Parallel Workflow Activity

The parallel activity is used to execute multiple activities in parallel. You can select the branches to execute based on the workflow state.

import { BranchedStep } from 'sequential-workflow-model';
import { createParallelActivity, interrupt, branchName, BranchNameResult } from 'sequential-workflow-machine';

interface ParallelStep extends BranchedStep {
  type: 'parallel';
  componentType: 'switch';
  /* ... */
}

const parallelActivity = createParallelActivity<ParallelStep, MyGlobalState, MyActivityState>('parallel', {
  init: () => {
    return {}; // Initial activity state
  },
  handler: async (step: ParallelStep, globalState: MyGlobalState, activityState: MyActivityState) => {
    if (globalState.temperature < 0) {
      return interrupt();
    }
    const branches: BranchNameResult[] = [
      branchName('branch1')
    ];
    if (globalState.temperature > 10 && globalState.temperature < 20) {
      branches.push(branchName('branch2'));
    }
    return branches;
  }
});