Bug 634435: Add a property to expose the current pushState-state. r=jlebar a=beltzner

content/base/public/nsIDocument.h

@@ -55,6 +55,7 @@
 #include "nsHashKeys.h"
 #include "nsNodeInfoManager.h"
 #include "nsIStreamListener.h"
+#include "nsIVariant.h"
 #include "nsIObserver.h"
 #include "nsGkAtoms.h"
 #include "nsAutoPtr.h"
@@ -1422,26 +1423,13 @@ public:
     Doc_Theme_Bright
   };
 
-  /**
-   * Returns the document's pending state object (serialized to JSON), or the
-   * empty string if one doesn't exist.
-   *
-   * This field serves as a waiting place for the history entry's state object:
-   * We set the field's value to the history entry's state object early on in
-   * the load, then after we fire onload we deserialize the field's value and
-   * fire a popstate event containing the resulting object.
-   */
-  nsAString& GetPendingStateObject()
-  {
-    return mPendingStateObject;
-  }
-
   /**
    * Set the document's pending state object (as serialized to JSON).
    */
-  void SetPendingStateObject(nsAString &obj)
+  void SetCurrentStateObject(nsAString &obj)
   {
-    mPendingStateObject.Assign(obj);
+    mCurrentStateObject.Assign(obj);
+    mCurrentStateObjectCached = nsnull;
   }
 
   /**
@@ -1736,7 +1724,7 @@ protected:
    */
   PRUint32 mExternalScriptsBeingEvaluated;
 
-  nsString mPendingStateObject;
+  nsString mCurrentStateObject;
 
   // Weak reference to mScriptGlobalObject QI:d to nsPIDOMWindow,
   // updated on every set of mSecriptGlobalObject.
@@ -1752,6 +1740,8 @@ protected:
 
   // Our base target.
   nsString mBaseTarget;
+
+  nsCOMPtr<nsIVariant> mCurrentStateObjectCached;
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsIDocument, NS_IDOCUMENT_IID)

content/base/src/nsDocument.cpp

@@ -104,6 +104,7 @@
 #include "nsDOMError.h"
 #include "nsIPresShell.h"
 #include "nsPresContext.h"
+#include "nsIJSON.h"
 #include "nsThreadUtils.h"
 #include "nsNodeInfoManager.h"
 #include "nsIXBLService.h"
@@ -1726,6 +1727,7 @@ NS_INTERFACE_TABLE_HEAD(nsDocument)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIRadioGroupContainer)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIMutationObserver)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIApplicationCacheContainer)
+    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMNSDocument_MOZILLA_2_0_BRANCH)
   NS_OFFSET_AND_INTERFACE_TABLE_END
   NS_OFFSET_AND_INTERFACE_TABLE_TO_MAP_SEGUE
   NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(nsDocument)
@@ -1905,6 +1907,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsDocument)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mDOMImplementation)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mOriginalDocument)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mCachedEncoder)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mCurrentStateObjectCached)
 
   // Traverse all our nsCOMArrays.
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMARRAY(mStyleSheets)
@@ -8122,6 +8125,52 @@ nsIDocument::ScheduleBeforePaintEvent(nsIAnimationFrameListener* aListener)
 
