Replacing a single method of a vanilla class

[chrixian]

First-- Thank you for looking at the thread... any help is appreciated.

 

I'm using Forge 9.10.0.786 and Mincraft 1.6.2. My end goal is to replace the drawItemStackTooltip method of the GuiContainer class.

 

I initially started by simply editing the GuiContainer file directly and now that I have it doing what I want I'm trying to figure out how I would go about implementing my changes to a fresh Forge install without modifying the original GuiContainer source directly.

 

All signs seem to point to having to use ASM, specifically implementing IFMLLoadingPlugin and IClassTransformer; however when I create a class that extends DummyModContainer and create classes that implement IFMLLoadingPlugin & IClassTransformer, when I hit the debug button to run the client there is no message in the console that FML or Forge has seen/recognized my classes and/or done anything with them.

 

When I create a class and annotate it with @Mod() etc as per the usual way I'd create a mod, it works as expected when I hit the debug button... Am I missing something special that has to be done from the deobfuscated environment ran from the IDE to use IFMLLoadingPlugin and IClassTransformer? Can I do class transformation from the FMLPreInitializationEvent or that not possible? Or perhaps there is a way to do what I want without IClassTransformer?

 

As I said, any insight/direction/correction/guidance/help is greatly appreciated.

[Mew]

Use this tutorial: http://www.minecraftforge.net/wiki/Using_Access_Transformers

 

That covers the basics. If you know what you are doing then you can go from there

[chrixian]

Use this tutorial: http://www.minecraftforge.net/wiki/Using_Access_Transformers

 

That covers the basics. If you know what you are doing then you can go from there

 

According to that tutorial I do indeed have to compile and reobfuscate and drop the jar in the coremod or mod folder etc etc to have it work... bleh. So I guess that's that? Seems so strange that there is no way to transform classes on the fly within the development environment.. frustrating.. okay thanks for pointing me to that tutorial I'll read it thoroughly just to try to absorb anything more.

 

[Mew]

Your welcome mate

[Mew]

I have now found that my CoreMod aint loading... Why would this be? I have everything I need

 

[hidden]

Main file:

package mrmewniverse.core;

import java.util.Map;

import cpw.mods.fml.relauncher.IFMLLoadingPlugin;
import cpw.mods.fml.relauncher.IFMLLoadingPlugin.TransformerExclusions;

@TransformerExclusions({
        "mrmewniverse.core", "mrmewniverse.core.transformer"
})
public class Core implements IFMLLoadingPlugin {

    @Override
    /*
     * Use if you want to download libraries. Returns a list of classes that
     * implement the ILibrarySet interface eg return new String[] {
     * "tutorial.asm.downloaders.DownloadUsefulLibrary " };
     */
    public String[] getLibraryRequestClass() {
        return null;
    }

    @Override
    /*
     * The class(es) that do(es) the transforming. Needs to implement
     * IClassTransformer in some way
     */
    public String[] getASMTransformerClass() {
        return new String[] {
                "mrmewniverse.core.transformer.CoreTransformer"
        };
    }

    @Override
    /*
     * The class that acts similarly to the @Mod annotation.
     */
    public String getModContainerClass() {
        return "mrmewniverse.core.CoreModContainer";
    }

    @Override
    /*
     * If you want to do stuff BEFORE minecraft starts, but after your mod is
     * loaded.
     */
    public String getSetupClass() {
        return null;
    }

    @Override
    /*
     * Gives the mod coremod data if it wants it.
     */
    public void injectData(Map<String, Object> data) {

    }
}

 

Mod Container:

package mrmewniverse.core;

import java.util.Arrays;

import net.minecraftforge.event.EventBus;
import net.minecraftforge.event.ForgeSubscribe;
import cpw.mods.fml.common.DummyModContainer;
import cpw.mods.fml.common.LoadController;
import cpw.mods.fml.common.ModMetadata;
import cpw.mods.fml.common.event.FMLServerStartingEvent;

public class CoreModContainer extends DummyModContainer {

    public CoreModContainer() {
        super(new ModMetadata());

        // The equivalent to mod metadata
        ModMetadata metadata = super.getMetadata();
        metadata.authorList = Arrays.asList(new String[] {
            "MrMewniverse"
        });
        metadata.description = "A test Core mod that will be further developed.";
        metadata.modId = CoreReference.MOD_ID;
        metadata.version = CoreReference.VERSION;
        metadata.name = CoreReference.NAME;
    }

    public boolean registerBus(EventBus par1EventBus, LoadController par2LoadController) {
        par1EventBus.register(this);
        return true;
    }

    @ForgeSubscribe
    public void onServerStarting(FMLServerStartingEvent event) {
        event.getServer().worldServerForDimension(0).spawnHostileMobs = false;
    }
}

