Create custom potion effect type in 1.12.2

Hello, i would like to know if its possible to create a custom potion effect type.
I already tried to register a new PotionEffectTypeWrapper with the method in the class PotionEffectType, but when i add the potion effect to the potion that doesnt work, the potion effect is not displayed in potion description.
Thanks

 

I would try something like make a custom bottle with custom name, use maybe PlayerInteractEvent and check for your custom bottle and apply your effect.

I hope this helps, its not much (I know) but its a start

 

I think PlayerItemConsumeEvent would be better.
"This event will fire when a player is finishing consuming an item (food, potion, milk bucket).
If the ItemStack is modified the server will use the effects of the new item and not remove the original one from the player's inventory.
If the event is cancelled the effect will not be applied and the item will not be removed from the player's inventory."

 

With the event, I didn't do any research on what to use...
And you can cancel the event and remove the item from the player

Code:

@EventHandler
public void event(PlayerItemConsumeEvent  e) {
    if (e.getItem().equals(/*your custom bottle*/)) {
        e.setCancelled(true);
        player.getInventory().getItemInMainHand().setType(Material.GLASS_BOTTLE);
        //your custom effect
    }
}

maybe this will work

 

Thats a good idea but i want the potion show my effect in description like other potion effect

Screenshot (open) Screenshot (close)

I told you i tried to register custom potion effect, here is the code

CustomPotionEffectType (open) CustomPotionEffectType (close)

Code:

public class CustomPotionEffectType {

    public static final PotionEffectType RAGE = new Rage(28);

    private static List<PotionEffectType> effects = new ArrayList<>();

    public CustomPotionEffectType() {
        try {
            /**
             * Access to the array byId who contains normal potion effects
             */
            Field field = PotionEffectType.class.getDeclaredField("byId");
            field.setAccessible(true);

            Field modifiersField = Field.class.getDeclaredField("modifiers");
            modifiersField.setAccessible(true);
            modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);


            /**
             * Check if the array byId isn't resized
             */
            if(((PotionEffectType[]) field.get(null)).length == 28) {


                /**
                 * If he isn't, add all custom effect (that we created), in our List
                 */
                for(Field f : CustomPotionEffectType.class.getDeclaredFields()) {
                    if(f.getType() == PotionEffectType.class) {
                        PotionEffectType effectType = (PotionEffectType) f.get(null);

                        effects.add(effectType);
                    }
                }


                /**
                 * Calculate the new array size and create new array with the new array size
                 */
                int arraySize = 28 + effects.size();

                PotionEffectType[] customEffectTypes = new PotionEffectType[arraySize];


                /**
                 * Add all normal effects to our new array
                 */
                PotionEffectType[] effectTypes = (PotionEffectType[]) field.get(null);
                for(int i=0;i<28;i++) {
                    customEffectTypes[i] = effectTypes[i];
                }


                /**
                 * redefine the variable byId with our new array
                 */
                field.set(null, customEffectTypes);


                /**
                 * Check if the variable byId is resized
                 */
                System.out.println("byId size : " + ((PotionEffectType[]) field.get(null)).length);


                /**
                 * Accessing to the boolean and set him to true
                 */
                field = PotionEffectType.class.getDeclaredField("acceptingNew");
                field.setAccessible(true);

                field.set(null, true);


                /**
                 * Register our custom effects
                 */
                for(PotionEffectType effectType : effects) {
                    PotionEffectType.registerPotionEffectType(effectType);

                    //noinspection deprecation
                    System.out.println(effectType + "("+effectType.getId()+") registered");
                }
            }

        } catch (NoSuchFieldException | IllegalAccessException e) {
            e.printStackTrace();
        }
    }



    public static List<PotionEffectType> getActiveCustomEffects(LivingEntity entity) {
        List<PotionEffectType> l = new ArrayList<>();

        for(PotionEffect potionEffect : entity.getActivePotionEffects()) {
            if(effects.contains(potionEffect.getType())) {
                l.add(potionEffect.getType());
            }
        }

        return l;
    }

}

the operation work but when i add the custom potion effect to potion nothing is happening


EDIT : I tried do dirrectly add the potion effect to player but the server crash

 

BUMP

 

nobody ?

 

Why not set a lore on the item?

 

Like waht RarimKL said, add lore

Code:

ItemStack customPotion = new ItemStack(Material.POTION);
ItemMeta im = customPotion.getItemMeta();
im.setLore(Arrays.asList("your", "effect", "description", "here"));
customPotion.setItemMeta(im);
//some example
ShapedRecipe recipe = new ShapedRecipe(customPotion);
recipe.shape("abc", "def", "ghi");
recipe.setIngredient('a', Material.DIAMOND);
recipe.setIngredient('b', "some other");
recipe.setIngredient('c', "you get the idea...")
getServer().addRecipe(recipe);

you can save your itemStack to check with the item used in the event

This is a recipe for in a crafting table. If you want to use it for brewingstand I don't know, but the internet does