Implement dissimilar-origin postMessage.

components/script/dom/browsingcontext.rs

@@ -29,6 +29,7 @@ use js::jsapi::{MutableHandle, MutableHandleObject, MutableHandleValue};
 use js::jsapi::{ObjectOpResult, PropertyDescriptor};
 use js::jsval::{UndefinedValue, PrivateValue};
 use js::rust::get_object_class;
+use msg::constellation_msg::FrameId;
 use msg::constellation_msg::PipelineId;
 use std::cell::Cell;
 use std::ptr;
@@ -45,6 +46,11 @@ pub struct BrowsingContext {
     /// changes Window.
     reflector: Reflector,
 
+    /// The frame id of the browsing context.
+    /// In the case that this is a nested browsing context, this is the frame id
+    /// of the container.
+    frame_id: FrameId,
+
     /// The pipeline id of the currently active document.
     /// May be None, when the currently active document is in another script thread.
     /// We do not try to keep the pipeline id for documents in other threads,
@@ -60,9 +66,14 @@ pub struct BrowsingContext {
 }
 
 impl BrowsingContext {
-    pub fn new_inherited(currently_active: PipelineId, frame_element: Option<&Element>) -> BrowsingContext {
+    pub fn new_inherited(frame_id: FrameId,
+                         currently_active: PipelineId,
+                         frame_element: Option<&Element>)
+                         -> BrowsingContext
+    {
         BrowsingContext {
             reflector: Reflector::new(),
+            frame_id: frame_id,
             currently_active: Cell::new(Some(currently_active)),
             discarded: Cell::new(false),
             frame_element: frame_element.map(JS::from_ref),
@@ -70,7 +81,7 @@ impl BrowsingContext {
     }
 
     #[allow(unsafe_code)]
-    pub fn new(window: &Window, frame_element: Option<&Element>) -> Root<BrowsingContext> {
+    pub fn new(window: &Window, frame_id: FrameId, frame_element: Option<&Element>) -> Root<BrowsingContext> {
         unsafe {
             let WindowProxyHandler(handler) = window.windowproxy_handler();
             assert!(!handler.is_null());
@@ -87,7 +98,7 @@ impl BrowsingContext {
 
             // Create a new browsing context.
             let currently_active = window.global().pipeline_id();
-            let mut browsing_context = box BrowsingContext::new_inherited(currently_active, frame_element);
+            let mut browsing_context = box BrowsingContext::new_inherited(frame_id, currently_active, frame_element);
 
             // The window proxy owns the browsing context.
             // When we finalize the window proxy, it drops the browsing context it owns.
@@ -111,6 +122,10 @@ impl BrowsingContext {
         self.discarded.get()
     }
 
+    pub fn frame_id(&self) -> FrameId {
+        self.frame_id
+    }
+
     pub fn frame_element(&self) -> Option<&Element> {
         self.frame_element.r()
     }

components/script/dom/dissimilaroriginwindow.rs

@@ -4,9 +4,12 @@
 
 use dom::bindings::codegen::Bindings::DissimilarOriginWindowBinding;
 use dom::bindings::codegen::Bindings::DissimilarOriginWindowBinding::DissimilarOriginWindowMethods;
+use dom::bindings::error::{Error, ErrorResult};
+use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{JS, MutNullableJS, Root};
 use dom::bindings::reflector::DomObject;
 use dom::bindings::str::DOMString;
+use dom::bindings::structuredclone::StructuredCloneData;
 use dom::browsingcontext::BrowsingContext;
 use dom::dissimilaroriginlocation::DissimilarOriginLocation;
 use dom::globalscope::GlobalScope;
@@ -15,6 +18,9 @@ use ipc_channel::ipc;
 use js::jsapi::{JSContext, HandleValue};
 use js::jsval::{JSVal, UndefinedValue};
 use msg::constellation_msg::PipelineId;
+use script_traits::ScriptMsg as ConstellationMsg;
+use servo_url::ImmutableOrigin;
+use servo_url::ServoUrl;
 
 /// Represents a dissimilar-origin `Window` that exists in another script thread.
 ///
@@ -107,8 +113,27 @@ impl DissimilarOriginWindowMethods for DissimilarOriginWindow {
 
     #[allow(unsafe_code)]
     // https://html.spec.whatwg.org/multipage/#dom-window-postmessage
-    unsafe fn PostMessage(&self, _: *mut JSContext, _: HandleValue, _: DOMString) {
-        // TODO: Implement x-origin postMessage
+    unsafe fn PostMessage(&self, cx: *mut JSContext, message: HandleValue, origin: DOMString) -> ErrorResult {
+        // Step 3-5.
+        let origin = match &origin[..] {
+            "*" => None,
+            "/" => {
+                // TODO: Should be the origin of the incumbent settings object.
+                None
+            },
+            url => match ServoUrl::parse(&url) {
+                Ok(url) => Some(url.origin()),
+                Err(_) => return Err(Error::Syntax),
+            }
+        };
+
+        // Step 1-2, 6-8.
+        // TODO(#12717): Should implement the `transfer` argument.
+        let data = try!(StructuredCloneData::write(cx, message));
+
+        // Step 9.
+        self.post_message(origin, data);
+        Ok(())
     }
 
     #[allow(unsafe_code)]
@@ -139,3 +164,10 @@ impl DissimilarOriginWindowMethods for DissimilarOriginWindow {
         self.location.or_init(|| DissimilarOriginLocation::new(self))
     }
 }
+
+impl DissimilarOriginWindow {
+    pub fn post_message(&self, origin: Option<ImmutableOrigin>, data: StructuredCloneData) {
+        let msg = ConstellationMsg::PostMessage(self.browsing_context.frame_id(), origin, data.move_to_arraybuffer());
+        let _ = self.upcast::<GlobalScope>().constellation_chan().send(msg);
+    }
+}

components/script/dom/webidls/DissimilarOriginWindow.webidl

@@ -25,7 +25,7 @@ interface DissimilarOriginWindow : GlobalScope {
 
   void close();
   readonly attribute boolean closed;
-  void postMessage(any message, DOMString targetOrigin);
+  [Throws] void postMessage(any message, DOMString targetOrigin);
   attribute any opener;
   void blur();
   void focus();

components/script/dom/window.rs

@@ -718,10 +718,7 @@ impl WindowMethods for Window {
         let data = try!(StructuredCloneData::write(cx, message));
 
         // Step 9.
-        let runnable = PostMessageHandler::new(self, origin, data);
-        let msg = CommonScriptMsg::RunnableMsg(ScriptThreadEventCategory::DomEvent, box runnable);
-        // TODO(#12718): Use the "posted message task source".
-        let _ = self.script_chan.send(msg);
+        self.post_message(origin, data);
         Ok(())
     }
 
@@ -1910,3 +1907,12 @@ impl Runnable for PostMessageHandler {
                                      message.handle());
     }
 }
+
+impl Window {
+    pub fn post_message(&self, origin: Option<ImmutableOrigin>, data: StructuredCloneData) {
+        let runnable = PostMessageHandler::new(self, origin, data);
+        let msg = CommonScriptMsg::RunnableMsg(ScriptThreadEventCategory::DomEvent, box runnable);
+        // TODO(#12718): Use the "posted message task source".
+        let _ = self.script_chan.send(msg);
+    }
+}