EventDispatcher

Process events, post events to server in batch, enrich events by appendig additonal data using simple configuration. Persists events in case of browser reload, closing the browser window (local storage used).

Usage

EventDispatcher is an abstract class. So you need to impliment a class that extends EventDispatcher. Create a service EventDispatcherService that extends EventDispatcher.

// EventDispatcherService.js
import EventDispatcher from "uieventdispatcher";

export class EventDispatcherService extends EventDispatcher {
  constructor() {
    super({
      eventsToPostInSingleCall: 1
    });
  }

  eventEnricher(event) {
    // Modify event if needed
    event.userId = '1KL';
    return event;
  }

  methodToPostEvents(data) {
    return fetch("http://backend-url.com/api/analytics", {
      body: JSON.stringify(data),
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json"
      },
      method: "POST"
    });
  }
}

// Expose the same instance to your whole application 
const eventDispatcher = new EventDispatcherService();
export default eventDispatcher;

In your application code

import eventDispatcher from 'EventDispatcherService';

eventDispatcher.sendEvent({ page: 1});

eventDispatcher.getEventList(); 
/** output
  
  [ { page: 1,
     eventDispatcherUuid: '1548943992704__DEL__126690',   // a unique id generated for eventDispatcher instance
     timeStamp: 1548943992705,                            // timestamp when sendEvent method was called
     userId: '1KL'                                        // modification we did in eventEnricher
    } 
 ]
 x
**/

eventDispatcher.sendEvent({ page: 2}); 
// This will trigger methodToPostEvents as we defined eventsToPostInSingleCall as 1 
// and this is 2nd event we are submitting

Config

EventDispatcher supports following config keys:

| Name | Type | Description | | ------------------------ | --------------------- | -------- | --- | | eventsToPostInSingleCall | number | Wait for these many events before triggering methodToPostEvents|

Abstract methods

The application need to extend EventDispatcher class and impliment these functions.

| Name | Type | Description | | ------------------------ | --------------------- | -------- | --- | | eventEnricher | (event: IEvent) => any | Triggered every time sendEvent is called, can be used to append additonal data to each event.| | methodToPostEvents | (data: any) => Promise | Triggered when after sendEvent method has been called eventsToPostInSingleCall times atleast.| | getLocalStorageKeyName | () => string | Provide a unique string which will be used to store event in localStorage. Should not change on page reload. Bad example: timeStamp, good example: appName_userId |

Supported methods

| Name | arguments in order | Description | | ------------ | ----------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | sendEvent | eventToSend: IEvent; forceful = false; consoleEvent = false | eventToSend: event data; forceful: ignore the check for eventsToPostInSingleCall and call methodToPostEvents or apiPathToPostEvents immidiately; consoleEvent: console.log the event being sent to eventToSend method. Called after eventEnricher if provided | | getEventList | no arguments | Returns the events currently present with eventDispatcher instance | | clearEvents | no arguments | Clear the events currently present with eventDispatcher instance | | getUUID | no arguments | Each EventDispatcher instance gets a unique UUID, use this method to get the |