Streamson

A minimalistic dependency-free JSON streaming server (<100loc) and client (1KB).

Installation

To get the server bit:

> npm install streamson

The client:

https://unpkg.com/streamson@latest/dist/streamson.min.js (~1KB)

Usage

Server

import { serve } from "streamson";
import express from "express";

const app = express();
const port = 5009;

app.get("/data", async (req, res) => {
  const myData = {
    title: "My Blog",
    description: "A simple blog example using Streamson",
    posts: getBlogPosts(), // this returns a Promise
  }
  serve(res, myData);
});

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});

getBlogPosts is a function that returns a Promise resolving to an array of blog posts. Of course inside you may have more nested Promises. Like for example each blog post may have comments that are fetched asynchronously:

function getBlogPosts() {
  return Promise.resolve([
    {
      title: "First Post",
      content: "This is my first post",
      comments: fetchCommentsForPost(1), // returns a Promise
    },
    {
      title: "Second Post",
      content: "This is my second post",
      comments: fetchCommentsForPost(2), // returns a Promise
    },
  ]);
}

Streamson will gradually stream the JSON to the client as the Promises get resolved.

Client

const request = Streamson("/data");

const data = await request.get();
console.log(data.title); // "My Blog"

const posts = await request.get('posts');
console.log(posts); // Array of blog posts

Streamson is a global variable available when you include the client script. Notice that the get method can take an optional path argument so you can await on a specific part of the JSON structure. For example request.get() does not wait for the posts to be loaded, but request.get('posts') does. If you don't wait for a specific part, on its place you will get a promise.