Preventing Lifelink

[(nameless one)]

Here's the scenario:

I am attacking with Wurmcoil Engine. My opponent blocks with Qasali Pridemage, then used its ability to destroy another artifact that I control. Does it work in a way that Wurmcoil Engine will not be dealing damage to Qasali Pridemage, which in return stops lifelink?

If this works, can anyone thoroughly explain?

[Tammit67]

Here's the scenario:

I am attacking with Wurmcoil Engine. My opponent blocks with Qasali Pridemage, then used its ability to destroy another artifact that I control. Does it work in a way that Wurmcoil Engine will not be dealing damage to Qasali Pridemage, which in return stops lifelink?

If this works, can anyone thoroughly explain?

Since when damage is assigned/dealt, the pridemage is no longer in play, damage cannot be dealt to it. Thus lifelink does not happen since wurmcoil has nothing to deal damage to in order to trigger lifelink (I realize lifelink no longer is a triggered event, but my vocab is only so big). If wurmcoil had trample, that would be a different story, as you could assign the rest of the damage to the defending player (or all if the sacrifice does occur).

If you are looking for a specific ruling, I'm sure I can find one.

TL;DR: Damage needs to be dealt for lifelink to happen. No damage dealt, no lifelink.