hope the following two tips are of help: 1 ) that sounds like a null pointer exception (natively). you are trying to invoke a native field of a null value
2 ) removing all childrens iterating through them can be very tricky. See a correct way of doing it manually : https://code.google.com/p/gwtjsutil/source/browse/trunk/gwtjsutil/src/org/sgx/jsutil/client/DOMUtil.java#72 : while(e.getLastChild()!=null) e.removeChild(e.getLastChild()); good luck On Sunday, February 17, 2013 6:56:19 PM UTC-2, Ed wrote: > > When I override the method SimplePanel.clear() to remove all elements of > the contained element in SimplePanel, and then add a widget > throug setWidget() I receive the error (see the complete error below: > --- > this.appendChild is not a function"? > ---- > > I remove all element after SimplePanel performs a clear itself such that > it removed the contained widget, something like (subclass of SimplePanel: > ---- > public final void clear() { > super.clear(); > UtilsWidget.removeAllChilds(getElement()); > } > } > --- > I remove all child elements by iterating through all children (in reversed > order) and removing them when the child is of type Element. > When I not remove all children, all is fine, but then the added extra > elements aren't removed :( > > > Why is this? > I perform this step as I also add "lightweight" text elements to the > SimplePanel that I also want to be removed. > > > > The exact exception (using gwt 2.5.0): > ----- > com.google.gwt.core.client.JavaScriptException: (TypeError) > @com.google.gwt.core.client.impl.Impl::apply(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)([JavaScript > > object(2812), JavaScript object(1793), JavaScript object(2822)]): > this.appendChild is not a function > com.bv.gwt.common.exception.ExceptionHandlerDefault - - Handling an > exception. Exception: com.google.gwt.core.client.JavaScriptException: > (TypeError) > @com.google.gwt.core.client.impl.Impl::apply(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)([JavaScript > > object(2812), JavaScript object(1793), JavaScript object(2822)]): > this.appendChild is not a function > at > com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:249) > at > com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136) > at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:571) > at > com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:279) > at > com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91) > at com.google.gwt.core.client.impl.Impl.apply(Impl.java) > at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:242) > at sun.reflect.GeneratedMethodAccessor39.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103) > at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71) > at > com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172) > at > com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:293) > at > com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:547) > at > com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:364) > at java.lang.Thread.run(Thread.java:662) > > > -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/google-web-toolkit?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
