (lockscope, locktype, owner?)  >
+#[derive(Debug, PartialEq)]
 pub struct LockInfo {
     pub lockscope: LockScope,
     pub locktype: LockType,
@@ -266,6 +269,7 @@ pub struct LockInfo {
 /// values and the response to LOCK requests.
 ///
 /// <!ELEMENT lockroot (href) >
+#[derive(Debug, PartialEq)]
 pub struct LockRoot(pub Href);
 
 /// 14.13.  lockscope XML Element
@@ -275,6 +279,7 @@ pub struct LockRoot(pub Href);
 /// Purpose:   Specifies whether a lock is an exclusive lock, or a shared
 /// lock.
 /// <!ELEMENT lockscope (exclusive | shared) >
+#[derive(Debug, PartialEq)]
 pub enum LockScope {
     Exclusive,
     Shared
@@ -290,6 +295,7 @@ pub enum LockScope {
 ///    refers to the lock.
 ///
 /// <!ELEMENT locktoken (href) >
+#[derive(Debug, PartialEq)]
 pub struct LockToken(pub Href);
 
 /// 14.15.  locktype XML Element
@@ -300,6 +306,7 @@ pub struct LockToken(pub Href);
 /// specification only defines one lock type, the write lock.
 ///
 /// <!ELEMENT locktype (write) >
+#[derive(Debug, PartialEq)]
 pub enum LockType {
     /// 14.30.  write XML Element
     ///
@@ -325,8 +332,9 @@ pub enum LockType {
 /// response descriptions contained within the responses.
 ///
 /// <!ELEMENT multistatus (response*, responsedescription?)  >
-pub struct Multistatus<T: Extension> {
-    pub responses: Vec<Response<T>>,
+#[derive(Debug, PartialEq)]
+pub struct Multistatus<E: Extension> {
+    pub responses: Vec<Response<E>>,
     pub responsedescription: Option<ResponseDescription>,
 }
 
@@ -354,6 +362,7 @@ pub struct Multistatus<T: Extension> {
 ///
 /// <!ELEMENT owner ANY >
 //@FIXME might need support for an extension
+#[derive(Debug, PartialEq)]
 pub enum Owner {
     Txt(String),
     Href(Href),
@@ -373,12 +382,17 @@ pub enum Owner {
 /// text or mixed content.
 ///
 /// <!ELEMENT prop ANY >
-pub enum AnyProp<T: Extension> {
-    Name(PropName<T>),
-    Value(PropValue<T>),
+#[derive(Debug, PartialEq)]
+pub enum AnyProp<E: Extension> {
+    Name(PropName<E>),
+    Value(PropValue<E>),
 }
-pub struct PropName<T: Extension>(pub Vec<PropertyRequest<T>>);
-pub struct PropValue<T: Extension>(pub Vec<Property<T>>);
+
+#[derive(Debug, PartialEq)]
+pub struct PropName<E: Extension>(pub Vec<PropertyRequest<E>>);
+
+#[derive(Debug, PartialEq)]
+pub struct PropValue<E: Extension>(pub Vec<Property<E>>);
 
 /// 14.19.  propertyupdate XML Element
 ///
@@ -390,10 +404,13 @@ pub struct PropValue<T: Extension>(pub Vec<Property<T>>);
 /// required to modify the properties on the resource.
 ///
 /// <!ELEMENT propertyupdate (remove | set)+ >
-pub struct PropertyUpdate<T: Extension>(pub Vec<PropertyUpdateItem<T>>);
-pub enum PropertyUpdateItem<T: Extension> {
-    Remove(Remove<T>),
-    Set(Set<T>),
+#[derive(Debug, PartialEq)]
+pub struct PropertyUpdate<E: Extension>(pub Vec<PropertyUpdateItem<E>>);
+
+#[derive(Debug, PartialEq)]
+pub enum PropertyUpdateItem<E: Extension> {
+    Remove(Remove<E>),
+    Set(Set<E>),
 }
 
 /// 14.2 allprop XML Element
@@ -430,10 +447,11 @@ pub enum PropertyUpdateItem<T: Extension> {
 /// values.
 ///
 /// <!ELEMENT propfind ( propname | (allprop, include?) | prop ) >
-pub enum PropFind<T: Extension> {
+#[derive(Debug, PartialEq)]
+pub enum PropFind<E: Extension> {
     PropName,
-    AllProp(Option<Include<T>>),
-    Prop(PropName<T>),
+    AllProp(Option<Include<E>>),
+    Prop(PropName<E>),
 }
 
 /// 14.22 propstat XML Element
@@ -451,10 +469,11 @@ pub enum PropFind<T: Extension> {
 /// the properties named in 'prop'.
 ///
 /// <!ELEMENT propstat (prop, status, error?, responsedescription?) >
-pub struct PropStat<T: Extension> {
-    pub prop: AnyProp<T>,
+#[derive(Debug, PartialEq)]
+pub struct PropStat<E: Extension> {
+    pub prop: AnyProp<E>,
     pub status: Status,
-    pub error: Option<Error<T>>,
+    pub error: Option<Error<E>>,
     pub responsedescription: Option<ResponseDescription>,
 }
 
