Do not send empty server requests (#11733)

Change-Id: Icacc102132ac4fbd8e00f97b3a752f2483cf3936

4 files changed, 79 insertions, 52 deletions

diff --git a/client/src/com/vaadin/client/ApplicationConnection.java b/client/src/com/vaadin/client/ApplicationConnection.java
index 1d6d09c262..51ab2120f6 100644
--- a/client/src/com/vaadin/client/ApplicationConnection.java
+++ b/client/src/com/vaadin/client/ApplicationConnection.java
@@ -2783,66 +2783,75 @@ public class ApplicationConnection implements HasHandlers {
     private void sendInvocationsToServer() {
         boolean showLoadingIndicator = false;
         JsonArray reqJson = Json.createArray();
-        if (!pendingInvocations.isEmpty()) {
-            if (ApplicationConfiguration.isDebugMode()) {
-                Util.logMethodInvocations(this, pendingInvocations.values());
+        if (pendingInvocations.isEmpty()) {
+            return;
+        }
+
+        if (ApplicationConfiguration.isDebugMode()) {
+            Util.logMethodInvocations(this, pendingInvocations.values());
+        }
+
+        for (MethodInvocation invocation : pendingInvocations.values()) {
+            String connectorId = invocation.getConnectorId();
+            if (!getConnectorMap().connectorExists(connectorId)) {
+                getLogger().info(
+                        "Not sending RPC for removed connector: " + connectorId
+                                + ": "
+                                + Util.getInvocationDebugString(invocation));
+                continue;
             }
 
-            for (MethodInvocation invocation : pendingInvocations.values()) {
-                String connectorId = invocation.getConnectorId();
-                if (!getConnectorMap().connectorExists(connectorId)) {
-                    getLogger()
-                            .info("Not sending RPC for removed connector: "
-                                    + connectorId + ": "
-                                    + Util.getInvocationDebugString(invocation));
-                    continue;
-                }
+            JsonArray invocationJson = Json.createArray();
+            invocationJson.set(0, connectorId);
+            invocationJson.set(1, invocation.getInterfaceName());
+            invocationJson.set(2, invocation.getMethodName());
+            JsonArray paramJson = Json.createArray();
 
-                JsonArray invocationJson = Json.createArray();
-                invocationJson.set(0, connectorId);
-                invocationJson.set(1, invocation.getInterfaceName());
-                invocationJson.set(2, invocation.getMethodName());
-                JsonArray paramJson = Json.createArray();
+            Type[] parameterTypes = null;
+            if (!isLegacyVariableChange(invocation)
+                    && !isJavascriptRpc(invocation)) {
+                try {
+                    Type type = new Type(invocation.getInterfaceName(), null);
+                    Method method = type.getMethod(invocation.getMethodName());
+                    parameterTypes = method.getParameterTypes();
 
-                Type[] parameterTypes = null;
-                if (!isLegacyVariableChange(invocation)
-                        && !isJavascriptRpc(invocation)) {
-                    try {
-                        Type type = new Type(invocation.getInterfaceName(),
-                                null);
-                        Method method = type.getMethod(invocation
-                                .getMethodName());
-                        parameterTypes = method.getParameterTypes();
-
-                        showLoadingIndicator |= !TypeDataStore
-                                .isNoLoadingIndicator(method);
-                    } catch (NoDataException e) {
-                        throw new RuntimeException("No type data for "
-                                + invocation.toString(), e);
-                    }
-                } else {
-                    // Always show loading indicator for legacy requests
-                    showLoadingIndicator = true;
+                    showLoadingIndicator |= !TypeDataStore
+                            .isNoLoadingIndicator(method);
+                } catch (NoDataException e) {
+                    throw new RuntimeException("No type data for "
+                            + invocation.toString(), e);
                 }
+            } else {
+                // Always show loading indicator for legacy requests
+                showLoadingIndicator = true;
+            }
 
