From 9cf3566409ab957139fd6cff2d9b3ea850dab7d1 Mon Sep 17 00:00:00 2001
From: apanizo <adolfo.panizo@gmail.com>
Date: Tue, 26 May 2015 14:03:20 +0200
Subject: [PATCH] When doing data binding over a list attribute, return an
 empty list or null accordingly.

---
 .../gwt/query/vm/JsonBuilderHandler.java      |  8 +++-
 .../client/dbinding/DataBindingTestJre.java   | 42 ++++++++++++++++++-
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/gwtquery-core/src/main/java/com/google/gwt/query/vm/JsonBuilderHandler.java b/gwtquery-core/src/main/java/com/google/gwt/query/vm/JsonBuilderHandler.java
index adbdd233..395a38a3 100644
--- a/gwtquery-core/src/main/java/com/google/gwt/query/vm/JsonBuilderHandler.java
+++ b/gwtquery-core/src/main/java/com/google/gwt/query/vm/JsonBuilderHandler.java
@@ -29,6 +29,7 @@ import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.Hashtable;
@@ -66,11 +67,16 @@ public class JsonBuilderHandler implements InvocationHandler {
 
   @SuppressWarnings("unchecked")
   private <T> Object jsonArrayToList(JsonArray j, Class<T> ctype, boolean isArray) {
+    if (j == null) {
+      return null;
+    }
+    
     List<T> l = new ArrayList<T>();
     for (int i = 0; j != null && i < j.length(); i++) {
       l.add((T) getValue(j, i, null, null, ctype, null));
     }
-    return l.isEmpty() ? null : isArray ? l.toArray((T[]) Array.newInstance(ctype, l.size())) : l;
+    
+    return l.isEmpty() ? Collections.emptyList() : isArray ? l.toArray((T[]) Array.newInstance(ctype, l.size())) : l;
   }
 
   private Double toDouble(String attr, JsonArray arr, int idx, JsonObject obj) {
diff --git a/gwtquery-core/src/test/java/com/google/gwt/query/client/dbinding/DataBindingTestJre.java b/gwtquery-core/src/test/java/com/google/gwt/query/client/dbinding/DataBindingTestJre.java
index 50123b80..f276f034 100644
--- a/gwtquery-core/src/test/java/com/google/gwt/query/client/dbinding/DataBindingTestJre.java
+++ b/gwtquery-core/src/test/java/com/google/gwt/query/client/dbinding/DataBindingTestJre.java
@@ -26,6 +26,7 @@ import com.google.gwt.query.client.builders.JsonBuilder;
 import com.google.gwt.query.client.builders.Name;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
@@ -165,6 +166,7 @@ public class DataBindingTestJre extends GWTTestCase {
     
     int getAge();
     String getName();
+    List<String> getPhones();
     GAddress address();
   }
 
@@ -173,9 +175,13 @@ public class DataBindingTestJre extends GWTTestCase {
                                                  + "   'email': 'foo@bar.com', "
                                                  + "   'age': 27, "
                                                  + "   'name': 'Foo Bar', "
+                                                 + "   'phones': [ "
+                                                 + "      '9166566',"
+                                                 + "      '65443333'"
+                                                 + "    ],"
                                                  + "   'address': {"
                                                  + "      'street': 'Street Foo N6', "
-                                                 + "      'phone': '670'"
+                                                 + "      'number': '670'"
                                                  + "   }"
                                                  + "}";
 
@@ -189,7 +195,7 @@ public class DataBindingTestJre extends GWTTestCase {
     assertEquals("Foo Bar", entity.getName());
     assertNotNull(entity.address());
     assertEquals("Street Foo N6", entity.address().street());
-    assertNotNull(entity.address().get("phone"));
+    assertNotNull(entity.address().get("number"));
   }
 
   // Nested strict not implemented in JS
@@ -211,4 +217,36 @@ public class DataBindingTestJre extends GWTTestCase {
       assertNull(entity.address().get("phone"));
     }
   }
+  
+  public void test_return_empty_list_when_array_isEmpty() {
+    //GIVEN a JSON representation of a user without phones
+    GUser user = GQ.create(GUser.class);
+    user.set("email", "a@b.com");
+    user.set("name", "Random Name");
+    user.set("phones", Collections.emptyList());
+    String json = user.toJson();
+    
+    //WHEN fetching that user
+    GUser retrievedUser = GQ.create(GUser.class);
+    retrievedUser.parse(json, true);
+    
+    //THEN
+    assertEquals(0, retrievedUser.getPhones().size());
+  }
+  
+  public void test_return_null_when_list_is_not_specified() {
+    //GIVEN a JSON representation of a user
+    GUser user = GQ.create(GUser.class);
+    user.set("email", "a@b.com");
+    user.set("name", "Random Name");
+    String json = user.toJson();
+    
+    //WHEN fetching that user
+    GUser retrievedUser = GQ.create(GUser.class);
+    retrievedUser.parse(json, true);
+    
+    //THEN
+    List<String> phones = retrievedUser.getPhones(); 
+    assertNull(phones);
+  }
 }
\ No newline at end of file
-- 
2.39.5