LibWeb: Implement Document.evaluate and related XPath methods

Author: https://github.com/johannesg
Commit: d2030a5377
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6342
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/DOM/Document.cpp

@@ -6802,6 +6802,23 @@ HashMap<FlyString, GC::Ref<Web::CSS::CSSPropertyRule>>& Document::registered_cus
     return m_registered_custom_properties;
 }
 
+WebIDL::ExceptionOr<GC::Ref<XPath::XPathExpression>> Document::create_expression(String const& expression, GC::Ptr<XPath::XPathNSResolver> resolver)
+{
+    auto& realm = this->realm();
+    return XPath::create_expression(realm, expression, resolver);
+}
+
+WebIDL::ExceptionOr<GC::Ref<XPath::XPathResult>> Document::evaluate(String const& expression, DOM::Node const& context_node, GC::Ptr<XPath::XPathNSResolver> resolver, WebIDL::UnsignedShort type, GC::Ptr<XPath::XPathResult> result)
+{
+    auto& realm = this->realm();
+    return XPath::evaluate(realm, expression, context_node, resolver, type, result);
+}
+
+GC::Ref<DOM::Node> Document::create_ns_resolver(GC::Ref<DOM::Node> node_resolver)
+{
+    return node_resolver;
+}
+
 NonnullRefPtr<CSS::StyleValue const> Document::custom_property_initial_value(FlyString const& name) const
 {
     auto maybe_custom_property = m_registered_custom_properties.get(name);

Libraries/LibWeb/DOM/Document.h

@@ -45,6 +45,7 @@
 #include <LibWeb/ViewTransition/ViewTransition.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 #include <LibWeb/WebIDL/ObservableArray.h>
+#include <LibWeb/XPath/XPath.h>
 
 namespace Web::DOM {
 
@@ -682,6 +683,10 @@ public:
     WebIDL::ExceptionOr<bool> query_command_supported(FlyString const& command);
     WebIDL::ExceptionOr<String> query_command_value(FlyString const& command);
 
+    WebIDL::ExceptionOr<GC::Ref<XPath::XPathExpression>> create_expression(String const& expression, GC::Ptr<XPath::XPathNSResolver> resolver = nullptr);
+    WebIDL::ExceptionOr<GC::Ref<XPath::XPathResult>> evaluate(String const& expression, const DOM::Node& context_node, GC::Ptr<XPath::XPathNSResolver> resolver = nullptr, WebIDL::UnsignedShort type = 0, GC::Ptr<XPath::XPathResult> result = nullptr);
+    GC::Ref<DOM::Node> create_ns_resolver(GC::Ref<DOM::Node> node_resolver); // legacy
+
     // https://w3c.github.io/selection-api/#dfn-has-scheduled-selectionchange-event
     bool has_scheduled_selectionchange_event() const { return m_has_scheduled_selectionchange_event; }
     void set_scheduled_selectionchange_event(bool value) { m_has_scheduled_selectionchange_event = value; }

Libraries/LibWeb/DOM/Document.idl

@@ -27,6 +27,8 @@
 #import <HTML/Location.idl>
 #import <Selection/Selection.idl>
 #import <ViewTransition/ViewTransition.idl>
+#import <XPath/XPathResult.idl>
+#import <XPath/XPathExpression.idl>
 
 // https://dom.spec.whatwg.org/#document
 // https://html.spec.whatwg.org/multipage/dom.html#the-document-object
@@ -153,6 +155,11 @@ interface Document : Node {
     boolean queryCommandSupported(DOMString commandId);
     DOMString queryCommandValue(DOMString commandId);
 
+    // XPath
+    [NewObject] XPathExpression createExpression(DOMString expression, optional XPathNSResolver? resolver = null);
+    XPathResult evaluate(DOMString expression, Node contextNode, optional XPathNSResolver? resolver = null, optional unsigned short type = 0, optional XPathResult? result = null);
+    Node createNSResolver(Node nodeResolver); // legacy
+
     // special event handler IDL attributes that only apply to Document objects
     [LegacyLenientThis] attribute EventHandler onreadystatechange;
     attribute EventHandler onvisibilitychange;