Make component.createObject require a parent argument

For graphical objects (the common case) a common mistake is to not
parent a dynamically created item. Since you almost always want to add a
parent, and it's hard for a beginner to diagnose this problem, a parent
is now a required argument and dealt with by the createObject function.

Task-number: QTBUG-10110

2 files changed, 3 insertions, 8 deletions

diff --git a/doc/src/snippets/declarative/componentCreation.js b/doc/src/snippets/declarative/componentCreation.js
index be928f0..f6fb379 100644
--- a/doc/src/snippets/declarative/componentCreation.js
+++ b/doc/src/snippets/declarative/componentCreation.js
@@ -4,11 +4,10 @@ var sprite;
 
 function finishCreation() {
     if (component.status == Component.Ready) {
-        sprite = component.createObject();
+        sprite = component.createObject(appWindow);
         if (sprite == null) {
             // Error Handling
         } else {
-            sprite.parent = appWindow;
             sprite.x = 100;
             sprite.y = 100;
             // ...
@@ -32,13 +31,12 @@ else
 
 //![2]
 component = Qt.createComponent("Sprite.qml");
-sprite = component.createObject();
+sprite = component.createObject(appWindow);
 
 if (sprite == null) {
     // Error Handling
     console.log("Error loading component:", component.errorsString());
 } else {
-    sprite.parent = appWindow;
     sprite.x = 100;
     sprite.y = 100;
     // ...
@@ -47,5 +45,3 @@ if (sprite == null) {
 
 }
 
-createSpriteObjects();
-
diff --git a/doc/src/snippets/declarative/dynamicObjects.qml b/doc/src/snippets/declarative/dynamicObjects.qml
index dd55d78..6a8c927 100644
--- a/doc/src/snippets/declarative/dynamicObjects.qml
+++ b/doc/src/snippets/declarative/dynamicObjects.qml
@@ -21,8 +21,7 @@ Rectangle {
     }
 
     function createRectangle() {
-        var object = rectComponent.createObject();
-        object.parent = rootItem;
+        var object = rectComponent.createObject(rootItem);
     } 
 
     Component.onCompleted: createRectangle()