Cast only if not channelling

Is it possible to create a macro to cast a spell only if another spell is not channelling? Specifically cast arcane blast only if not channelling arcane missiles. I want to avoid wasting channelling spell by breaking it before it’s done channelling.

[nochanneling]

1 Like

Pins are your friend

1 Like

This kind of construction works differently and might fail sometimes.
NoChanneling switch works better.

Example?

10char