I want to make the player be able to attach a leash to a fence without a mob leashed to it.

So essentially have a fence persisting like this

However when I realod the world the leash knot is gone, and I don't understand why (I know it's a vanilla feature, but even looking at the entity code I can't find out why it breaks so I can override it).

What I've tried so far is to intercept the EntityLeaveLevelEvent, but that seems to not be firing when reloading the world and removing the entity.
So what is actually been fired when the lead disappear, so I can prevent it? Where should I look into?

HangingEntity.survives() ?

27 minutes ago, warjort said:

HangingEntity.survives() ?

That was the first method I've looked into, but doesn't seem to be called on world reload. Also the leash knot entity overrides the base method by simply checking the block is "knotted" to is a fence block, which in this case it is

Don't know then. Looks like a job for your debugger.

Unless what you are actually doing is just creating a ghost entity on the client?

I think I figured out what the problem is: the leash knot entity type has the noSave() attribute set
 

public static final EntityType<LeashFenceKnotEntity> LEASH_KNOT = register("leash_knot", EntityType.Builder.<LeashFenceKnotEntity>of(LeashFenceKnotEntity::new, MobCategory.MISC).noSave().sized(0.375F, 0.5F).clientTrackingRange(10).updateInterval(Integer.MAX_VALUE));

What I've tried is to create a custom entity that extends the LeashFenceKnotEntity class and when registering it I removed the noSave attribute, and sure enough it worked: the leash stayed through world reloads.
But that raises another question: can I remove this attribute from the vanilla entity? Since having to create a custom entity imply that I have to replace all vanilla leash knots with custom ones when they are added (which is not optimal I guess)