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Sharing state between scripts ​

Ordinary script variables belong to one execution context. If two triggers run the same file, each run has its own variables. To share a value between runs, scripts, or profiles, use GlobalVars.

GlobalVars is a named map of Java values shared by scripts in the same JsMacros runtime. The library is created once, so a profile switch does not clear it. Values stay until they are removed or the game session ends.

Typed values ​

Use the typed setters and getters:

js
GlobalVars.putInt("runs", 0);
GlobalVars.putString("lastPlayer", "Steve");
GlobalVars.putDouble("ratio", 0.5);
GlobalVars.putBoolean("enabled", true);

const runs = GlobalVars.getInt("runs");       // Integer or null
const name = GlobalVars.getString("lastPlayer");
const type = GlobalVars.getType("runs");     // "Int"

The typed getters do not coerce. If runs was stored as a double, getInt("runs") returns null, not a truncated integer. Check getType when a key can hold more than one shape.

The getters return Java values. Template literals interpolate them normally when you build a message.

Atomic counters ​

The increment methods are atomic, which matters when two scripts update the same counter at once:

js
const next = GlobalVars.incrementAndGetInt("runs");
Chat.log(`this is run ${next}`);

const previous = GlobalVars.getAndIncrementInt("runs");
Chat.log(`the previous value was ${previous}`);

getAndIncrementInt returns the old value; incrementAndGetInt returns the new one. The decrement variants work the same way.

Complex values ​

putObject accepts a Java object, not a guest JavaScript object:

js
const map = JavaUtils.createHashMap();
map.put("count", 1);
GlobalVars.putObject("state", map);

const state = GlobalVars.getObject("state");

Passing a JavaScript object throws an assertion error. If you need structured data, build a Java collection or map through JavaUtils, or write JSON to a file with FS. A plain JavaScript object is tied to one script context and cannot be shared safely.

getRaw() returns the live backing map. Writes through it bypass the guest-object check, so prefer the typed methods unless you are deliberately working with the whole map.

What not to use it for ​

  • Large caches. GlobalVars is a map, not a database. Use FS for data that should survive a restart.
  • Per-run temporary state. Use local variables. They are easier to reason about and are released with the context.
  • Profile-specific state. GlobalVars is shared, not per profile. If two profiles must not see each other's values, prefix keys by profile or write separate files.

Example: remember when each player was last seen ​

js
const players = World.getPlayers();
if (players === null) {
  // cconsole.log outputs to the Minecraft log file (STDOUT). Chat.log wouldn't be visible given there's no chat visible.
  console.log("join a server first");
} else {
  const now = Time.time();
  for (let i = 0; i < players.size(); i += 1) {
    const name = players.get(i).getName();
    if (name === null) continue;

    const key = `lastSeen.${name}`;
    const stored = GlobalVars.getDouble(key);
    const lastSeen = stored === null
      ? "first seen"
      : `last seen ${new Date(Number(stored)).toLocaleString()}`;
    Chat.log(`${name}: ${lastSeen}`);

    GlobalVars.putDouble(key, now);
  }
}