ExtJS accordion init component while collapsed

I have following problem in EXTJS: I have an accordion layout with 2 panels. the first panel is for choosing an element and if you doubleclick the detail will be displayed in the second panel.

However there is one problem: The elements of panel2 seems not to be initialised, so i get an "is undefined" error.

When i open panel2 and close it, i dont have the problem. However opening and closing it looks creepy.

Is there a way to initialise the elements while it is co开发者_高级运维llapsed? or is there something like a callback in mainPanel.layout.setActiveItem(panel1)...callback:initPanel2() ?

---

Both panels should already be rendered (unless you have set deferredRender: true) so it's unclear exactly what you are trying to do. What does your code look like?