Dojo Toolkit - adding dijit inside dijit (ex. button into ContentPane in AccordionContainer) - dojo

Question

I'm learning Dojo Toolkit and I'm fighting with adding dijit into dijit. There was simmilar post about it but wih DIV's. I just simply want to programmatically insert a button or anything else to a ContentPane like this:
I have a script (with required items to insert button):
require(["dijit/layout/AccordionContainer", "dijit/layout/ContentPane", "dojo/domReady!", "dijit/form/Button", "dijit/_WidgetBase"],
function(AccordionContainer, ContentPane, Button){
var aContainer = new AccordionContainer({style:"height: 300px"}, "markup");
var aChild1 = new ContentPane({
title: "Date selectors",
content: "Test"
});
var aChild2 = new ContentPane({
title:"Group 2",
content:"Test"
});
var aChild3 = new ContentPane({
title:"Group 3",
content:"Test"
});
aContainer.addChild(aChild1);
aContainer.addChild(aChild2);
aContainer.addChild(aChild3);
aContainer.startup();
});
And my DIV is simply:
<div id="markup" style="width: 250px; height: 300px">
This ContentPane should work as left toolbar with rollable panes. In first one I'd like to add date pickers or button or anything else. Above code works until I try to add subChild. I tried to create var with button and make it child of a content pane like:
var btn as new Button([...]);
and place it here:
aContainer.addChild(aChild1);
aChild1.addChild(btn);
aContainer.addChild(aChild2);
aContainer.addChild(aChild3);
aContainer.startup();
but it not works. How can I build my layout in this case? Thanks in advance for help.

Answer 1

Problem solved. I applied declarative instead of programatic creation:
In script, I simply added this line:
require(["dojo/parser", "dijit/layout/ContentPane"]);
Then I wrote some divs like:
<div data-dojo-type="dijit/layout/ContentPane">
Some text
</div>
I found a tip (inside the code of demos) that:
content pane has no children so just use dojo's builtin after advice
dojo.connect(dijit.layout.ContentPane.prototype, "resize",
function(mb)
... so all I had to do was:
<div data-dojo-type="dijit.layout.ContentPane" data-dojo-props='selected:true, title:"Calendar"'>
<!-- calendar widget pane -->
<input id="calendar1" data-dojo-type="dijit.Calendar">
</div>
If you would like to see, how to place any of layout items in one place, see Dojo Theme Tester (view source):
https://download.dojotoolkit.org/release-1.7.0/dojo-release-1.7.0/dijit/themes/themeTester.html?theme=tundra
You will find every fragment well described. For me, it is more useful than documentation.
I hope that by solving my problem, this solution will be helpful to someone.