Bug 415772, use XMLHttpRequest to load xml datasources, r=smaug,sr=peterv

content/xul/templates/public/nsIXULTemplateBuilder.idl

@@ -158,7 +158,7 @@ interface nsIXULTemplateQueryProcessor;
  *
  * See http://wiki.mozilla.org/XUL:Templates_Plan for details about templates.
  */
-[scriptable, uuid(fd8fe8a1-5dc3-4830-84b7-f75baccb4a9b)]
+[scriptable, uuid(1762801E-1147-4197-BF0D-D749C903AF74)]
 interface nsIXULTemplateBuilder : nsISupports
 {
     /**
@@ -166,10 +166,24 @@ interface nsIXULTemplateBuilder : nsISupports
      */
     readonly attribute nsIDOMElement root;
 
+    /**
+     * The opaque datasource object that is used for the template. This object
+     * is created by the getDataSource method of the query processor. May be
+     * null if the datasource has not been loaded yet. Set this attribute to
+     * use a different datasource and rebuild the template.
+     *
+     * For an RDF datasource, this will be the same as the database. For XML
+     * this will be the nsIDOMNode for the datasource document or node for
+     * an inline reference (such as #name). Other query processors may use
+     * other types for the datasource.
+     */
+    attribute nsISupports datasource;
+
     /**
      * The composite datasource that the template builder observes
-     * and uses to create content. This is used only for RDF queries and
-     * is maintained for backwards compatibility.
+     * and uses to create content. This is used only for RDF queries and is
+     * maintained for backwards compatibility. It will be the same object as
+     * the datasource property. For non-RDF queries, it will always be null.
      */
     readonly attribute nsIRDFCompositeDataSource database;
 

content/xul/templates/src/nsXULTemplateBuilder.cpp

@@ -320,6 +320,25 @@ nsXULTemplateBuilder::GetRoot(nsIDOMElement** aResult)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsXULTemplateBuilder::GetDatasource(nsISupports** aResult)
+{
+    if (mCompDB)
+        NS_ADDREF(*aResult = mCompDB);
+    else
+        NS_IF_ADDREF(*aResult = mDataSource);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULTemplateBuilder::SetDatasource(nsISupports* aResult)
+{
+    mDataSource = aResult;
+    mCompDB = do_QueryInterface(mDataSource);
+
+    return Rebuild();
+}
+
 NS_IMETHODIMP
 nsXULTemplateBuilder::GetDatabase(nsIRDFCompositeDataSource** aResult)
 {

content/xul/templates/src/nsXULTemplateQueryProcessorXML.cpp

@@ -55,6 +55,7 @@
 #include "nsIArray.h"
 #include "nsContentUtils.h"
 #include "nsArrayUtils.h"
+#include "nsPIDOMWindow.h"
 
 #include "nsXULTemplateBuilder.h"
 #include "nsXULTemplateQueryProcessorXML.h"
@@ -109,9 +110,11 @@ nsXULTemplateResultSetXML::GetNext(nsISupports **aResult)
 NS_IMPL_CYCLE_COLLECTION_CLASS(nsXULTemplateQueryProcessorXML)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsXULTemplateQueryProcessorXML)
     NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mTemplateBuilder)
+    NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mRequest)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsXULTemplateQueryProcessorXML)
     NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mTemplateBuilder)
+    NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mRequest)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF_AMBIGUOUS(nsXULTemplateQueryProcessorXML,
                                           nsIXULTemplateQueryProcessor)
@@ -123,6 +126,14 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsXULTemplateQueryProcessorXML)
     NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIXULTemplateQueryProcessor)
 NS_INTERFACE_MAP_END
 
+/*
+ * Only the first datasource in aDataSource is used, which should be either an
+ * nsIURI of an XML document, or a DOM node. If the former, GetDatasource will
+ * load the document asynchronously and return null in aResult. Once the
+ * document has loaded, the builder's datasource will be set to the XML
+ * document. If the datasource is a DOM node, the node will be returned in
+ * aResult.
+ */
 NS_IMETHODIMP
 nsXULTemplateQueryProcessorXML::GetDatasource(nsIArray* aDataSources,
                                               nsIDOMNode* aRootNode,
@@ -141,6 +152,22 @@ nsXULTemplateQueryProcessorXML::GetDatasource(nsIArray* aDataSources,
     if (length == 0)
         return NS_OK;
 
+    // we get only the first item, because the query processor supports only
+    // one document as a datasource
+
+    nsCOMPtr<nsIDOMNode> node = do_QueryElementAt(aDataSources, 0);
+    if (node) {
+        return CallQueryInterface(node, aResult);
+    }
+
+    nsCOMPtr<nsIURI> uri = do_QueryElementAt(aDataSources, 0);
+    if (!uri)
+        return NS_ERROR_UNEXPECTED;
+
+    nsCAutoString uriStr;
+    rv = uri->GetSpec(uriStr);
+    NS_ENSURE_SUCCESS(rv, rv);
+
     nsCOMPtr<nsIContent> root = do_QueryInterface(aRootNode);
     if (!root)
         return NS_ERROR_UNEXPECTED;
@@ -149,52 +176,43 @@ nsXULTemplateQueryProcessorXML::GetDatasource(nsIArray* aDataSources,
     if (!doc)
         return NS_ERROR_UNEXPECTED;
 
