add add_attrs_if_missing callback

src/html5ever/lib.rs

@@ -44,6 +44,7 @@ pub extern "C" fn html5ever_parse_document(
     pop_callback: PopCallback,
     create_comment_callback: CreateCommentCallback,
     append_doctype_to_document: AppendDoctypeToDocumentCallback,
+    add_attrs_if_missing_callback: AddAttrsIfMissingCallback,
 ) -> () {
     if html.is_null() || len == 0 {
         return ();
@@ -63,6 +64,7 @@ pub extern "C" fn html5ever_parse_document(
         create_element_callback: create_element_callback,
         create_comment_callback: create_comment_callback,
         append_doctype_to_document: append_doctype_to_document,
+        add_attrs_if_missing_callback: add_attrs_if_missing_callback,
     };
 
     let bytes = unsafe { std::slice::from_raw_parts(html, len) };
@@ -84,6 +86,7 @@ pub extern "C" fn html5ever_parse_fragment(
     pop_callback: PopCallback,
     create_comment_callback: CreateCommentCallback,
     append_doctype_to_document: AppendDoctypeToDocumentCallback,
+    add_attrs_if_missing_callback: AddAttrsIfMissingCallback,
 ) -> () {
     if html.is_null() || len == 0 {
         return ();
@@ -103,6 +106,7 @@ pub extern "C" fn html5ever_parse_fragment(
         create_element_callback: create_element_callback,
         create_comment_callback: create_comment_callback,
         append_doctype_to_document: append_doctype_to_document,
+        add_attrs_if_missing_callback: add_attrs_if_missing_callback,
     };
 
     let bytes = unsafe { std::slice::from_raw_parts(html, len) };
@@ -183,6 +187,7 @@ pub extern "C" fn html5ever_streaming_parser_create(
     pop_callback: PopCallback,
     create_comment_callback: CreateCommentCallback,
     append_doctype_to_document: AppendDoctypeToDocumentCallback,
+    add_attrs_if_missing_callback: AddAttrsIfMissingCallback,
 ) -> *mut c_void {
     let arena = Box::new(typed_arena::Arena::new());
 
@@ -205,6 +210,7 @@ pub extern "C" fn html5ever_streaming_parser_create(
         create_element_callback: create_element_callback,
         create_comment_callback: create_comment_callback,
         append_doctype_to_document: append_doctype_to_document,
+        add_attrs_if_missing_callback: add_attrs_if_missing_callback,
     };
 
     // Create a parser which implements TendrilSink for streaming parsing

src/html5ever/sink.rs

@@ -55,6 +55,7 @@ pub struct Sink<'arena> {
     pub create_element_callback: CreateElementCallback,
     pub create_comment_callback: CreateCommentCallback,
     pub append_doctype_to_document: AppendDoctypeToDocumentCallback,
+    pub add_attrs_if_missing_callback: AddAttrsIfMissingCallback,
 }
 
 impl<'arena> TreeSink for Sink<'arena> {
@@ -120,19 +121,6 @@ impl<'arena> TreeSink for Sink<'arena> {
         let data = self.arena.alloc(ElementData::new(name.clone(), flags));
 
         unsafe {
-            let mut c_attrs: Vec<CAttribute> = Vec::with_capacity(attrs.len());
-
-            for attr in attrs.iter() {
-                let v: &str = &attr.value;
-                c_attrs.push(CAttribute {
-                    name: CQualName::create(&attr.name),
-                    value: StringSlice {
-                        ptr: v.as_ptr(),
-                        len: attr.value.len(),
-                    },
-                })
-            }
-
             let mut attribute_iterator = CAttributeIterator { vec: attrs, pos: 0 };
 
             return (self.create_element_callback)(
@@ -226,9 +214,15 @@ impl<'arena> TreeSink for Sink<'arena> {
     }
 
     fn add_attrs_if_missing(&self, target: &Ref, attrs: Vec<Attribute>) {
-        _ = target;
-        _ = attrs;
-        panic!("add_attrs_if_missing");
+        unsafe {
+            let mut attribute_iterator = CAttributeIterator { vec: attrs, pos: 0 };
+
+            (self.add_attrs_if_missing_callback)(
+                self.ctx,
+                *target,
+                &mut attribute_iterator as *mut _ as *mut c_void,
+            );
+        }
     }
 
     fn remove_from_parent(&self, target: &Ref) {

src/html5ever/types.rs

@@ -51,6 +51,12 @@ pub type ParseErrorCallback = unsafe extern "C" fn(ctx: Ref, str: StringSlice) -
 
 pub type PopCallback = unsafe extern "C" fn(ctx: Ref, node: Ref) -> ();
 
+pub type AddAttrsIfMissingCallback = unsafe extern "C" fn(
+    ctx: Ref,
+    target: Ref,
+    attributes: *mut c_void,
+) -> ();
+
 pub type Ref = *const c_void;
 
 #[repr(C)]