Add selective data write support to AbstractSelect (#17148)

Change-Id: I06f82fe05f3b370af85538c0a85f2e60ee28d72d

2 files changed, 109 insertions, 0 deletions

diff --git a/server/src/com/vaadin/ui/declarative/DesignContext.java b/server/src/com/vaadin/ui/declarative/DesignContext.java
index f991b3013a..54be5dcea3 100644
--- a/server/src/com/vaadin/ui/declarative/DesignContext.java
+++ b/server/src/com/vaadin/ui/declarative/DesignContext.java
@@ -75,6 +75,8 @@ public class DesignContext implements Serializable {
     // component creation listeners
     private List<ComponentCreationListener> listeners = new ArrayList<ComponentCreationListener>();
 
+    private ShouldWriteDataDelegate shouldWriteDataDelegate = ShouldWriteDataDelegate.DEFAULT;
+
     public DesignContext(Document doc) {
         this.doc = doc;
         // Initialize the mapping between prefixes and package names.
@@ -661,4 +663,56 @@ public class DesignContext implements Serializable {
 
         return true;
     }
+
+    /**
+     * Determines whether the container data of a component should be written
+     * out by delegating to a {@link ShouldWriteDataDelegate}. The default
+     * delegate assumes that all component data is provided by a data source
+     * connected to a back end system and that the data should thus not be
+     * written.
+     * 
+     * @since
+     * @see #setShouldWriteDataDelegate(ShouldWriteDataDelegate)
+     * @param component
+     *            the component to check
+     * @return <code>true</code> if container data should be written out for the
+     *         provided component; otherwise <code>false</code>.
+     */
+    public boolean shouldWriteData(Component component) {
+        return getShouldWriteDataDelegate().shouldWriteData(component);
+    }
+
+    /**
+     * Sets the delegate that determines whether the container data of a
+     * component should be written out.
+     * 
+     * @since
+     * @see #shouldWriteChildren(Component, Component)
+     * @see #getShouldWriteDataDelegate()
+     * @param shouldWriteDataDelegate
+     *            the delegate to set, not <code>null</code>
+     * @throws IllegalArgumentException
+     *             if the provided delegate is <code>null</code>
+     */
+    public void setShouldWriteDataDelegate(
+            ShouldWriteDataDelegate shouldWriteDataDelegate) {
+        if (shouldWriteDataDelegate == null) {
+            throw new IllegalArgumentException("Delegate cannot be null");
+        }
+        this.shouldWriteDataDelegate = shouldWriteDataDelegate;
+    }
+
+    /**
+     * Gets the delegate that determines whether the container data of a
+     * component should be written out.
+     * 
+     * @since
+     * @see #setShouldWriteDataDelegate(ShouldWriteDataDelegate)
+     * @see #shouldWriteChildren(Component, Component)
+     * @return the shouldWriteDataDelegate the currently use delegate
+     */
+    public ShouldWriteDataDelegate getShouldWriteDataDelegate() {
+        return shouldWriteDataDelegate;
+    }
+
 }
diff --git a/server/src/com/vaadin/ui/declarative/ShouldWriteDataDelegate.java b/server/src/com/vaadin/ui/declarative/ShouldWriteDataDelegate.java
new file mode 100644
index 0000000000..29a78e1db6
--- /dev/null
+++ b/server/src/com/vaadin/ui/declarative/ShouldWriteDataDelegate.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.ui.declarative;
+
+import java.io.Serializable;
+
+import com.vaadin.ui.Component;
+
+/**
+ * Delegate used by {@link DesignContext} to determine whether container data
+ * should be written out for a component.
+ * 
+ * @see DesignContext#shouldWriteData(Component)
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public interface ShouldWriteDataDelegate extends Serializable {
+
+    /**
+     * The default delegate implementation that assumes that all component data
+     * is provided by a data source connected to a back end system and that the
+     * data should thus not be written.
+     */
+    public static final ShouldWriteDataDelegate DEFAULT = new ShouldWriteDataDelegate() {
+        @Override
+        public boolean shouldWriteData(Component component) {
+            return false;
+        }
+    };
+
+    /**
+     * Determines whether the container data of a component should be written
+     * out.
+     * 
+     * @param component
+     *            the component to check
+     * @return <code>true</code> if container data should be written out for the
+     *         provided component; otherwise <code>false</code>.
+     */
+    boolean shouldWriteData(Component component);
+}