Class System

ReadonlyafterEvents

ReadonlycurrentTick

clearJob

• clearJob(jobId: number): void

• Parameters

  • jobId: number

    The job ID returned from System.runJob.

  Returns void

  Remarks

  Cancels the execution of a job queued via System.runJob.

clearRun

• clearRun(runId: number): void

• Parameters

  • runId: number

  Returns void

  Remarks

  Cancels the execution of a function run that was previously scheduled via System.run.

  Example: clearRun.js

  import { system } from "@minecraft/server";
  
  const runId = system.run(() => {
      console.log("Running callback function...");
  });
  
  // Clear the run, so it will not run again.
  system.clearRun(runId);
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run

• run(callback: () => void): number

• Parameters

  • callback: () => void

    Function callback to run at the next game tick.

  Returns number

  An opaque identifier that can be used with the clearRun function to cancel the execution of this run.

  Remarks

  Runs a specified function at the next available future time. This is frequently used to implement delayed behaviors and game loops. When run within the context of an event handler, this will generally run the code at the end of the same tick where the event occurred. When run in other code (a system.run callout), this will run the function in the next tick. Note, however, that depending on load on the system, running in the same or next tick is not guaranteed.

  Example: trapTick.ts

  import { system, world } from '@minecraft/server';
  
  function printEveryMinute() {
      try {
          // Minecraft runs at 20 ticks per second.
          if (system.currentTick % 1200 === 0) {
              world.sendMessage('Another minute passes...');
          }
      } catch (e) {
          console.warn('Error: ' + e);
      }
  
      system.run(printEveryMinute);
  }
  
  printEveryMinute();
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  Example: run.js

  import { system } from "@minecraft/server";
  
  const runId = system.run(() => {
      console.log("Running callback function...");
  });
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runInterval

• runInterval(callback: () => void, tickInterval?: number): number

• Parameters

  • callback: () => void

    Functional code that will run when this interval occurs.
  • OptionaltickInterval: number

    An interval of every N ticks that the callback will be called upon.

  Returns number

  An opaque handle that can be used with the clearRun method to stop the run of this function on an interval.

  Remarks

  Runs a set of code on an interval.

  Example: every30Seconds.ts

  import { system, world } from '@minecraft/server';
  
  const intervalRunIdentifier = Math.floor(Math.random() * 10000);
  
  system.runInterval(() => {
      world.sendMessage('This is an interval run ' + intervalRunIdentifier + ' sending a message every 30 seconds.');
  }, 600);
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runJob

• runJob(generator: Generator<void, void, void>): number

• Parameters

  • generator: Generator<void, void, void>

    The instance of the generator to run.

  Returns number

  An opaque handle that can be used with System.clearJob to stop the run of this generator.

  Remarks

  Queues a generator to run until completion. The generator will be given a time slice each tick, and will be run until it yields or completes.

  Example: cubeGenerator.ts

  import { BlockPermutation, DimensionLocation, world, ButtonPushAfterEvent, system } from '@minecraft/server';
  
  // A simple generator that places blocks in a cube at a specific location
  // with a specific size, yielding after every block place.
  function* blockPlacingGenerator(blockPerm: BlockPermutation, startingLocation: DimensionLocation, size: number) {
      for (let x = startingLocation.x; x < startingLocation.x + size; x++) {
          for (let y = startingLocation.y; y < startingLocation.y + size; y++) {
              for (let z = startingLocation.z; z < startingLocation.z + size; z++) {
                  const block = startingLocation.dimension.getBlock({ x: x, y: y, z: z });
                  if (block) {
                      block.setPermutation(blockPerm);
                  }
                  yield;
              }
          }
      }
  }
  
  // When a button is pushed, we will place a 15x15x15 cube of cobblestone 10 blocks above it
  world.afterEvents.buttonPush.subscribe((buttonPushEvent: ButtonPushAfterEvent) => {
      const cubePos = buttonPushEvent.block.location;
      cubePos.y += 10;
  
      const blockPerm = BlockPermutation.resolve('minecraft:cobblestone');
  
      system.runJob(blockPlacingGenerator(blockPerm, { dimension: buttonPushEvent.dimension, ...cubePos }, 15));
  });
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runTimeout

• runTimeout(callback: () => void, tickDelay?: number): number

• Parameters

  • callback: () => void

    Functional code that will run when this timeout occurs.
  • OptionaltickDelay: number

    Amount of time, in ticks, before the interval will be called.

  Returns number

  An opaque handle that can be used with the clearRun method to stop the run of this function on an interval.

  Remarks

  Runs a set of code at a future time specified by tickDelay.

  Example: runTimeout.js

  import { TicksPerSecond, system } from "@minecraft/server";
  
  system.runTimeout(() => {
      console.log("Running callback function after delay...");
  }, TicksPerSecond * 5); // Tick delay of 5 seconds
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waitTicks

• waitTicks(ticks: number): Promise<void>

• Parameters

  • ticks: number

  Returns Promise<void>

  Throws

  This function can throw errors.

  minecraftcommon.EngineError