-    nsIURI *docurl = doc->GetDocumentURI();
     nsIPrincipal *docPrincipal = doc->NodePrincipal();
-
-    // we get only the first item, because the query processor supports only
-    // one document as a datasource
-
-    nsCOMPtr<nsIDOMNode> node = do_QueryElementAt(aDataSources, 0);
-
-    if (node) {
-        return CallQueryInterface(node, aResult);
-    }
-
-    nsCOMPtr<nsIURI> uri = do_QueryElementAt(aDataSources,0);
-    if (!uri)
-        return NS_ERROR_UNEXPECTED;
+    nsCOMPtr<nsIURI> uri2;
+    docPrincipal->GetURI(getter_AddRefs(uri2));
 
     PRBool hasHadScriptObject = PR_TRUE;
     nsIScriptGlobalObject* scriptObject =
       doc->GetScriptHandlingObject(hasHadScriptObject);
     NS_ENSURE_STATE(scriptObject || !hasHadScriptObject);
-    nsAutoString emptyStr;
-    nsCOMPtr<nsIDOMDocument> domDocument;
-    rv = nsContentUtils::CreateDocument(emptyStr, emptyStr, nsnull,
-                                        docurl, doc->GetBaseURI(),
-                                        docPrincipal,
-                                        scriptObject,
-                                        getter_AddRefs(domDocument));
+
+    nsIScriptContext *context = scriptObject->GetContext();
+    NS_ENSURE_TRUE(context, NS_OK);
+
+    nsCOMPtr<nsIXMLHttpRequest> req =
+        do_CreateInstance(NS_XMLHTTPREQUEST_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsPIDOMWindow> owner = do_QueryInterface(scriptObject);
+    req->Init(docPrincipal, context, owner);
+
+    rv = req->OpenRequest(NS_LITERAL_CSTRING("GET"), uriStr, PR_TRUE,
+                          EmptyString(), EmptyString());
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIDOMEventTarget> target(do_QueryInterface(req));
+    rv = target->AddEventListener(NS_LITERAL_STRING("load"), this, PR_FALSE);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = target->AddEventListener(NS_LITERAL_STRING("error"), this, PR_FALSE);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = req->Send(nsnull);
     NS_ENSURE_SUCCESS(rv, rv);
 
     mTemplateBuilder = aBuilder;
-    nsCOMPtr<nsIDOMEventTarget> target = do_QueryInterface(domDocument);
-    target->AddEventListener(NS_LITERAL_STRING("load"), this, PR_FALSE);
-
-    nsCOMPtr<nsIDOMXMLDocument> xmldoc = do_QueryInterface(domDocument);
-
-    PRBool ok;
-    nsCAutoString uristrC;
-    uri->GetSpec(uristrC);
-
-    xmldoc->Load(NS_ConvertUTF8toUTF16(uristrC), &ok);
-
-    if (ok) {
-        *aShouldDelayBuilding = PR_TRUE;
-        return CallQueryInterface(domDocument, aResult);
-    }
+    mRequest = req;
 
+    *aShouldDelayBuilding = PR_TRUE;
     return NS_OK;
 }
 
@@ -455,20 +473,19 @@ nsXULTemplateQueryProcessorXML::HandleEvent(nsIDOMEvent* aEvent)
     aEvent->GetType(eventType);
 
     if (eventType.EqualsLiteral("load") && mTemplateBuilder) {
-        // remove the listener
-        nsCOMPtr<nsIDOMEventTarget> target;
-        aEvent->GetTarget(getter_AddRefs(target));
-        if (target) {
-            target->RemoveEventListener(NS_LITERAL_STRING("load"), this, PR_FALSE);
-        }
-
-        // rebuild the template
-        nsresult rv = mTemplateBuilder->Rebuild();
+        NS_ASSERTION(mRequest, "request was not set");
+        nsCOMPtr<nsIDOMDocument> doc;
+        if (NS_SUCCEEDED(mRequest->GetResponseXML(getter_AddRefs(doc))))
+            mTemplateBuilder->SetDatasource(doc);
 
         // to avoid leak. we don't need it after...
         mTemplateBuilder = nsnull;
-
-        return rv;
+        mRequest = nsnull;
     }
+    else if (eventType.EqualsLiteral("error")) {
+        mTemplateBuilder = nsnull;
+        mRequest = nsnull;
+    }
+
     return NS_OK;
 }

content/xul/templates/src/nsXULTemplateQueryProcessorXML.h

@@ -52,6 +52,7 @@
 #include "nsIDOMXPathResult.h"
 #include "nsXMLBinding.h"
 #include "nsCycleCollectionParticipant.h"
+#include "nsIXMLHttpRequest.h"
 
 class nsXULTemplateQueryProcessorXML;
 
@@ -185,6 +186,8 @@ private:
     nsCOMPtr<nsIDOMXPathEvaluator> mEvaluator;
 
     nsCOMPtr<nsIXULTemplateBuilder> mTemplateBuilder;
+
+    nsCOMPtr<nsIXMLHttpRequest> mRequest;
 };