How to change the orientation of the existing pages of the pdf report in the afterRender function in jsreport?

Question

How to change the orientation of the existing page(s) of the pdf report in the afterRender function? Is it possible to do so based on some selectors that we can add in the report template?

I have tried using two different kinds of templates - one is of type portrait

portrait template config

and

another type landscape

landscape template config

and merging them in the pdf utils.

But, is there any way to have one portrait template only and change the orientation of the selective pages programmatically?