Without looking deeply into the stack trace I would guess the problem is mixing Jewel elements with MX containers. There is code in the MX package that assumes components are UIComponents and as Jewel components are not, errors are not surprising.
My suggestion is to either stick to one of components set (either MX or Jewel) or at least wrap Jewel components in MX containers (haven’t tried that). So in your case either replace <j:Label> with <mx:Label> or do <mx:Container><j:Label/></mx:Container> Hope this works for you. From: tranquiliste<mailto:[email protected]> Sent: Thursday, July 9, 2020 5:43 PM To: [email protected]<mailto:[email protected]> Subject: Bug with Box ? error =>TypeError: child is null BoxLayout.js:77:9 Hello all, I have an error with Box which I don't know how to correct and I wonder if it's a bug I have reproduced the issue in a simple code as followed *TextBinding.mxml* <?xml version="1.0" encoding="utf-8"?> <j:Application xmlns:fx="http://ns.adobe.com/mxml/2009"; xmlns:ecrans="ecrans.*" xmlns:j="library://ns.apache.org/royale/jewel" xmlns:js="library://ns.apache.org/royale/basic" xmlns:html="library://ns.apache.org/royale/html" xmlns:mx="library://ns.apache.org/royale/mx" width="100%" height="100%"> <j:initialView> <j:View id="EcranBox" width="100%" height="100%"> <ecrans:Ecran2 id="Ecran2" /> </j:View> </j:initialView> </j:Application> *Ecran2Class.as* which extends Box package ecrans { import mx.containers.Box; public class Ecran2Class extends Box { // Constructeur public function Ecran2Class() { } } } *Ecran2.mxml* which only displays a label <?xml version="1.0" encoding="utf-8"?> <ecrans:Ecran2Class xmlns:fx="http://ns.adobe.com/mxml/2009"; xmlns:ecrans = "ecrans.*" xmlns:j="library://ns.apache.org/royale/jewel" xmlns:html="library://ns.apache.org/royale/html" xmlns:js="library://ns.apache.org/royale/basic" xmlns:mx="library://ns.apache.org/royale/mx" width="100%" > <fx:Script> </fx:Script> <j:Label text="Name :" /> </ecrans:Ecran2Class> In that configuration I get an error in the console: /child is null BoxLayout.js 77:9/ with the following stack measure file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/mx/containers/beads/BoxLayout.js:77 updateDisplayList file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/mx/containers/beads/BoxLayout.js:149 layout file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/mx/containers/beads/BoxLayout.js:115 performLayout file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/core/LayoutBase.js:251 handleInitComplete file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/core/LayoutBase.js:173 fireListeners file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/events/EventDispatcher.js:117 dispatchEventInternal_ file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/library/closure/goog/events/eventtarget.js:382 dispatchEvent file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/events/EventDispatcher.js:80 dispatchEvent file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/core/ElementWrapper.js:243 addedToParent file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/mx/core/Container.js:166 addedToParent file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/mx/containers/Box.js:71 addElement file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/core/UIBase.js:405 addElement file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/core/GroupBase.js:165 initializeStrandBasedObject file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/utils/MXMLDataInterpreter.js:241 generateMXMLArray file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/utils/MXMLDataInterpreter.js:127 generateMXMLInstances file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/utils/MXMLDataInterpreter.js:271 addedToParent file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/jewel/View.js:69 addElement file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/jewel/Application.js:144 initialize file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/jewel/Application.js:295 start file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/org/apache/royale/jewel/Application.js:264 <anonymous> file:///Users/nicolasA/Documents/dev/ApacheRoyale/TestBinding/bin/js-debug/TestBinding.html:253 Behaviour is the same if I extends Ecran2Class with HBox, VBox but it works with Panel *Important note if I change the jewel Label (<j:Label>) in a MX Label (<mx:Label>), it works* Thanks Nicolas ----- Nicolas -- Sent from: http://apache-royale-users.20374.n8.nabble.com/