 

Class transformer:

package mrmewniverse.core.transformer;

import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import cpw.mods.fml.common.asm.transformers.AccessTransformer;

public class CoreTransformer extends AccessTransformer {

    private static CoreTransformer instance;
    @SuppressWarnings({
            "rawtypes", "unchecked"
    })
    private static List<String> mapFiles = new LinkedList();

    public CoreTransformer() throws IOException {
        super();
        instance = this;

        // Add the transformers here
        mapFiles.add("mrmewniverse_at.cfg");

        Iterator<String> iterator = mapFiles.iterator();
        while (iterator.hasNext()) {
            String file = iterator.next();
            this.readMapFiles(file);
        }
    }

    public CoreTransformer(String par1Str) throws IOException {

    }

    public static void addTransformermap(String par1Str) {
        if (instance == null)
            mapFiles.add(par1Str);
        else
            instance.readMapFiles(par1Str);
    }

    private void readMapFiles(String par1Str) {
        System.out.println("Adding transformer mapping: " + par1Str);
        try {
            Method method = AccessTransformer.class.getDeclaredMethod("readMapFile", new Class[] {
                String.class
            });
            method.setAccessible(true);
            method.invoke(this, new Object[] {
                par1Str
            });
        } catch (Exception exception) {
            throw new RuntimeException(exception);
        }
    }
}

 

the _at.cfg

# MrMewniverse Access Transformer

# World Transformer
public up.G # spawnHostileMobs

# EntityPlayer Transformer
public og.m()V # increaseLevel

# Crafting Manage Transformer
public-f td.a # instance

 

And lastly the metainf stuff

Manifest-Version: 1.0
FMLCorePlugin: mrmewniverse.core.Core

 

And the reference file if needed:

package mrmewniverse.core;

public class CoreReference {

    public static final String MOD_ID = "mrmewniversecore";
    public static final String VERSION = "1.0.0";
    public static final String NAME = "MrMewniverse Core";
}

[/hidden]

[voidzm]

Coremods won't load by default in the Eclipse environment. You have to specify them as an argument in the run configuration.

 

Go to Run > Run Configurations..., select your main configuration (probably Client if you use the default setup), and select the Arguments tab. Insert "-Dfml.coreMods.load=com.example.mod.CoremodPlugin" into the VM Arguments box, just remove the quotes and insert the package/name of your IFMLLoadingPlugin class.

[chrixian]

Coremods won't load by default in the Eclipse environment. You have to specify them as an argument in the run configuration.

 

Go to Run > Run Configurations..., select your main configuration (probably Client if you use the default setup), and select the Arguments tab. Insert "-Dfml.coreMods.load=com.example.mod.CoremodPlugin" into the VM Arguments box, just remove the quotes and insert the package/name of your IFMLLoadingPlugin class.

 

omg  voidzm you've opened up new doors for me  :o :o

 

ty ty ty ty

[chrixian]

Seems so strange that there is no way to transform classes on the fly within the development environment..

ClassTransformers work just fine within eclipse. You just need to keep in mind that your mod code can't rely on the changes then, because eclipse doesn't know about them.

 

Ya I just meant it seems like such a common thing that people would want to do that it wouldn't have been suprising to me to find FML had something as simple as FMLMethodOverrideOMatic("class.oldmethod", "class.newmethod") and CPW/Lex/whoever do whatever sorcery they do and just make it happen automatically lol

[Mew]

And now I am getting the WIERDEST error I have ever seen...

 

package mrmewniverse.core;

 

import java.util.Arrays;

 

import net.minecraftforge.event.ForgeSubscribe;

import cpw.mods.fml.common.DummyModContainer;

import cpw.mods.fml.common.LoadController;

import cpw.mods.fml.common.ModMetadata;

import cpw.mods.fml.common.event.FMLServerStartingEvent;

 

public class CoreModContainer extends DummyModContainer {

 

 

The bold p in the package declaration is underlined red with an error. This is the error:

"The type com.google.common.eventbus.EventBus cannot be resolved. It is indirectly referenced from required .class files"

 

Anyone know how to fix this? Minecraft launches as if there are no errors, but then it DOES crash when it gets to loading my core mod it gets this error:

2013-07-11 07:54:39 [iNFO] [sTDERR] Exception in thread "Minecraft main thread" java.lang.Error: Unresolved compilation problem:

2013-07-11 07:54:39 [iNFO] [sTDERR] The type com.google.common.eventbus.EventBus cannot be resolved. It is indirectly referenced from required .class files

2013-07-11 07:54:39 [iNFO] [sTDERR]

2013-07-11 07:54:39 [iNFO] [sTDERR] at mrmewniverse.core.CoreModContainer.<init>(CoreModContainer.java:1)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.reflect.Constructor.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.Class.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.common.Loader.identifyMods(Loader.java:331)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.common.Loader.loadMods(Loader.java:480)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:163)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.startGame(Minecraft.java:411)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.MinecraftAppletImpl.startGame(MinecraftAppletImpl.java:44)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.run(Minecraft.java:733)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.Thread.run(Unknown Source)

 

 

[EDIT] Also note that this error doesn't appear until I extend DummyModContainer. If I remove it (thus stopping being a core mod) the error disappears...

