Do not throw exception when trying to bind a preinitialized instance field (#7749)

Change-Id: I8b40e667d03b63e05f006e7cedf108345591d118

2 files changed, 13 insertions, 11 deletions

diff --git a/server/src/com/vaadin/ui/declarative/DesignContext.java b/server/src/com/vaadin/ui/declarative/DesignContext.java
index 25765611aa..0ce269261b 100644
--- a/server/src/com/vaadin/ui/declarative/DesignContext.java
+++ b/server/src/com/vaadin/ui/declarative/DesignContext.java
@@ -437,11 +437,12 @@ public class DesignContext implements Serializable {
      * at the given component. Also registers the componentid, localId and
      * caption of the given component and all its children to the context
      * 
-     * 
      * @param component
      *            The component to be synchronized from design
      * @param componentDesign
      *            The html tree node containing the description of the component
+     * @throws DesignException
+     *             if the design contains duplicate local or global ids
      */
     public void synchronizeAndRegister(Component component,
             Element componentDesign) {
@@ -463,7 +464,11 @@ public class DesignContext implements Serializable {
         // from the attributes of componentDesign
         if (attributes.hasKey(LOCAL_ID_ATTRIBUTE)) {
             String localId = attributes.get(LOCAL_ID_ATTRIBUTE);
-            mapLocalId(localId, component); // two-way map
+            boolean mappingExists = mapLocalId(localId, component);
+            if (mappingExists) {
+                throw new DesignException(
+                        "the following local id is not unique: " + localId);
+            }
         }
         // caption: a property of a component, possibly not unique
         String caption = component.getCaption();
diff --git a/server/src/com/vaadin/ui/declarative/FieldBinder.java b/server/src/com/vaadin/ui/declarative/FieldBinder.java
index af82d9c58c..fcc78db414 100644
--- a/server/src/com/vaadin/ui/declarative/FieldBinder.java
+++ b/server/src/com/vaadin/ui/declarative/FieldBinder.java
@@ -135,8 +135,6 @@ public class FieldBinder implements Serializable {
     /**
      * Tries to bind the given {@link Component} instance to a member field of
      * the bind target. The fields are matched based on localId, id and caption.
-     * If a field is already bound (not null), {@link FieldBindingException} is
-     * thrown.
      * 
      * @param instance
      *            the instance to be bound to a field
@@ -197,14 +195,13 @@ public class FieldBinder implements Serializable {
             Object fieldValue = ReflectTools.getJavaFieldValue(bindTarget,
                     field);
             if (fieldValue != null) {
-                getLogger().severe(
-                        "The field with identifier \"" + identifier
-                                + "\" already mapped");
-                throw new FieldBindingException(
-                        "Duplicate identifier found for a field: " + fieldName);
+                getLogger().fine(
+                        "The field \"" + fieldName
+                                + "\" was already mapped. Ignoring.");
+            } else {
+                // set the field value
+                ReflectTools.setJavaFieldValue(bindTarget, field, instance);
             }
-            // set the field value
-            ReflectTools.setJavaFieldValue(bindTarget, field, instance);
             return true;
         } catch (IllegalAccessException e) {
             throw new FieldBindingException("Field binding failed", e);