AJAX-Over-WebSockets

REST / AJAX / RPC – different names, same idea

REST / AJAX / RPC over WebSockets

This repository contains example code for the AJAX over WebSockets tutorial. Despite the different terminology, this example demonstrates the same fundamental interaction model as REST and RPC APIs: a browser calling server-side logic asynchronously without reloading the page.

At a conceptual level, REST, AJAX, and RPC (Remote Procedure Calls) all describe ways for a browser to communicate with a server in the background:

• AJAX describes how the browser sends requests (asynchronously, without page reloads)
• REST and RPC describe how the API is modeled
• The runtime behavior is the same: request → server processing → response

This example uses an RPC-style programming model implemented over WebSockets, but it fulfills the same role as traditional HTTP-based REST or AJAX APIs. The main difference is that WebSockets provide a persistent, bidirectional connection, eliminating repeated HTTP request overhead.

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Why WebSockets?

WebSockets establish a long-lived connection between the browser and server, making them ideal for:

• Low-latency, interactive applications
• Real-time updates
• Efficient request/response exchanges without repeated connection setup

In this example, WebSockets are used as a transport layer. On top of that transport, the API behaves like a familiar AJAX or RPC interface.

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Getting started

To run the example, start the Mako Server in the project directory:

cd AJAX-Over-WebSockets
mako -l::www

For more details on starting the Mako Server, see:

• The command-line video tutorial: https://youtu.be/vwQ52ZC5RRg
• Mako Server command-line options: https://realtimelogic.com/ba/doc/en/Mako.html#cmdline

Once the server is running, open a browser and navigate to:

http://localhost:<port_number>

The port number is displayed in the Mako Server console output.

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Example files

The following files demonstrate AJAX / RPC-style communication over WebSockets:

• www/index.html
  The original example, based on jQuery, demonstrating the AJAX WebSocket client library.

• www/promise.html
  A modernized version using the native DOM APIs, Promises, and async / await for clearer asynchronous code.

• www/service.lsp
  The server-side Lua Server Pages (LSP) script implementing the WebSocket-based service logic.

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How this relates to REST

Although the API is not expressed as REST-style URLs, the interaction pattern is equivalent:

• The browser sends a request for server-side processing
• The server executes logic and returns structured data
• The browser updates the UI without a page reload

Many real-world REST APIs are effectively RPC expressed through HTTP verbs and URLs. This example shows the same pattern implemented more directly using WebSockets as the transport.

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Learn more

For a detailed walkthrough of the concepts and code, see the full tutorial:

https://makoserver.net/articles/AJAX-over-WebSockets

See Also

• REST / AJAX / RPC over SMQ