Problem sending message to player

[TehNoiseBomb]

I've run into a problem while developing my mod where I want to send a chat message to the player when a block receives a redstone pulse. When testing the mod, I get an error:

java.lang.NullPointerException: Exception while updating neighbours

. My code:

 

 

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@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          if(w.isBlockIndirectlyGettingPowered(x, y, z)){
               w.getClosestPlayer((double)x, (double)y, (double)z, 0)
                    .addChatMessage(
                         new ChatComponentText("test message"));}
     }
}

 

 

The error occurs on the .addChatMessage() line.

[shieldbug1]

You're trying to get the nearest player to the block in a radius of 0. You need to make sure that player is not null before trying to do anything because World#getClosestPlayer(double,double,double,int) can return null.

[TehNoiseBomb]

OK, so I added in the check to see if the player is null or not and changed the getClosestPlayer to 5 and it works now.

 

 

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@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          [bold]EntityPlayer player = w.getClosestPlayer((double)x, (double)y, (double)z, 5);
          if(player!=null){[/bold]
               if(w.isBlockIndirectlyGettingPowered(x, y, z)){
                    player.addChatMessage(
                         new ChatComponentText("test message"));
            }
               }
          }
}

 

 

However for some reason the chat message is firing twice. Any ideas?

[coolboy4531]

I'm pretty sure it is being fired twice on the server.

[TehNoiseBomb]

Yea that's what I'm thinking. I tried adding in @SideOnly(Side.CLIENT) before the function but that didn't change anything.

[Draco18s]

  On 12/23/2014 at 9:32 PM, TehNoiseBomb said:

Yea that's what I'm thinking. I tried adding in @SideOnly(Side.CLIENT) before the function but that didn't change anything.

 

That's not what @SideOnly is for.

[TehNoiseBomb]

I figured that out but the problem persists. Is there any way to have the message be sent to the player without it being duplicated?

[shieldbug1]

Wrap the code in

if(!world.isRemote)

[TehNoiseBomb]

  On 12/24/2014 at 12:53 AM, shieldbug1 said:

Wrap the code in

if(!world.isRemote)

 

I have that. As a refresher:

 

 

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@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          EntityPlayer player = w.getClosestPlayer((double)x, (double)y, (double)z, 5);
          if(player!=null){
               if(w.isBlockIndirectlyGettingPowered(x, y, z)){
                    player.addChatComponentMessage(new ChatComponentText("test message"));
               }
          }
     }
}

 

[TehNoiseBomb]

I have decided to go a different path with what I was trying to achieve with this. Instead of giving the player the information through a chat message, I am having the player place a sign above my mod block that automatically loads the sign with the information I want to display.

 

If you are interested in how I achieved this my code is below (sorry, I'm not formatting it this time ):

 

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@Override
    public void onNeighborChange(IBlockAccess w, int x, int y, int z, int tileX, int tileY, int tileZ){
	if(w.getBlock(x, tileY, z)==Blocks.standing_sign||w.getBlock(x, tileY, z)==Blocks.wall_sign){
		this.sign = (TileEntitySign)w.getTileEntity(x, y+1, z);
		signText();
	}
    }
//This is in it's own method because I call it from elsewhere to have the sign be updated when the information changes.
private void signText(){ 
	this.sign.signText[0]="line0";
	this.sign.signText[1]="line1";
	this.sign.signText[2]="line3";
}

@Override
public boolean canPlaceBlockAt(World w, int x, int y, int z)
    {
	if(w.getBlock(x, y+1, z).isAir(w, x, y+1, z)){
		return w.getBlock(x, y, z).isReplaceable(w, z, y, z);
	}
	else return false;
    }
[/spoiler]