So, I'm writing a little tweak mod for my modpack.

I'm trying to increase the harvest level for iron ore to require an iron pickaxe (it makes sense trust me) and after a quick google search I found several code examples doing similar things using the Block.setHarvestLevel method, so I decided to try that.

 

Here's my code so far:

package com.ax1m.aximtweaks;

import net.minecraft.init.Blocks;
import cpw.mods.fml.common.Mod;
import cpw.mods.fml.common.Mod.EventHandler;
import cpw.mods.fml.common.event.FMLPostInitializationEvent;

@Mod(modid = AximTweaks.MODID, version = AximTweaks.VERSION)
public class AximTweaks
{
    public static final String MODID = "AximTweaks";
    public static final String VERSION = "0.0";
    
    @EventHandler
    public void init(FMLPostInitializationEvent event)
    {
        System.out.println("Increasing iron ore harvest level");
        Blocks.iron_ore.setHarvestLevel("pickaxe", 2);
    }
}

 

And here is the log from starting the thing.

As you can see it printed the log message I put in the code, however when I try it in game, a stone pickaxe will still harvest iron ore just fine. What went wrong here?

 

setHarvestLevel on vanilla stuff will not do what you are expecting. you will need to use events for that. (in case I missed a patch that changed that please correct me)

 

https://github.com/Failender/AdvancedTools/blob/master/main/java/de/failender/advancedtools/utils/ToolHandler.java

Thanks for your input! May I ask which forge version that code is written for? I'm using 1558 and I'm getting an import error on the last line of imports, and then it can't resolve the .state variable for both HarvestDropsEvent and BreakSpeed

thats 1.8 code, (1.8 introduced IBlockState) but it should be easy to rewrite it for 1.7

okay so bear with me, I think I managed to do it for BreakSpeed by changing it to speed.block, but it looks like HarvestDropEvent doesn't pass the block as a variable at all, only an ArrayList of ItemStacks that are about to drop. Problem is I don't know how to compare two ItemStacks, ItemStack.iron_ore doesn't seem to be the correct way... I tried looking at the ItemStack class but that's just a bit too daunting for right now.

if(stack.getItem()==Items.iron) itsIron();

and im pretty sure that 1.7 will have a reference of the block that got broken..

aaaaaaaand I found it. its HarvestDropsEvent#block

well, derpy me, don't know how I overlooked that ^^

thanks again for your help, I got it all working as intended now 

if(stack.getItem()==Items.iron) itsIron();

 

Note that this is an iron bar.  Checking for a block is a tad bit more complicated.

 

You have to reference

Blocks.iron_ore

and use ...

Item.getItemFromBlock()

IIRC to convert it to the item form (that's the method name, I just forget if it is a static method on Item, Items, Block, or Blocks).

I'm running into a weird new issue now. The mod works fine when I launch it in IDEA, but when I build the jar and run it in a modpack (I tested both my full pack as well as a barebones testpack with just NEI, minetweaker and a couple core-mods) it crashes as soon as I start breaking a block:

 

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 2/6/16 8:48 AM
Description: Unexpected error

java.lang.NoSuchFieldError: iron_ore
at com.ax1m.aximtweaks.HarvestLevelNerf.breakSpeed(HarvestLevelNerf.java:44)
at cpw.mods.fml.common.eventhandler.ASMEventHandler_26_HarvestLevelNerf_breakSpeed_BreakSpeed.invoke(.dynamic)
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:54)
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:140)
at net.minecraftforge.event.ForgeEventFactory.getBreakSpeed(ForgeEventFactory.java:89)
at net.minecraft.entity.player.EntityPlayer.getBreakSpeed(EntityPlayer.java:855)
at net.minecraftforge.common.ForgeHooks.blockStrength(ForgeHooks.java:138)
at net.minecraft.block.Block.func_149737_a(Block.java:643)
at net.minecraft.client.multiplayer.PlayerControllerMP.func_78743_b(PlayerControllerMP.java:177)
at net.minecraft.client.Minecraft.func_147116_af(Minecraft.java:1409)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1948)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:973)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:898)
at net.minecraft.client.main.Main.main(SourceFile:148)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

Click for full crash report

 

This is a snippet with the line the error refers to:

    public void breakSpeed(PlayerEvent.BreakSpeed speed) {
        boolean isIron, isDiamond;
        isIron = speed.block==Blocks.iron_ore;
        isDiamond = speed.block==Blocks.diamond_ore;
        if(isIron) {

 

What's the issue here? Did I do something wrong in building the jar?

You need to build your mod using the

build

Gradle task (either from the command line or IDEA's Gradle widow) so ForgeGradle reobfuscates your mod, replacing all method/field names with their equivalent SRG names (e.g.

func_0002_a

,

field_0003_c

).

I see, thanks that fixed the issue. So what's the purpose of the jar task then? That's the one I was using to build a jar before

The

jar

task builds a deobfuscated JAR, which can be used in the development environment of another mod (1.8.9 can load obfuscated mods in the development environment, so it's not as necessary any more).