Implement querySelector for Document

src/components/script/dom/document.rs

@@ -12,7 +12,8 @@ use dom::bindings::js::{JS, JSRef, Temporary, OptionalSettable, TemporaryPushabl
 use dom::bindings::js::OptionalRootable;
 use dom::bindings::trace::Untraceable;
 use dom::bindings::utils::{Reflectable, Reflector, reflect_dom_object};
-use dom::bindings::error::{ErrorResult, Fallible, NotSupported, InvalidCharacter, HierarchyRequest, NamespaceError};
+use dom::bindings::error::{ErrorResult, Fallible, NotSupported, InvalidCharacter};
+use dom::bindings::error::{HierarchyRequest, NamespaceError};
 use dom::bindings::utils::{xml_name_type, InvalidXMLName, Name, QName};
 use dom::comment::Comment;
 use dom::customevent::CustomEvent;
@@ -806,13 +807,16 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
         window.Location()
     }
 
+    // http://dom.spec.whatwg.org/#dom-parentnode-children
     fn Children(&self) -> Temporary<HTMLCollection> {
         let window = self.window.root();
         HTMLCollection::children(&*window, NodeCast::from_ref(self))
     }
 
+    // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
     fn QuerySelector(&self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
-        Ok(None)
+        let root: &JSRef<Node> = NodeCast::from_ref(self);
+        root.query_selector(selectors)
     }
 
     fn GetOnload(&self) -> Option<EventHandlerNonNull> {

src/components/script/dom/node.rs

@@ -15,7 +15,7 @@ use dom::bindings::js::{JS, JSRef, RootedReference, Temporary, Root, OptionalUnr
 use dom::bindings::js::{OptionalSettable, TemporaryPushable, OptionalRootedRootable};
 use dom::bindings::js::{ResultRootable, OptionalRootable};
 use dom::bindings::utils::{Reflectable, Reflector, reflect_dom_object};
-use dom::bindings::error::{ErrorResult, Fallible, NotFound, HierarchyRequest};
+use dom::bindings::error::{ErrorResult, Fallible, NotFound, HierarchyRequest, Syntax};
 use dom::bindings::utils;
 use dom::characterdata::{CharacterData, CharacterDataMethods};
 use dom::comment::Comment;
@@ -36,6 +36,7 @@ use layout_interface::{ContentBoxQuery, ContentBoxResponse, ContentBoxesQuery, C
                        LayoutChan, ReapLayoutDataMsg, TrustedNodeAddress, UntrustedNodeAddress};
 use servo_util::geometry::Au;
 use servo_util::str::{DOMString, null_str_as_empty};
+use style::{parse_selector_list, matches_compound_selector, NamespaceMap};
 
 use js::jsapi::{JSContext, JSObject, JSRuntime};
 use js::jsfriendapi;
@@ -396,6 +397,8 @@ pub trait NodeHelpers {
     fn get_bounding_content_box(&self) -> Rect<Au>;
     fn get_content_boxes(&self) -> Vec<Rect<Au>>;
 
+    fn query_selector(&self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>>;
+
     fn remove_self(&self);
 }
 
@@ -552,6 +555,30 @@ impl<'a> NodeHelpers for JSRef<'a, Node> {
         rects
     }
 
+    // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
+    fn query_selector(&self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
+        // Step 1.
+        let namespace = NamespaceMap::new();
+        match parse_selector_list(tokenize(selectors.as_slice()).map(|(token, _)| token).collect(), &namespace) {
+            // Step 2.
+            None => return Err(Syntax),
+            // Step 3.
+            Some(ref selectors) => {
+                for selector in selectors.iter() {
+                    assert!(selector.pseudo_element.is_none());
+                    for elem in self.child_elements() {
+                        let node: &JSRef<Node> = NodeCast::from_ref(&elem);
+                        let mut _shareable: bool = false;
+                        if matches_compound_selector(selector.compound_selectors.deref(), node, &mut _shareable) {
+                            return Ok(Some(Temporary::from_rooted(&elem)));
+                        }
+                    }
+                }
+            }
+        }
+        Ok(None)
+    }
+
     fn ancestors(&self) -> AncestorIterator {
         AncestorIterator {
             current: self.parent_node.get().map(|node| (*node.root()).clone()),

src/components/script/script.rs

@@ -17,6 +17,7 @@
 extern crate log;
 
 extern crate debug;
+extern crate cssparser;
 extern crate collections;
 extern crate geom;
 extern crate hubbub;

src/components/style/selector_matching.rs

@@ -521,7 +521,7 @@ impl Ord for MatchedProperty {
 /// `shareable` to false unless you are willing to update the style sharing logic. Otherwise things
 /// will almost certainly break as nodes will start mistakenly sharing styles. (See the code in
 /// `main/css/matching.rs`.)
-fn matches_compound_selector<E:TElement,
+pub fn matches_compound_selector<E:TElement,
                              N:TNode<E>>(
                              selector: &CompoundSelector,
                              element: &N,

src/components/style/style.rs

@@ -33,7 +33,7 @@ extern crate servo_util = "util";
 // Public API
 pub use stylesheets::{Stylesheet, CSSRule, StyleRule};
 pub use selector_matching::{Stylist, StylesheetOrigin, UserAgentOrigin, AuthorOrigin, UserOrigin};
-pub use selector_matching::{MatchedProperty};
+pub use selector_matching::{MatchedProperty, matches_compound_selector};
 pub use properties::{cascade, cascade_anonymous};
 pub use properties::{PropertyDeclaration, ComputedValues, computed_values, style_structs};
 pub use properties::{PropertyDeclarationBlock, parse_style_attribute};  // Style attributes
@@ -43,6 +43,7 @@ pub use errors::with_errors_silenced;
 pub use node::{TElement, TNode};
 pub use selectors::{PseudoElement, Before, After, AttrSelector, SpecificNamespace, AnyNamespace};
 pub use selectors::{NamespaceConstraint, Selector, CompoundSelector, SimpleSelector, Combinator};
+pub use selectors::{parse_selector_list};
 pub use namespaces::NamespaceMap;
 pub use media_queries::{MediaRule, MediaQueryList, MediaQuery, Device, MediaType, MediaQueryType};