I want to change how a panel header is rendered. According to the documentation, I should be able to specify a tpl config. Unfortunately, the header class does not honor it and instead favors the private headingTpl property.
Steps to reproduce the problem:
Create a panel.
Give it a header config.
In the header config, provide a tpl config that prints "foo" before and after the title.
tpl is used for a different purpose. If you use the update method and pass in an object then the tpl config will work. headerTpl is used as the renderTpl for the title component. So tpl is on the Ext.panel.Header and headerTpl is used on the Ext.Component that is the title.