Add skipping of unrecognized elements (fixes #12)

yaserde/src/de/mod.rs

@@ -88,6 +88,16 @@ impl<'de, R: Read> Deserializer<R> {
     Ok(next_event)
   }
 
+  pub fn skip_element(&mut self, mut cb: impl FnMut(&XmlEvent)) -> Result<(), String> {
+    let depth = self.depth;
+
+    while self.depth >= depth {
+      cb(&self.next_event()?);
+    }
+
+    Ok(())
+  }
+
   pub fn set_map_value(&mut self) {
     self.is_map_value = true;
   }

yaserde/tests/deserializer.rs

@@ -780,3 +780,45 @@ fn de_flatten() {
     }
   );
 }
+
+#[test]
+fn de_subitem_issue_12() {
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct Struct {
+    id: i32,
+  }
+
+  convert_and_validate!(
+    r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <Struct>
+      <id>54</id>
+      <SubStruct>
+        <id>86</id>
+      </SubStruct>
+    </Struct>
+    "#,
+    Struct,
+    Struct { id: 54 }
+  );
+}
+
+#[test]
+fn de_subitem_issue_12_attributes() {
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct Struct {
+    #[yaserde(attribute)]
+    id: i32,
+  }
+
+  convert_and_validate!(
+    r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <Struct id="54">
+      <SubStruct id="86" />
+    </Struct>
+    "#,
+    Struct,
+    Struct { id: 54 }
+  );
+}

yaserde_derive/src/de/expand_struct.rs

@@ -440,23 +440,36 @@ pub fn parse(
         #field_visitors
         #init_unused
 
+        let mut depth = 0;
+
         loop {
           let event = reader.peek()?.to_owned();
 
           match event {
             XmlEvent::StartElement{ref name, ref attributes, ..} => {
+              let mut skipped = false;
 
               match name.local_name.as_str() {
                 #call_visitors
                 named_element => {
                   let event = reader.next_event()?;
                   #write_unused
+
+                  if depth > 0 { // Don't skip root element
+                    skipped = true;
+                    reader.skip_element(|event| {
+                      #write_unused
+                    })?;
+                  }
                 }
                 // name => {
                 //   return Err(format!("unknown key {}", name))
                 // }
               }
-              #attributes_loading
+              if !skipped {
+                #attributes_loading
+              }
+              depth += 1;
             }
             XmlEvent::EndElement{ref name} => {
               if name.local_name == named_element {
@@ -465,6 +478,7 @@ pub fn parse(
               }
               let event = reader.next_event()?;
               #write_unused
+              depth -= 1;
             }
             XmlEvent::Characters(ref text_content) => {
               #set_text