 }
 
+NS_IMETHODIMP
+nsDocument::GetMozCurrentStateObject(nsIVariant** aState)
+{
+  // Get the document's current state object. This is the object returned form
+  // both document.mozCurrentStateObject as well as popStateEvent.state
+
+  nsCOMPtr<nsIVariant> stateObj;
+  // Parse the JSON, if there's any to parse.
+  if (!mCurrentStateObjectCached && !mCurrentStateObject.IsEmpty()) {
+    // Get the JSContext associated with this document. We need this for
+    // deserialization.
+    nsIScriptGlobalObject *sgo = GetScopeObject();
+    NS_ENSURE_TRUE(sgo, NS_ERROR_FAILURE);
+
+    nsIScriptContext *scx = sgo->GetContext();
+    NS_ENSURE_TRUE(scx, NS_ERROR_FAILURE);
+
+    JSContext *cx = (JSContext*) scx->GetNativeContext();
+
+    // Make sure we in the request while we have jsval on the native stack.
+    JSAutoRequest ar(cx);
+
+    // If our json call triggers a JS-to-C++ call, we want that call to use cx
+    // as the context.  So we push cx onto the context stack.
+    nsCxPusher cxPusher;
+
+    jsval jsStateObj = JSVAL_NULL;
+
+    // Deserialize the state object into an nsIVariant.
+    nsCOMPtr<nsIJSON> json = do_GetService("@mozilla.org/dom/json;1");
+    NS_ENSURE_TRUE(cxPusher.Push(cx), NS_ERROR_FAILURE);
+    nsresult rv = json->DecodeToJSVal(mCurrentStateObject, cx, &jsStateObj);
+    NS_ENSURE_SUCCESS(rv, rv);
+    cxPusher.Pop();
+
+    nsCOMPtr<nsIXPConnect> xpconnect = do_GetService(nsIXPConnect::GetCID());
+    NS_ENSURE_TRUE(xpconnect, NS_ERROR_FAILURE);
+    rv = xpconnect->JSValToVariant(cx, &jsStateObj, getter_AddRefs(mCurrentStateObjectCached));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  NS_IF_ADDREF(*aState = mCurrentStateObjectCached);
+  
+  return NS_OK;
+}
+
 nsresult
 nsDocument::AddImage(imgIRequest* aImage)
 {

content/base/src/nsDocument.h

@@ -517,7 +517,8 @@ class nsDocument : public nsIDocument,
                    public nsIScriptObjectPrincipal,
                    public nsIRadioGroupContainer,
                    public nsIApplicationCacheContainer,
-                   public nsStubMutationObserver
+                   public nsStubMutationObserver,
+                   public nsIDOMNSDocument_MOZILLA_2_0_BRANCH
 {
 public:
   typedef mozilla::dom::Element Element;
@@ -808,6 +809,7 @@ public:
 
   // nsIDOMNSDocument
   NS_DECL_NSIDOMNSDOCUMENT
+  NS_DECL_NSIDOMNSDOCUMENT_MOZILLA_2_0_BRANCH
 
   // nsIDOMDocumentEvent
   NS_DECL_NSIDOMDOCUMENTEVENT

docshell/base/nsDocShell.cpp

@@ -6074,7 +6074,7 @@ nsDocShell::EndPageLoad(nsIWebProgress * aProgress,
     if (!mEODForCurrentDocument && mContentViewer) {
         // Set the pending state object which will be returned to the page in
         // the popstate event.
-        SetDocPendingStateObj(mLSHE);
+        SetDocCurrentStateObj(mLSHE);
 
         mIsExecutingOnLoadHandler = PR_TRUE;
         rv = mContentViewer->LoadComplete(aStatus);
@@ -7766,7 +7766,7 @@ nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
 }
 
 nsresult
-nsDocShell::SetDocPendingStateObj(nsISHEntry *shEntry)
+nsDocShell::SetDocCurrentStateObj(nsISHEntry *shEntry)
 {
     nsresult rv;
 
@@ -7782,7 +7782,7 @@ nsDocShell::SetDocPendingStateObj(nsISHEntry *shEntry)
         // empty string.
     }
 
-    document->SetPendingStateObject(stateData);
+    document->SetCurrentStateObject(stateData);
     return NS_OK;
 }
 
@@ -8432,7 +8432,7 @@ nsDocShell::InternalLoad(nsIURI * aURI,
                 doc->SetDocumentURI(newURI);
             }
 
-            SetDocPendingStateObj(mOSHE);
+            SetDocCurrentStateObj(mOSHE);
 
             // Dispatch the popstate and hashchange events, as appropriate.
             nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(mScriptGlobal);

docshell/base/nsDocShell.h

@@ -564,10 +564,10 @@ protected:
                                  nsIChannel * aChannel,
                                  nsresult aResult);
 