-                for (int i = 0; i < invocation.getParameters().length; ++i) {
-                    // TODO non-static encoder?
-                    Type type = null;
-                    if (parameterTypes != null) {
-                        type = parameterTypes[i];
-                    }
-                    Object value = invocation.getParameters()[i];
-                    JsonValue jsonValue = JsonEncoder.encode(value, type, this);
-                    paramJson.set(i, jsonValue);
+            for (int i = 0; i < invocation.getParameters().length; ++i) {
+                // TODO non-static encoder?
+                Type type = null;
+                if (parameterTypes != null) {
+                    type = parameterTypes[i];
                 }
-                invocationJson.set(3, paramJson);
-                reqJson.set(reqJson.length(), invocationJson);
+                Object value = invocation.getParameters()[i];
+                JsonValue jsonValue = JsonEncoder.encode(value, type, this);
+                paramJson.set(i, jsonValue);
             }
+            invocationJson.set(3, paramJson);
+            reqJson.set(reqJson.length(), invocationJson);
+        }
+
+        pendingInvocations.clear();
+        // Keep tag string short
+        lastInvocationTag = 0;
+        sendServerRpcWhenConnectionAvailable = false;
 
-            pendingInvocations.clear();
-            // Keep tag string short
-            lastInvocationTag = 0;
-            sendServerRpcWhenConnectionAvailable = false;
+        if (reqJson.length() == 0) {
+            // Nothing to send, all invocations were filtered out (for
+            // non-existing connectors)
+            getLogger()
+                    .warning(
+                            "All RPCs filtered out, not sending anything to the server");
+            return;
         }
 
         String extraParams = "";
diff --git a/client/src/com/vaadin/client/ui/VUpload.java b/client/src/com/vaadin/client/ui/VUpload.java
index dff45a6951..2800acccf9 100644
--- a/client/src/com/vaadin/client/ui/VUpload.java
+++ b/client/src/com/vaadin/client/ui/VUpload.java
@@ -36,9 +36,12 @@ import com.google.gwt.user.client.ui.Panel;
 import com.google.gwt.user.client.ui.SimplePanel;
 import com.vaadin.client.ApplicationConnection;
 import com.vaadin.client.BrowserInfo;
+import com.vaadin.client.ConnectorMap;
 import com.vaadin.client.StyleConstants;
 import com.vaadin.client.VConsole;
+import com.vaadin.client.ui.upload.UploadConnector;
 import com.vaadin.client.ui.upload.UploadIFrameOnloadStrategy;
+import com.vaadin.shared.ui.upload.UploadServerRpc;
 
 /**
  * 
@@ -246,7 +249,9 @@ public class VUpload extends SimplePanel {
                             t.cancel();
                         }
                         VConsole.log("VUpload:Submit complete");
-                        client.sendPendingVariableChanges();
+                        ((UploadConnector) ConnectorMap.get(client)
+                                .getConnector(VUpload.this)).getRpcProxy(
+                                UploadServerRpc.class).poll();
                     }
 
                     rebuildPanel();
diff --git a/server/src/com/vaadin/ui/Upload.java b/server/src/com/vaadin/ui/Upload.java
index 693bd74dbf..2da7db53b5 100644
--- a/server/src/com/vaadin/ui/Upload.java
+++ b/server/src/com/vaadin/ui/Upload.java
@@ -121,6 +121,11 @@ public class Upload extends AbstractComponent implements Component.Focusable,
             public void change(String filename) {
                 fireEvent(new ChangeEvent(Upload.this, filename));
             }
+
+            @Override
+            public void poll() {
+                // Nothing to do, called only to visit the server
+            }
         });
     }
 
diff --git a/shared/src/com/vaadin/shared/ui/upload/UploadServerRpc.java b/shared/src/com/vaadin/shared/ui/upload/UploadServerRpc.java
index b576eb9114..b353057ab3 100644
--- a/shared/src/com/vaadin/shared/ui/upload/UploadServerRpc.java
+++ b/shared/src/com/vaadin/shared/ui/upload/UploadServerRpc.java
@@ -27,4 +27,12 @@ public interface UploadServerRpc extends ServerRpc {
      */
     void change(String filename);
 
+    /**
+     * Called to poll the server to see if any changes have been made e.g. when
+     * starting upload
+     * 
+     * @since
+     */
+    void poll();
+
 }