Addon or macro to make a button unclickable unless it has proc'd

[valkry]

If it's a spell that's not available until certain conditions are met {examples - Templar's Verdict can only be used with 3 holy power, Hammer of Wrath can't be used unless the target is 25% HP or less} you can just add it in as a priority or step and the game won't be able to cast it if it's not available.

For spells with a cast time that proc instant like Lava Burst and Mind Spike, you can use a stopcasting macro as a step or priority.

/stopcasting
/cast Lava burst

But as they say, "macros can't make decisions for you". You can't create a macro, addon or button that will only do X if Y buff/debuff/etc occurs.

I was going to mention the stopcasting, but that will activate the gcd won't it?

[Khatovar]

I was going to mention the stopcasting, but that will activate the gcd won't it?

From my understanding, anything that invokes a GCD should still invoke a GCD if it's called, regardless of if it completed casting, came up instant or not. I don't use stopcasting because it's erratic and impacts my white DPS since I run melee.

Luckily I only have one toon now that needs a way to deal with casttime spells that proc instant {Maelstrom Weapon on my Enh Shaman}, and I use Randomized Casting to deal with it. Not as ideal as when I manually dealt with it, but it's a more than fair tradeoff for not having to watch it all the time.