@softwareasaservice/events NPM

events, a minimal user journey automation package for Node/React

Build conversion and user journey automations based on events happening or not happening over a period of time.

Pass timeouts using the ms package which is the only dependency for this package.

The system is simple. You push/ingest events. And you have one workflow function that is called automatically when an event in ingested, allowing you to build event-based automations. There are no cloud based or networking features. But you can over-ride the in-memory version for eg: to set and get from s3/a database, etc.

The innovation is a temporal/inngest style workflow/queing engine where the emphasis is on being developer friendly.

Demo

Here is an example of 1 user generated event app/email.submitted triggering a workflow involving reminders for opening an account, for verifying email, and for creating 2 posts.

creating event users[user1][app/email.submitted]
	waited 1s for account.created for user  { id: 'user1' }
        send reminder to create account
creating event users[user1][reminder/account.created]
	waited 2s for account.created for user  { id: 'user1' }
        send reminder to create account
creating event users[user1][reminder/account.created]
	waited 4s for account.created for user  { id: 'user1' }
        send reminder to create account

// notice exponential backoff for reminders

creating event users[user1][reminder/account.created]
creating event users[user1][app/account.created]
	waited 6s for app/email.verified
        no email verified, wait for it
creating event users[user1][app/email.verified]
creating event users[user1][app/login]
creating event users[user1][app/post.created]
	waited 2s for post2 created
        send reminder to write post2
creating event users[user1][app/post.created]
	waited 2s for post2 created
        send reminder to write post2
creating event users[user1][app/post.created]
	end of workflow

All times in this example have been made in seconds but you can very well replace it with 1d, 7d or minutes/seconds/days/weeks/months as you see fit.

Code for the example workflow of 5 automations

var Events = require('@softwareasaservice/events').Events;

var events = new Events({id:"user1"}, {workflow})	
  
async function workflow({user}){
	// read in-memory store events.users. 
    var data = events.users[user.id];
  
    // waitFor returns an object with {result:undefined|object}
    // result undefined meaning it's still not done

    // check if any reminders were sent
    var reminders = await events.waitFor(user, 'reminder/account.created', {match:{email: data.email}, timeout:'1s'});

    // then do exponential backoff reminders
    var expBackoff1 = (reminders.result? reminders.result.length*2:1)+'s';
    var userData = await events.waitFor(user, 'app/account.created', {match:{email: data.email}, timeout: expBackoff1});
    if(!userData.result){
        console.log('waited '+expBackoff1+' for account.created for user ', user);
        console.log('\tsend reminder to create account');
        return await events.ingest({event:'reminder/account.created', data:{email: data.email}, user:user});
    }

	// at this point user account is created
    user = userData.result[0];
    
    var emailVerified = await events.waitFor(user, 'app/email.verified', {match:{userId:user.id}, timeout:'6s'});

    if(emailVerified.result){
        var post1Created = await events.waitFor(user, 'app/post.created', {match:{id:'post1'}, timeout:'2s'});
        
        if(!post1Created?.result){
            console.log('waited 6s for post1 created');
            console.log('\tsend reminder to write post1');
            return;
        }else{
            var post2Created = await events.waitFor(user, 'app/post.created', {match:{id:'post2'}, timeout:'2s'});
            if(!post2Created?.result){
                console.log('waited 2s for post2 created');
                console.log('\tsend reminder to write post2');
            }else{
                console.log('end of workflow');

// return a result to end the workflow return {result: post2Created} } } }else{ console.log('waited 6s for app/email.verified'); console.log('\tno email verified, wait for it'); } }

Sleep

// waits for 30 seconds
await events.sleep("30s")

// waits for 1 hour
await events.sleep("1h")

// anything passed in second argument is given back in the response
var foo = await events.sleep("1h", {foo:"bar"}).foo

Install

# with yarn 
yarn add @softwareasaservice/events

# or with npm
npm install @softwareasaservice/events

Usage

var Events = require('@softwareasaservice/events').Events;

var events = new Events({"id":"user2"}, {workflow})

Pushing events

var Events = require('@softwareasaservice/events').Events;

var events = new Events({"id":"user3"}, {workflow:(){}})	
// uses in-memory store 

var user = {id: "user1"};
var event = "someEvent";
var data = {"foo":"bar", "level":2};

// push events to in-memory store
events.ingest({event, data})

Replace in-memory store

var Events = require('@softwareasaservice/events').Events;

// To use your own stores, pass in your setter, getter functions
var events = new Events({workflow, checkEvent, setEvent})

// To use an S3 store
// const {setup, checkEvent, setEvent} = require('@softwareasaservice/eventsworkflows3');
var events = new Events({workflow, checkEvent, setEvent}, {
    S3:{
        OBJECT_STORE_PREFIX:'some-prefix-in-your-bucket/', 
        client: myS3Client // should implement get(_path),list(_path), put(_path, jsonObj)
    }
})

checkEvent and setEvent takes {user, data, event}. See the source code for learning how to create your own setters and getters that possibly read/write to a persistent storage like s3/minio or a database.