Dynamic composition size for a template?

[mortoray]

Is it possible to make the composition size dynamic, based on the properties of the essential graphics template?

I have an animated title card that can be placed anywhere on the screen, and it's size depends on the size of the font the user chooses. The composition is currently oversized, to allow for larger text. It'd be nice if I could set the size of it based on the actual contents, based on the properties the user selects.

[Joost van der Hoeven · Accepted solution]

Composition sizes are fixed. There is no way to change the comp size with an expression. What you could so working in an oversized comp is a good practice. Inside de final comp, you could use an aexpession to scale your graphics to the final comp size. Or, in Pr, you could instruct to use the scale to frame size or set to frame size options. 

[mortoray]

I'm not clear on what you mean with scaling to the final comp size. Doesn't having the size changed in the final comp stretch the nested composition? Is there some way I can cause it not to stretch and instead scale via expressions?

[Mylenium]

It will always stretch and interpolate, of course. What you expect simply can't be done beyond the limited compensation that enabling continuous rasterization/ collapsing transformations for pre-comps will manage.

Mylenium