[Trinidad] how to know that PPR is ongoing

[Renzo Tomaselli]

Hi, assume to have a component which might be rendered either in a full 
page or in a PPR context.
It needs to distinguish these alternatives since it might run some js 
chunck requiring full DOM completion.
For example, on IE we are not allowed to modify the DOM before page 
completion, thus we must delay by means of onLoad handling.
How do we know "officially" from js that we are in a PPR ?
Suggestions are welcome.