-    // Sets the current document's pending state object to the given SHEntry's
-    // state object.  The pending state object is eventually given to the page
+    // Sets the current document's current state object to the given SHEntry's
+    // state object.  The current state object is eventually given to the page
     // in the PopState event.
-    nsresult SetDocPendingStateObj(nsISHEntry *shEntry);
+    nsresult SetDocCurrentStateObj(nsISHEntry *shEntry);
 
     nsresult CheckLoadingPermissions();
 

dom/base/nsDOMClassInfo.cpp

@@ -2193,7 +2193,8 @@ nsDOMClassInfo::WrapNativeParent(JSContext *cx, JSObject *scope,
     DOM_CLASSINFO_MAP_ENTRY(nsIDOM3Document)                                  \
     DOM_CLASSINFO_MAP_ENTRY(nsIDOM3Node)                                      \
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMXPathEvaluator)                             \
-    DOM_CLASSINFO_MAP_ENTRY(nsIDOMNodeSelector)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMNodeSelector)                               \
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMNSDocument_MOZILLA_2_0_BRANCH)
 
 
 #define DOM_CLASSINFO_GENERIC_HTML_MAP_ENTRIES                                \

dom/base/nsGlobalWindow.cpp

@@ -183,7 +183,6 @@
 #include "nsIXULAppInfo.h"
 #include "nsNetUtil.h"
 #include "nsFocusManager.h"
-#include "nsIJSON.h"
 #include "nsIXULWindow.h"
 #include "nsEventStateManager.h"
 #ifdef MOZ_XUL
@@ -7717,60 +7716,17 @@ nsGlobalWindow::DispatchSyncPopState(PRBool aIsInitial)
     return NS_OK;
   }
 
-  // Bail if there's no document or the document's readystate isn't "complete".
-  if (!mDoc) {
-    return NS_OK;
-  }
-
-  nsIDocument::ReadyState readyState = mDoc->GetReadyStateEnum();
-  if (readyState != nsIDocument::READYSTATE_COMPLETE) {
-    return NS_OK;
-  }
-
   // Get the document's pending state object -- it contains the data we're
   // going to send along with the popstate event.  The object is serialized as
   // JSON.
-  nsAString& stateObjJSON = mDoc->GetPendingStateObject();
-
   nsCOMPtr<nsIVariant> stateObj;
-  // Parse the JSON, if there's any to parse.
-  if (!stateObjJSON.IsEmpty()) {
-    // Get the JSContext associated with our document. We need this for
-    // deserialization.
-    nsCOMPtr<nsIDocument> document = do_QueryInterface(mDocument);
-    NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);
-
-    // Get the JSContext from the document, like we do in
-    // nsContentUtils::GetContextFromDocument().
-    nsIScriptGlobalObject *sgo = document->GetScopeObject();
-    NS_ENSURE_TRUE(sgo, NS_ERROR_FAILURE);
-
-    nsIScriptContext *scx = sgo->GetContext();
-    NS_ENSURE_TRUE(scx, NS_ERROR_FAILURE);
-
-    JSContext *cx = (JSContext*) scx->GetNativeContext();
-
-    // Make sure we in the request while we have jsval on the native stack.
-    JSAutoRequest ar(cx);
-
-    // If our json call triggers a JS-to-C++ call, we want that call to use cx
-    // as the context.  So we push cx onto the context stack.
-    nsCxPusher cxPusher;
-
-    jsval jsStateObj = JSVAL_NULL;
-
-    // Deserialize the state object into an nsIVariant.
-    nsCOMPtr<nsIJSON> json = do_GetService("@mozilla.org/dom/json;1");
-    NS_ENSURE_TRUE(cxPusher.Push(cx), NS_ERROR_FAILURE);
-    rv = json->DecodeToJSVal(stateObjJSON, cx, &jsStateObj);
-    NS_ENSURE_SUCCESS(rv, rv);
-    cxPusher.Pop();
-
-    nsCOMPtr<nsIXPConnect> xpconnect = do_GetService(nsIXPConnect::GetCID());
-    NS_ENSURE_TRUE(xpconnect, NS_ERROR_FAILURE);
-    rv = xpconnect->JSValToVariant(cx, &jsStateObj, getter_AddRefs(stateObj));
-    NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIDOMNSDocument_MOZILLA_2_0_BRANCH> doc2 = do_QueryInterface(mDoc);
+  if (!doc2) {
+    return NS_OK;
   }
+  
+  rv = doc2->GetMozCurrentStateObject(getter_AddRefs(stateObj));
+  NS_ENSURE_SUCCESS(rv, rv);
 
