workflow-it

Run async tasks in a series of steps.

Unlike Promise.all, which runs all tasks in parallel, workflowit will run each task in sequence they were added to the workflow object.

This is useful for when you are tying to put a bunch of tasks back to back without each one stepping over each other.

Okay, tell me more.

With workflowit, you create a Workflow object, and add Steps which represent your task. The function you pass into your step can optionally return a promise.

function showTermsOfService() {
    tosWgt.show();
}
function showReleaseNotes() {
    return service.fetchReleaseNotes().then(function (notes) {
        rnWgt.show(notes);
    });
}
// The task function is passed the step and workflow object.
function showWelcome(step, workflow) {
    welcomeWgt.show(workflow.name, step.name);
}

// Setup the workflow.
var Workflow = require("workflowit");

// Create workflow and add steps.
var wf = new Workflow("startup")
    .addStep(new Workflow.Step("tos", showTermsOfService))
    .addStep(new Workflow.Step("rn", showReleaseNotes))
    .addStep(new Workflow.Step("welcome", showWelcome));

// You can also provide steps directly in the constructor
var wf = new Workflow(
    "startup",
    new Workflow.Step("tos", showTermsOfService),
    new Workflow.Step("rn", showReleaseNotes),
    new Workflow.Step("welcome", showWelcome)
);

// Later....
wf.run().done();

In the above example, rn won't run until tos promise has resolved, similarly, welcome won't run until rn has completed.

You can listen for events.

wf.on("step", function (step, progress) {
    console.log("We are at step " + step.name + " with progress " + progress);
}

// The step event handler would get 3 times from the above setup.
// The step being the `Workflow.Step` object, and the progress being
// `1/3` for the first, `2/3` for the second, and `1` for the last event.

wf.on("exec", function () {
    console.log("we are done!");
});

All events can return a promise.

The Worflow.Step object emits an exec event when it has complted running.

step.on("exec", function (wf) {
    console.log(step.name + " just ran for the wf: " + wf.name);
}

You can of course extend, swap Workflow and Workflow.Step.

interface Workflow {
    addStep(step: WorkflowStep);
    run(): Promise;
}

interface WorkflowStep { // Yup just a command.
    exec();
}