Minecraft – Need Help With a command: testforblock near Player!

minecraft-commandsminecraft-java-edition

Hi I am trying to make my own Custom Crafting Dropper, I Need to testforblock near the player to find a dropper with the ingredients.

I tried this:

execute @p[r=10] ~ ~ ~ /testforblock ~ ~ ~ dropper 1 {Items:[0:{Slot:0b,id:"minecraft:stone",Count:1b,Damage:0s,},1:{Slot:1b,id:"minecraft:stone",Count:1b,Damage:0s,},2:{Slot:2b,id:"minecraft:stone",Count:1b,Damage:0s,},3:{Slot:3b,id:"minecraft:stone",Count:1b,Damage:0s,},4:{Slot:4b,id:"minecraft:redstone_block",Count:1b,Damage:0s,},5:{Slot:5b,id:"minecraft:stone",Count:1b,Damage:0s,},6:{Slot:6b,id:"minecraft:stone",Count:1b,Damage:0s,},7:{Slot:7b,id:"minecraft:stone",Count:1b,Damage:0s,},8:{Slot:8b,id:"minecraft:stone",Count:1b,Damage:0s,},],id:"Dropper",Lock:"",}

But the command can't find the dropper.

My plan is that I will spawn a dropper from A villager named "Test" using

execute @e[name=Test] ~ ~ ~ /setblock ~ ~ ~ dropper

and then the villager will die

kill @e[name=Test]

The testforblock will test if the ingredients are inside the dropper and I will clone the dropper with the results from the custom crafting and replace the dropper with The ingredients.

Best Answer

The problem is that your command is looking for a player within a radius of 10 of the command block, standing inside a dropper with specific items in it. That won't do.

In fact, it is quite difficult to detect the presence of a single, arbitrary block in the vicinity of the player. Luckily for you, your dropper is not arbitrary, but is created at the position of an entity (your villager)!

What you want to do is keep this villager alive. Let me back up a little. You want to use an armor stand instead, they are the gold standard for use as entity markers for commands, due to the Marker, NoGravity and Invisible tags.

Now that you are using an armorstand, don't kill it, and use the following command to detect the dropper:

execute @e[type=ArmorStand,name=Test] ~ ~ ~ testforblock ...

The armorstand serves to save arbitrary coordinates and execute from there, similar to how you create the dropper at an arbitrary place.

It doesn't really matter if the player is within 10 blocks, but if you really want to, you can daisy-chain execute commands

execute @a ~ ~ ~ execute @e[type=ArmorStand,name=Test,r=10] ~ ~ ~ testforblock ...

This will run the second execute (and everything beyond) only if the armorstand is within 10 blocks of any player.

Related Solutions

Minecraft – Detect a dropper with items in it without /testfor

The detect function of /execute does not accept NBT data, only an ID and Damage value.

You will instead need to use /testforblock, and if needing multiplayer-friendliness, mixing it with CommandStats.

Prerequisites:

Objective to hold the CommandStats value.

/scoreboard objectives add CraftSuccess dummy

Applying the AffectedBlocks trigger to players, which will set the player's score based on the success of commands that specifically affect blocks, such as /testforblock. This may need to run on a clock in the event new players can join at any time.

/stats entity @a set AffectedBlocks @a[c=1] CraftSuccess

In order for CommandStats to modify a target's score, that target must be tracked on the scoreboard prior. This may also need to run on a clock for the same reason as before.

/scoreboard players add @a CraftSuccess 0

Detection:

The following must be run in numerical order.

Cause players to run the necessary /testforblock command.

/execute @a ~ ~ ~ /testforblock ~ ~-1 ~ minecraft:dropper 1 {Items:[{id:"minecraft:blaze_rod",Slot:1b,Count:1b,Damage:0s},{id:"minecraft:blaze_rod",Slot:4b,Count:1b},{id:"minecraft:stick",Slot:7b,Count:1b}]}

As a result, the executing player will have their own "CraftSuccess" score set equal to the number of blocks found by the /testforblock command. If the command failed, their score is set to 0. If the command succeeded, their score is set to 1. You'd then target players based on their score.
```
/scoreboard players set @a[score_CraftSuccess_min=1] LSC 1
```

As a side-note, you should never mix @a as an executor and @p as the nested command's target if you're intended to target the same player. While @a can target dead players, @p cannot. That means that while the executor can run /execute while they're dead, they will not target themselves and instead target the nearest-living player. This can severely hurt accuracy and possibly break a target-sensitive mechanism.

The solution is to use the same selector when needed. For dead player targeting, you'd use @a as the executor with @a[c=1] as the nested selector:

/execute @a ~ ~ ~ /say @a[c=1]

For living-only players, you'd use @e[type=Player] with @p:

/execute @e[type=Player] ~ ~ ~ /say @p

It is also for this reason that CommandStat targets should use @a[c=1] when working with players, as this ensures there will not be an unintended target having their score modified.

Minecraft – How to mark a entity after it executes a command successfully

You will want to use CommandStats, which are a set of triggers stored on an entity that will modify a target's score based on the success of commands run by the entity.

For example, you will want to use the "SuccessCount" trigger, which stores the number of successful iterations of a command (and in the case of /testforblocks, will either be 0 for failure or 1 for success). You could also use "AffectedBlocks", which returns the number of matched blocks (0 for failure or the number of blocks found via /testforblocks).

Prerequisites

Objective to hold the return value from CommandStats triggers:

/scoreboard objectives add Results dummy

You have a couple options for applying the triggers to the entities. The most direct way would be to use the CommandStats compound directly when summoning:

/summon ArmorStand ~ ~1 ~ {CustomName:"craft",CommandStats:{SuccessCountName:"@e[type=ArmorStand,c=1]",SuccessCountObjective:"Results"}}

Or you could use the /stats command. The second selector is not translated in this command, and is stored as literally written in the CommandStats compound like above:

/stats entity @e[type=ArmorStand,name=craft] set SuccessCount @e[type=ArmorStand,c=1] Results

In order for these triggers to modify a target's score, that target must be tracked in the objective prior.

/scoreboard players set @e[type=ArmorStand,name=craft] Results 0

Detection

Your initial command.

/execute @e[type=ArmorStand,name=craft] ~ ~ ~ /testforblocks -15 56 -225 -15 56 -225 ~ ~ ~

Now the armor stand will have a "Results" score of 1 if it succeeded or 0 if it failed. You can then target the relevant armor stands.

/execute @e[type=ArmorStand,name=craft,score_Results_min=1] ~ ~ ~ /blockdata ~ ~ ~ {Items:[0:{Slot:4b,id:"minecraft:spawn_egg",Count:1b,tag:{RepairCost:0,display:{Name:"Sponge"},EntityTag:{id:"Blaze"}},Damage:0s}]}

There is no need to reset their score to 0 because it will do so the next time /testforblocks fails.