Connecting Item to Entity problem

[Frostmourneee]

Hi. 
My goal was to create minecart very similar to Furnace_Minecart, but with small property differences, e.g. changing INGREDIENT.COAL to INGREDIENT.APPLE, nevermind.
On the first try I've created new class MinecartNew extends MinecartFurnace (which extends AbstractMinecart). So I've registered this new Entity, I have registered Renderer for it and in minecraft I had two practically equal minecart_furnace versions. Then I was able to change my vehicle speed by overriding "public float getMaxCartSpeedOnRail()". At that moment in minecraft I had vanilla minecart_furnace and my vehicle with greater speed and same textures as vanilla one.
But I have no idea how to change INGREDIENT.COAL to INGREDIENT.APPLE, because this field is private in MinecartFurnace. To avoid it I changed my new class "MinecartNew extends MinecartFurnace" to "MinecartNew extends AbstractMinecart", copy paste there everything which was in MinecartFurnace and now I can change INGREDIENT without any problem. I can /summon my new entity in minecraft now and I can change its properties as I want.

The problem is "how to create item which will be connected to my entity?". I do not want to type /summon to interact with my vehicle every time of course, I want to use item to do it. 
Well, I know how to create simple Block and connect it to my custom item, there is no issues. But how to create item and then connect it to entity... So that is my question. Thanks in advance!

//P.S. I've tried to look at the vanilla minecarts code and how do they connects to items and it works with special class MinecartItem which requires AbstractMinecart.Type and item.Properties. There is no issues with Item.Properties, but there is problem with AbstractMinecart.Type. Type can be FURNACE, HOPPER, TNT, etc. I can not create new Type, because it is "public static enum Type" in AbstractMinecart. And if I use FURNACE type then of course my item will be registered to vanilla furnace_minecart, not to my new minecart

//P.P.S If you know that my sequencing isn't right at all, may be my MinecartNew class should not extends AbstractMinecart or something like this - I'll be glad to receive your advises how to solve my problems

[Frostmourneee]

Damn, may be it's possible somehow to create item and add to it "if (right click with this item on to rails) then imitate /summon minecart_new" or smth like this? It sounds to me as possible and not dumb way to reach my goals... Could you please share your thoughts about it?) Maybe this is a good option?

[Draco18s]

Gosh, maybe there's a MinecartItem?

[Curle]

Tone down the condescending, Draco.

[Frostmourneee]

1 hour ago, Draco18s said:

Gosh, maybe there's a MinecartItem?

Well, tbh I do not understand what does it mean. Yeah, there is vanilla class MinecartItem and it is used to connect vanilla items to vanilla carts) All of these I've said in P.S.

It's impossible to use MinecartItem in my situation, because it requires AbstractMinecart.Type as the first parameter. If I type e.g. AbstractMinecart.Type.FURNACE then item which was registered via MinecartItem will be connected to vanilla furnace_minecrat, not my custom cart.

If I'm not right and you know the way to reach my goals using MinecartItem, could you please share this way?)

[Draco18s]

Why not replicate what it does?

Obviously not exactly, but I'm sure somewhere in it is the code that handles the right-click action and spawns an entity.

Edited December 1, 2021 by Draco18s