Bug 235866 - add xulelement.builder.refresh and dynamically respond to changes in the datsources="" attribute. r+sr=bryner

content/xul/templates/public/nsIXULTemplateBuilder.idl

@@ -23,6 +23,7 @@
  *  Chris Waterson <waterson@netscape.com>
  *  Ben Goodger <ben@netscape.com>
  *  Jan Varga <varga@nixcorp.com>
+ *  Benjamin Smedberg <bsmedberg@covad.net>
  *
  *
  * Alternatively, the contents of this file may be used under the terms of
@@ -48,7 +49,7 @@ interface nsIXULBuilderListener;
 
 [ptr] native nsIContent_ptr(nsIContent);
 
-[scriptable, uuid(fb744f8e-1dd1-11b2-a5d7-935c9ab60602)]
+[scriptable, uuid(9da147a7-5854-49e3-a397-22ecdd93e96d)]
 interface nsIXULTemplateBuilder : nsISupports
 {
     /**
@@ -67,6 +68,15 @@ interface nsIXULTemplateBuilder : nsISupports
      */
     void rebuild();
 
+    /**
+     * Reload any of our RDF datasources that support nsIRDFRemoteDatasource. 
+     *
+     * @note This is a temporary hack so that remote-XUL authors can
+     *       reload remote datasources. When RDF becomes remote-scriptable,
+     *       this will no longer be necessary.
+     */
+    void refresh();
+
     /**
      * Called to initialize a XUL content builder on a particular root
      * element. This element presumably has a ``datasources''

content/xul/templates/src/nsXULTemplateBuilder.cpp

@@ -88,6 +88,7 @@
 #include "nsIScriptGlobalObject.h"
 #include "nsIServiceManager.h"
 #include "nsISecurityCheckedComponent.h"
+#include "nsISimpleEnumerator.h"
 #include "nsISupportsArray.h"
 #include "nsITimer.h"
 #include "nsIURL.h"
@@ -243,12 +244,48 @@ nsXULTemplateBuilder::Rebuild()
     return rv;
 }
 
+NS_IMETHODIMP
+nsXULTemplateBuilder::Refresh()
+{
+    nsresult rv;
+
+    nsCOMPtr<nsISimpleEnumerator> dslist;
+    rv = mDB->GetDataSources(getter_AddRefs(dslist));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    PRBool hasMore;
+    nsCOMPtr<nsISupports> next;
+    nsCOMPtr<nsIRDFRemoteDataSource> rds;
+
+    while(NS_SUCCEEDED(dslist->HasMoreElements(&hasMore)) && hasMore) {
+        dslist->GetNext(getter_AddRefs(next));
+        if (next && (rds = do_QueryInterface(next))) {
+            rds->Refresh(PR_FALSE);
+        }
+    }
+
+    return Rebuild();
+}   
+
 NS_IMETHODIMP
 nsXULTemplateBuilder::Init(nsIContent* aElement)
 {
     NS_PRECONDITION(aElement, "null ptr");
     mRoot = aElement;
-    return LoadDataSources();
+
+    nsCOMPtr<nsIDocument> doc = mRoot->GetDocument();
+    NS_ASSERTION(doc, "element has no document");
+    if (! doc)
+        return NS_ERROR_UNEXPECTED;
+
+    nsresult rv = LoadDataSources(doc);
+
+    if (NS_SUCCEEDED(rv)) {
+        // Add ourselves as a document observer
+        doc->AddObserver(this);
+    }
+
+    return rv;
 }
 
 NS_IMETHODIMP
@@ -289,11 +326,20 @@ nsXULTemplateBuilder::AttributeChanged(nsIDocument *aDocument,
                                        nsIAtom*     aAttribute,
                                        PRInt32      aModType)
 {
-    // Check for a change to the 'ref' attribute on an atom, in which
-    // case we may need to nuke and rebuild the entire content model
-    // beneath the element.
-    if ((aAttribute == nsXULAtoms::ref) && (aContent == mRoot))
-        Rebuild();
+    if (aContent == mRoot) {
+        // Check for a change to the 'ref' attribute on an atom, in which
+        // case we may need to nuke and rebuild the entire content model
+        // beneath the element.
+        if (aAttribute == nsXULAtoms::ref)
+            Rebuild();
+
+        // Check for a change to the 'datasources' attribute. If so, setup
+        // mDB by parsing the vew value and rebuild.
+        else if (aAttribute == nsXULAtoms::datasources) {
+            LoadDataSources(aDocument);
+            Rebuild();
+        }
+    }        
 }
 
 void
@@ -609,11 +655,9 @@ nsXULTemplateBuilder::OnEndUpdateBatch(nsIRDFDataSource* aDataSource)
 //
 
 nsresult
-nsXULTemplateBuilder::LoadDataSources()
+nsXULTemplateBuilder::LoadDataSources(nsIDocument* doc)
 {
     NS_PRECONDITION(mRoot != nsnull, "not initialized");
-    if (! mRoot)
-        return NS_ERROR_NOT_INITIALIZED;
 
     nsresult rv;
 
@@ -621,6 +665,10 @@ nsXULTemplateBuilder::LoadDataSources()
     if (mCache)
     	mCache = nsnull;
 
+    if (mDB) {
+        mDB->RemoveObserver(this);
+    }
+
     // create a database for the builder
     mDB = do_CreateInstance(NS_RDF_DATASOURCE_CONTRACTID_PREFIX "composite-datasource");
 
@@ -640,11 +688,6 @@ nsXULTemplateBuilder::LoadDataSources()
     if (allowneg == NS_LITERAL_STRING("false"))
 		mDB->SetAllowNegativeAssertions(PR_FALSE);
 
-    nsCOMPtr<nsIDocument> doc = mRoot->GetDocument();
-    NS_ASSERTION(doc, "element has no document");
-    if (! doc)
-        return NS_ERROR_UNEXPECTED;
-
     // Grab the doc's principal...
     nsIPrincipal *docPrincipal = doc->GetPrincipal();
     if (!docPrincipal)
@@ -768,9 +811,6 @@ nsXULTemplateBuilder::LoadDataSources()
     // Add ourselves as a datasource observer
     mDB->AddObserver(this);
 
-    // Add ourselves as a document observer
-    doc->AddObserver(this);
-
     return NS_OK;
 }
 

content/xul/templates/src/nsXULTemplateBuilder.h

@@ -240,7 +240,7 @@ public:
                    void* aClosure);
 
     nsresult
-    LoadDataSources();
+    LoadDataSources(nsIDocument* aDoc);
 
     nsresult
     InitHTMLTemplateRoot();