@@ -471,7 +490,8 @@ pub struct PropStat<T: Extension> {
 /// the names of properties to be removed are required.
 ///
 /// <!ELEMENT remove (prop) >
-pub struct Remove<T: Extension>(pub PropName<T>);
+#[derive(Debug, PartialEq)]
+pub struct Remove<E: Extension>(pub PropName<E>);
 
 /// 14.24.  response XML Element
 ///
@@ -495,14 +515,17 @@ pub struct Remove<T: Extension>(pub PropName<T>);
 ///
 /// <!ELEMENT response (href, ((href*, status)|(propstat+)),
 ///                     error?, responsedescription? , location?) >
-pub enum StatusOrPropstat<T: Extension> {
+#[derive(Debug, PartialEq)]
+pub enum StatusOrPropstat<E: Extension> {
     Status(Status),
-    PropStat(Vec<PropStat<T>>),
+    PropStat(Vec<PropStat<E>>),
 }
-pub struct Response<T: Extension> {
+
+#[derive(Debug, PartialEq)]
+pub struct Response<E: Extension> {
     pub href: Href, // It's wrong according to the spec, but I don't understand why there is an href*
-    pub status_or_propstat: StatusOrPropstat<T>,
-    pub error: Option<Error<T>>,
+    pub status_or_propstat: StatusOrPropstat<E>,
+    pub error: Option<Error<E>>,
     pub responsedescription: Option<ResponseDescription>,
     pub location: Option<Location>,
 }
@@ -518,6 +541,7 @@ pub struct Response<T: Extension> {
 /// user.
 ///
 /// <!ELEMENT responsedescription (#PCDATA) >
+#[derive(Debug, PartialEq)]
 pub struct ResponseDescription(pub String);
 
 /// 14.26.  set XML Element
@@ -536,7 +560,8 @@ pub struct ResponseDescription(pub String);
 /// property, and MUST be subsequently retrievable using PROPFIND.
 ///
 /// <!ELEMENT set (prop) >
-pub struct Set<T: Extension>(pub PropValue<T>);
+#[derive(Debug, PartialEq)]
+pub struct Set<E: Extension>(pub PropValue<E>);
 
 /// 14.27.  shared XML Element
 ///
@@ -546,6 +571,7 @@ pub struct Set<T: Extension>(pub PropValue<T>);
 ///
 ///
 /// <!ELEMENT shared EMPTY >
+#[derive(Debug, PartialEq)]
 pub struct Shared {}
 
 
@@ -559,6 +585,7 @@ pub struct Shared {}
 /// 
 /// <!ELEMENT status (#PCDATA) >
 //@FIXME: Better typing is possible with an enum for example
+#[derive(Debug, PartialEq)]
 pub struct Status(pub http::status::StatusCode);
 
 /// 14.29.  timeout XML Element
@@ -586,6 +613,7 @@ pub struct Status(pub http::status::StatusCode);
 /// elapse between granting of the lock at the server, and the automatic
 /// removal of the lock.  The timeout value for TimeType "Second" MUST
 /// NOT be greater than 2^32-1.
+#[derive(Debug, PartialEq)]
 pub enum Timeout {
     Seconds(u32),
     Infinite,
@@ -619,7 +647,8 @@ pub enum Timeout {
 /// the header value could include LWS as defined in [RFC2616], Section
 /// 4.2.  Server implementors SHOULD strip LWS from these values before
 /// using as WebDAV property values.
-pub enum PropertyRequest<T: Extension> {
+#[derive(Debug, PartialEq)]
+pub enum PropertyRequest<E: Extension> {
     CreationDate,
     DisplayName,
     GetContentLanguage,
@@ -630,9 +659,11 @@ pub enum PropertyRequest<T: Extension> {
     LockDiscovery,
     ResourceType,
     SupportedLock,
-    Extension(T::PropertyRequest),
+    Extension(E::PropertyRequest),
 }
-pub enum Property<T: Extension> {
+
+#[derive(Debug, PartialEq)]
+pub enum Property<E: Extension> {
     /// 15.1.  creationdate Property
     ///
     /// Name:   creationdate
@@ -883,7 +914,7 @@ pub enum Property<T: Extension> {
     ///       <x:collection/>
     ///       <f:search-results xmlns:f="http://www.example.com/ns"/>
     ///   </x:resourcetype>
-    ResourceType(Vec<ResourceType<T>>),
+    ResourceType(Vec<ResourceType<E>>),
 
     /// 15.10.  supportedlock Property
     ///
@@ -911,10 +942,11 @@ pub enum Property<T: Extension> {
     SupportedLock(Vec<LockEntry>),
 
