Is there anyway I can detect if an item is spawned from either a creative tab or /give command? I know that there's an onUpdate function for each item but I only need to call my code once when the item enters the player inventory.

Nope.

 

Even if catching ItemStack's creation would be applied to vanilla (there are quite few places to cover), it would be impossible to catch it for all mods.

 

What you can track is:

* Joining ItemStack to world (joining in any way like dropping, spawning, etc.)

* Change to Player's inventory (by checking last tick stacks with current ones)

 

As to catching levels of creation you mentioned:

1. For command you might be able to catch commands themselves.

2. For creative inventory I don't think so. (but maybe)

3. Mentioned "Change to Player's inventory" will be able to track anything "new", but it won't recognise source of added ItemStack.

 

Any particulat purpose? There might be some way around it.

Nope.

 

Even if catching ItemStack's creation would be applied to vanilla (there are quite few places to cover), it would be impossible to catch it for all mods.

 

What you can track is:

* Joining ItemStack to world (joining in any way like dropping, spawning, etc.)

* Change to Player's inventory (by checking last tick stacks with current ones)

 

As to catching levels of creation you mentioned:

1. For command you might be able to catch commands themselves.

2. For creative inventory I don't think so. (but maybe)

3. Mentioned "Change to Player's inventory" will be able to track anything "new", but it won't recognise source of added ItemStack.

 

Any particulat purpose? There might be some way around it.

I think ItemStack joining the world would do the trick. I need to initialize custom NBT data for the item when it is first created and I was able to do that with onCreated but that only includes crafting and smelting. If the item is spawned from creative mode and used, it crashes the game.

Then nope - you should not do it that way. You are looking in the wrong way, use standard Java techiques.

 

Use lazy inicialization technique.

Something like:

getStacksNBT()
{
    if (nbt null)
       setNBT(some new NBT);
    return theNBT;
}

If null-checking is not enough (you can have more than null or non-null cases) you can hold e.g boolean like "has been just created"

Then nope - you should not do it that way. You are looking in the wrong way, use standard Java techiques.

 

Use lazy inicialization technique.

Something like:

getStacksNBT()
{
    if (nbt null)
       setNBT(some new NBT);
    return theNBT;
}

If null-checking is not enough (you can have more than null or non-null cases) you can hold e.g boolean like "has been just created"

Thanks for your help. Now, the NBT won't get initialized unless the user actually uses the item which is more efficient.