API_TRANSITION_GUIDE.md

Deprecated API Transition Guide

When APIs are deprecated, the following guide will show how to transition from removed APIs to the new ones

Upgrading From 3.x to 4.0

In the 3.2.0 release, a few APIs were set to be deprecated in the 4.0 release. With the release of 4.0.0, those APIs have been removed.

Receiever

The Receiver class has been removed.

Receiver.accept should be transitioned to HTTP.toEvent

Here is an example of what a HTTP.toEvent might look like using Express.js

const app = require("express")();
const { HTTP } = require("cloudevents");

app.post("/", (req, res) => {
  // body and headers come from an incoming HTTP request, e.g. express.js
  const receivedEvent = HTTP.toEvent({ headers: req.headers, body: req.body });
  console.log(receivedEvent);
});

Emitter

Emit.send should be transitioned to HTTP.binary for binary events and HTTP.structured for structured events

Emit.send would use axios to emit the events. Since this now longer available, you are free to choose your own transport protocol.

So for axios, it might look something like this:

const axios = require('axios').default;
const { HTTP } = require("cloudevents");


const ce = new CloudEvent({ type, source, data })
const message = HTTP.binary(ce); // Or HTTP.structured(ce)

axios({
  method: 'post',
  url: '...',
  data: message.body,
  headers: message.headers,
});

You may also use the emitterFor() function as a convenience.

const axios = require('axios').default;
const { emitterFor, Mode } = require("cloudevents");

function sendWithAxios(message) {
  // Do what you need with the message headers
  // and body in this function, then send the
  // event
  axios({
    method: 'post',
    url: '...',
    data: message.body,
    headers: message.headers,
  });
}

const emit = emitterFor(sendWithAxios, { mode: Mode.BINARY });
emit(new CloudEvent({ type, source, data }));

You may also use the Emitter singleton

const axios = require("axios").default;
const { emitterFor, Mode, CloudEvent, Emitter } = require("cloudevents");

function sendWithAxios(message) {
  // Do what you need with the message headers
  // and body in this function, then send the
  // event
  axios({
    method: "post",
    url: "...",
    data: message.body,
    headers: message.headers,
  });
}

const emit = emitterFor(sendWithAxios, { mode: Mode.BINARY });
// Set the emit
Emitter.on("cloudevent", emit);

...
// In any part of the code will send the event
new CloudEvent({ type, source, data }).emit();

// You can also have several listener to send the event to several endpoint