     /// Any extension
-    Extension(T::Property),
+    Extension(E::Property),
 }
 
-pub enum ResourceType<T: Extension> {
+#[derive(Debug, PartialEq)]
+pub enum ResourceType<E: Extension> {
     Collection,
-    Extension(T::ResourceType),
+    Extension(E::ResourceType),
 }
diff --git a/src/dav/xml.rs b/src/dav/xml.rs
new file mode 100644
index 0000000..777f99e
--- /dev/null
+++ b/src/dav/xml.rs
@@ -0,0 +1,128 @@
+use std::collections::HashMap;
+use tokio::io::{AsyncWrite, AsyncBufRead};
+use quick_xml::events::{Event, BytesEnd, BytesStart, BytesText};
+use quick_xml::name::{Namespace, QName, PrefixDeclaration, ResolveResult, ResolveResult::*};
+use quick_xml::reader::NsReader;
+
+use super::error::ParsingError;
+
+// Async traits
+pub trait IWrite = AsyncWrite + Unpin;
+pub trait IRead = AsyncBufRead + Unpin + 'static;
+
+// Serialization/Deserialization traits
+pub trait QWrite {
+    async fn qwrite(&self, xml: &mut Writer<impl IWrite>) -> Result<(), quick_xml::Error>; 
+}
+pub trait QRead<T> {
+    async fn qread(&self, xml: &mut Reader<impl IRead>) -> Result<Option<T>, ParsingError>;
+}
+
+/// Transform a Rust object into an XML stream of characters
+pub struct Writer<T: IWrite> {
+    pub q: quick_xml::writer::Writer<T>,
+    root: bool,
+}
+impl<T: IWrite> Writer<T> {
+    pub fn create_dav_element(&mut self, name: &str) -> BytesStart<'static> {
+        self.create_ns_element("D", name)
+    }
+    pub fn create_cal_element(&mut self, name: &str) -> BytesStart<'static> {
+        self.create_ns_element("C", name)
+    }
+
+    fn create_ns_element(&mut self, ns: &str, name: &str) -> BytesStart<'static> {
+        let mut start = BytesStart::new(format!("{}:{}", ns, name));
+        //@FIXME not what we want
+        if self.root {
+            start.push_attribute(("xmlns:D", "DAV:"));
+            start.push_attribute(("xmlns:C", "urn:ietf:params:xml:ns:caldav"));
+            self.root = false;
+        }
+        start
+    }
+}
+
+/// Transform an XML stream of characters into a Rust object
+pub struct Reader<T: IRead> {
+    evt: Event<'static>,
+    rdr: NsReader<T>,
+    buf: Vec<u8>,
+}
+impl<T: IRead> Reader<T> {
+    async fn new(mut rdr: NsReader<T>) -> Result<Self, ParsingError> {
+        let mut buf: Vec<u8> = vec![];
+        let evt = rdr.read_event_into_async(&mut buf).await?.into_owned();
+        buf.clear();
+        Ok(Self { evt, rdr, buf })
+    }
+
+    fn peek(&self) -> &Event<'static> {
+        &self.evt
+    }
+
+    /// skip tag. Can't skip end, can't skip eof.
+    async fn skip(&mut self) -> Result<Event<'static>, ParsingError> {
+        match &self.evt {
+            Event::Start(b) => {
+                let _span = self.rdr.read_to_end_into_async(b.to_end().name(), &mut self.buf).await?;
+                self.next().await
+            },
+            Event::End(_) => Err(ParsingError::WrongToken),
+            Event::Eof => Err(ParsingError::Eof),
+            _ => self.next().await,
+        }
+    }
+
+    /// read one more tag
+    async fn next(&mut self) -> Result<Event<'static>, ParsingError> {
+       let evt = self.rdr.read_event_into_async(&mut self.buf).await?.into_owned(); 
+       self.buf.clear();
+       let old_evt = std::mem::replace(&mut self.evt, evt);
+       Ok(old_evt)
+    }
+
+
+    /// check if this is the desired tag
+    fn is_tag(&self, ns: &[u8], key: &str) -> bool {
+        let qname = match self.peek() {
+            Event::Start(bs) | Event::Empty(bs) => bs.name(),
+            Event::End(be) => be.name(),
+            _ => return false,
+        };
+    
+        let (extr_ns, local) = self.rdr.resolve_element(qname);
+
+        if local.into_inner() != key.as_bytes() {
+            return false
+        }
+        
+        match extr_ns {
+            ResolveResult::Bound(v) => v.into_inner() == ns,
+            _ => false,
+        }
+    }
+
+    /// find start tag
+    async fn tag_start(&mut self, ns: &[u8], key: &str) -> Result<Event<'static>, ParsingError> {
+        loop {
+            match self.peek() {
+                Event::Start(b) if self.is_tag(ns, key) => break,
+                _ => { self.skip().await?; },
+            }
+        }
+        self.next().await
+    }
+
+    // find stop tag
+    async fn tag_stop(&mut self, ns: &[u8], key: &str) -> Result<Event<'static>, ParsingError> {
+        loop {
+            match self.peek() {
+                Event::End(b) if self.is_tag(ns, key) => break,
+                _ => { self.skip().await?; },
+            }
+        }
+        self.next().await
+    }
+}
+