@@ -648,7 +648,8 @@ impl<T: FromXml> ReadXsoState<T> {
}
Ok(Some(rxml::Event::StartElement(_, name, attrs))) => {
let source_tmp = source.as_mut();
- let ctx = xso::Context::new(source_tmp.lang_stack.current());
+ let ctx = xso::Context::empty()
+ .with_language(source_tmp.lang_stack.current());
*self = ReadXsoState::Parsing(
<Result<T, xso::error::Error> as FromXml>::from_events(
name, attrs, &ctx,
@@ -708,7 +709,7 @@ impl<T: FromXml> ReadXsoState<T> {
};
let source_tmp = source.as_mut();
- let ctx = xso::Context::new(source_tmp.lang_stack.current());
+ let ctx = xso::Context::empty().with_language(source_tmp.lang_stack.current());
match builder.feed(ev, &ctx) {
Err(err) => {
*self = ReadXsoState::Done;
@@ -150,24 +150,33 @@ pub trait AsXml {
fn as_xml_iter(&self) -> Result<Self::ItemIter<'_>, self::error::Error>;
}
-/// Additional parsing context supplied to [`FromEventsBuilder`]
-/// implementations.
+/// # Parsing context for [`FromEventsBuilder`]
+///
+/// For the most part, [`FromEventsBuilder`] implementations can work with
+/// only the information inside the [`rxml::Event`] which is delivered to
+/// them (and any information they may have stored from previous events).
+///
+/// However, there is (currently) one special case: the `xml:lang` attribute.
+/// That attribute is inherited across the entire document tree hierarchy. If
+/// the parsed element is not the top-level element, there may be an implicit
+/// value for `xml:lang`.
+#[derive(Debug)]
pub struct Context<'x> {
language: Option<&'x str>,
}
impl<'x> Context<'x> {
/// A context suitable for the beginning of the document.
+ ///
+ /// `xml:lang` is assumed to be unset.
pub fn empty() -> Self {
Self { language: None }
}
- /// Create a new context.
- ///
- /// - `language` must be the effective value of the `xml:lang` value at
- /// the end of the current event.
- pub fn new(language: Option<&'x str>) -> Self {
- Self { language }
+ /// Set the effective `xml:lang` value on the context and return it.
+ pub fn with_language(mut self, language: Option<&'x str>) -> Self {
+ self.language = language;
+ self
}
/// Return the `xml:lang` value in effect at the end of the event which
@@ -474,7 +483,11 @@ pub fn transform<T: FromXml, F: AsXml>(from: &F) -> Result<T, self::error::Error
_ => panic!("into_event_iter did not start with StartElement event!"),
};
languages.push_from_attrs(&attrs);
- let mut sink = match T::from_events(qname, attrs, &Context::new(languages.current())) {
+ let mut sink = match T::from_events(
+ qname,
+ attrs,
+ &Context::empty().with_language(languages.current()),
+ ) {
Ok(v) => v,
Err(self::error::FromEventsError::Mismatch { .. }) => {
return Err(self::error::Error::TypeMismatch)
@@ -484,7 +497,7 @@ pub fn transform<T: FromXml, F: AsXml>(from: &F) -> Result<T, self::error::Error
for event in iter {
let event = event?;
languages.handle_event(&event);
- if let Some(v) = sink.feed(event, &Context::new(languages.current()))? {
+ if let Some(v) = sink.feed(event, &Context::empty().with_language(languages.current()))? {
return Ok(v);
}
}
@@ -510,7 +523,11 @@ pub fn try_from_element<T: FromXml>(
let (qname, attrs) = minidom_compat::make_start_ev_parts(&from)?;
languages.push_from_attrs(&attrs);
- let mut sink = match T::from_events(qname, attrs, &Context::new(languages.current())) {
+ let mut sink = match T::from_events(
+ qname,
+ attrs,
+ &Context::empty().with_language(languages.current()),
+ ) {
Ok(v) => v,
Err(self::error::FromEventsError::Mismatch { .. }) => {
return Err(self::error::FromElementError::Mismatch(from))
@@ -541,7 +558,7 @@ pub fn try_from_element<T: FromXml>(
for event in iter {
let event = event?;
languages.handle_event(&event);
- if let Some(v) = sink.feed(event, &Context::new(languages.current()))? {
+ if let Some(v) = sink.feed(event, &Context::empty().with_language(languages.current()))? {
return Ok(v);
}
}
@@ -576,7 +593,11 @@ pub fn from_bytes<T: FromXml>(mut buf: &[u8]) -> Result<T, self::error::Error> {
}
};
languages.push_from_attrs(&attrs);
- let mut builder = match T::from_events(name, attrs, &Context::new(languages.current())) {
+ let mut builder = match T::from_events(
+ name,
+ attrs,
+ &Context::empty().with_language(languages.current()),
+ ) {
Ok(v) => v,
Err(self::error::FromEventsError::Mismatch { .. }) => {
return Err(self::error::Error::TypeMismatch);
@@ -590,7 +611,9 @@ pub fn from_bytes<T: FromXml>(mut buf: &[u8]) -> Result<T, self::error::Error> {
match parser.parse(&mut buf, true) {
Ok(Some(ev)) => {
languages.handle_event(&ev);
- if let Some(v) = builder.feed(ev, &Context::new(languages.current()))? {
+ if let Some(v) =
+ builder.feed(ev, &Context::empty().with_language(languages.current()))?
+ {
return Ok(v);
}
}
@@ -631,7 +654,11 @@ fn read_start_event_io(
pub fn from_reader<T: FromXml, R: io::BufRead>(r: R) -> io::Result<T> {
let mut reader = rxml::XmlLangTracker::wrap(rxml::Reader::new(r));
let (name, attrs) = read_start_event_io(&mut reader)?;
- let mut builder = match T::from_events(name, attrs, &Context::new(reader.language())) {
+ let mut builder = match T::from_events(
+ name,
+ attrs,
+ &Context::empty().with_language(reader.language()),
+ ) {
Ok(v) => v,
Err(self::error::FromEventsError::Mismatch { .. }) => {
return Err(self::error::Error::TypeMismatch)
@@ -643,7 +670,7 @@ pub fn from_reader<T: FromXml, R: io::BufRead>(r: R) -> io::Result<T> {
};
while let Some(ev) = reader.next() {
if let Some(v) = builder
- .feed(ev?, &Context::new(reader.language()))
+ .feed(ev?, &Context::empty().with_language(reader.language()))
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?
{
return Ok(v);