I believe you were on the right track; however, getBlock() will return the block before the transformation. If we wait a tick, we can use the location of the getBlock() to get the new block.
code_language.skript:
on load:
import "org.bukkit.event.block.BlockFormEvent"
on "org.bukkit.event.block.BlockFormEvent" with priority 5:
wait 1 tick
broadcast "%block at block at location of event.getBlock()%"
This should return cobblestone when water and lava meet.
So you can do something like this:
code_language.skript:
on load:
import "org.bukkit.event.block.BlockFormEvent"
on "org.bukkit.event.block.BlockFormEvent" with priority 5:
wait 1 tick
block at event.getBlock() is cobblestone
chance of 100%:
set block at event.getBlock() to emerald ore
[doublepost=1501186991][/doublepost]It should also be know, during my testing, I believe the "on form" event is not broken- rather, it no longer supports an "of %blocktype%" argument. I say this because this also works:
code_language.skript:
on block form:
event-block is cobblestone
wait 1 ticks
chance of 100%:
set block at event-block to emerald ore