contentDidMount is triggered at a different time than onLoad.

[Mrcxt]

I have a situation where I need to dynamically calculate the height of an iframe after it has loaded. However, I found in the source code that contentDidMount is triggered before the srcDoc has finished loading, resulting in incorrect height calculation because the css and js have not finished loading at that time.

[ryanseddon]

Can you create a test case showing the problem