   // Obtain a presentation shell for use in creating a popstate event.
   nsIPresShell *shell = mDoc->GetShell();

dom/interfaces/core/nsIDOMNSDocument.idl

@@ -42,6 +42,7 @@
 
 interface nsIBoxObject;
 interface nsIDOMLocation;
+interface nsIVariant;
 
 [scriptable, uuid(92f2c6f8-3668-4a47-8251-2a900afe11fa)]
 interface nsIDOMNSDocument : nsISupports
@@ -129,3 +130,9 @@ interface nsIDOMNSDocument : nsISupports
   void mozSetImageElement(in DOMString aImageElementId,
                           in nsIDOMElement aImageElement);
 };
+
+[scriptable, uuid(fee67aed-3b94-4136-ad7d-fb88ef23f45f)]
+interface nsIDOMNSDocument_MOZILLA_2_0_BRANCH : nsISupports
+{
+  readonly attribute nsIVariant mozCurrentStateObject;
+};

dom/tests/mochitest/whatwg/test_bug500328.html

@@ -222,6 +222,8 @@ function runTest() {
   popstateExpected("Going back to page 1 should trigger a popstate.");
   is(JSON.stringify(gLastPopStateEvent.state), JSON.stringify(testObj1),
      "Wrong state object popped after going back to page 1.");
+  ok(gLastPopStateEvent.state === iframeCw.document.mozCurrentStateObject,
+     "Wrong state object in document after going back to page 1.");
   ok(iframeCw.location.toString().match(/file_bug500328_1.html$/),
       "Going back to page 1 hould take us to original page.");
 
@@ -229,6 +231,8 @@ function runTest() {
   popstateExpected("Going back to page 0 should trigger a popstate.");
   is(gLastPopStateEvent.state, null,
       "Going back to page 0 should pop a null state.");
+  is(iframeCw.document.mozCurrentStateObject, null,
+      "Going back to page 0 should pop a null state.");
   is(iframeCw.location.search, "",
       "Going back to page 0 should clear the querystring.");
 
@@ -236,6 +240,8 @@ function runTest() {
   popstateExpected("Going forward to page 1 should trigger a popstate.");
   is(JSON.stringify(gLastPopStateEvent.state), JSON.stringify(testObj1),
       "Wrong state object popped after going forward to page 1.");
+  ok(gLastPopStateEvent.state === iframeCw.document.mozCurrentStateObject,
+      "Wrong state object in document after going forward to page 1.");
   ok(iframeCw.location.toString().match(/file_bug500328_1.html$/),
       "Going forward to page 1 should leave us at original page.");
 
@@ -246,6 +252,8 @@ function runTest() {
   popstateExpected("Going forward to page 2 should trigger a popstate.");
   is(JSON.stringify(gLastPopStateEvent.state), JSON.stringify(testObj2),
      "Wrong state object popped after going forward to page 2.");
+  ok(iframeCw.document.mozCurrentStateObject === gLastPopStateEvent.state,
+     "Wrong state object in document after going forward to page 2.");
   ok(iframeCw.location.toString().match(/file_bug500328_1.html\?test1#foo$/),
      "Going forward to page 2 took us to " + iframeCw.location.toString());