`filter`

Filters signals based on a predicate function. Only signals that pass the predicate are emitted.

Signature

function filter<T extends Signal>(
  predicate: (signal: T) => boolean
): Operator<T, T>

Example

import { singlePointer } from "cereb";
import { filter } from "cereb/operators";

singlePointer(element)
  .pipe(filter((signal) => signal.value.phase === "move"))
  .on((signal) => {
    // Only move events
  });

Use Cases

Filter by Phase

pan(element)
  .pipe(filter((s) => s.value.phase !== "cancel"))
  .on(handlePan);

Filter by Position

singlePointer(element)
  .pipe(filter((s) => s.value.x > 100))
  .on(handleRightSide);