[culegooner]

Use this tutorial: http://www.minecraftforge.net/wiki/Using_Access_Transformers

 

That covers the basics. If you know what you are doing then you can go from there

 

This tutorial is outdated and keeps misleading a lot of people.

 

The goal of AccessTransformers is just to change a vanilla access level:

 

i.e

private int var;

 

into

 

public int var;

 

and I also see a lot of people doing the same cfg stuff and call without understanding what it does.

 

public up.G # spawnHostileMobs

 

and

 

event.getServer().worldServerForDimension(0).spawnHostileMobs = false;

 

 

as for running in eclipse, you don't have to use the argument, you can create a dummy jar and in the manifest file point to the loading plugin. then copy that jar into mcp/jars/mods

 

I wrote a tutorial on coremods here http://www.minecraftforum.net/topic/1854988-

 

[Mew]

Use this tutorial: http://www.minecraftforge.net/wiki/Using_Access_Transformers

 

That covers the basics. If you know what you are doing then you can go from there

 

This tutorial is outdated and keeps misleading a lot of people.

 

The goal of AccessTransformers is just to change a vanilla access level:

 

i.e

private int var;

 

into

 

public int var;

 

and I also see a lot of people doing the same cfg stuff and call without understanding what it does.

 

public up.G # spawnHostileMobs

 

and

 

event.getServer().worldServerForDimension(0).spawnHostileMobs = false;

 

 

as for running in eclipse, you don't have to use the argument, you can create a dummy jar and in the manifest file point to the loading plugin. then copy that jar into mcp/jars/mods

 

I wrote a tutorial on coremods here http://www.minecraftforum.net/topic/1854988-

 

Yeah I realize that now oops... Anyway. Do you know anything about the error I am getting? It is really starting to bug me...

 

Any help is appreciated

[chrixian]

And now I am getting the WIERDEST error I have ever seen...

 

package mrmewniverse.core;

 

import java.util.Arrays;

 

import net.minecraftforge.event.ForgeSubscribe;

import cpw.mods.fml.common.DummyModContainer;

import cpw.mods.fml.common.LoadController;

import cpw.mods.fml.common.ModMetadata;

import cpw.mods.fml.common.event.FMLServerStartingEvent;

 

public class CoreModContainer extends DummyModContainer {

 

 

The bold p in the package declaration is underlined red with an error. This is the error:

"The type com.google.common.eventbus.EventBus cannot be resolved. It is indirectly referenced from required .class files"

 

Anyone know how to fix this? Minecraft launches as if there are no errors, but then it DOES crash when it gets to loading my core mod it gets this error:

2013-07-11 07:54:39 [iNFO] [sTDERR] Exception in thread "Minecraft main thread" java.lang.Error: Unresolved compilation problem:

2013-07-11 07:54:39 [iNFO] [sTDERR] The type com.google.common.eventbus.EventBus cannot be resolved. It is indirectly referenced from required .class files

2013-07-11 07:54:39 [iNFO] [sTDERR]

2013-07-11 07:54:39 [iNFO] [sTDERR] at mrmewniverse.core.CoreModContainer.<init>(CoreModContainer.java:1)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.reflect.Constructor.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.Class.newInstance(Unknown Source)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.common.Loader.identifyMods(Loader.java:331)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.common.Loader.loadMods(Loader.java:480)

2013-07-11 07:54:39 [iNFO] [sTDERR] at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:163)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.startGame(Minecraft.java:411)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.MinecraftAppletImpl.startGame(MinecraftAppletImpl.java:44)

2013-07-11 07:54:39 [iNFO] [sTDERR] at net.minecraft.client.Minecraft.run(Minecraft.java:733)

2013-07-11 07:54:39 [iNFO] [sTDERR] at java.lang.Thread.run(Unknown Source)

 

 

[EDIT] Also note that this error doesn't appear until I extend DummyModContainer. If I remove it (thus stopping being a core mod) the error disappears...

 

Well it's complaining about not being able to resolve a class from google guava, make sure guava's jar is added as a library on your projects build path