Modernize Legacy Systems with Webfuse:
Step-by-Step Guide

Many organizations depend on legacy web applications for important business functions. These systems, while reliable, often come with outdated user interfaces, limited features, and are difficult to update. The conventional path involves a costly and time-consuming migration to a new platform, which introduces major risks and disruptions.

There is another way to approach this problem. Using a method called web augmentation, we can layer modern features and an improved user experience directly on top of existing applications. This is done without altering the original source code.

In this guide I'll walk you through a practical example of this process using Webfuse. We will take a fictional inventory system and give it a modern update, making it more intuitive and useful for its users.

The Legacy System Challenge

Let's look at our target for modernization: InventTrack Pro. This is a simple, browser-based inventory management tool. While it holds important data, its presentation and functionality are limited.

The main problems with InventTrack Pro are:

• Poor Data Visualization: The inventory is just a plain HTML table of text and numbers.
• Lack of Modern Features: There is no easy way for a user to ask for help or report an issue directly from the page.

Our goal is to fix these issues without touching the InventTrack Pro server or asking users to install anything.

Web Augmentation: Modernization Without Migration

Web augmentation allows us to inject new code—HTML, CSS, and JavaScript—into a web page as it loads for the user. Webfuse manages this process through a augment proxy engine (AWP). A user clicks a Webfuse link, and the platform fetches the original legacy application, applies our modifications in the cloud, and then delivers the enhanced version to the user's browser.

This results in benefits such as:

• Speed: We can deploy changes in minutes, not months.
• Low Risk: The original application remains untouched.
• Zero End-User Setup: Users just click a link. There are no browser extensions to install or manage.

Modernizing InventTrack Pro

We will perform two main upgrades to InventTrack Pro. First, we'll add visual indicators to the inventory table to show stock levels. Second, we'll add a modern chat widget for on-demand support.

This makes the interface more intuitive and adds a valuable communication channel.

Step-by-Step Implementation Guide

Now, let's walk through the exact steps to make this happen.

Prerequisites

Before you start, you will need a Webfuse account and the URL for the legacy web application you want to modernize. For this example, we'll use a demo URL: https://testsite.surfly.com/legacy.html.

Step 1: Create a Webfuse Space

A "space" in Webfuse is a container for your augmentation project. It defines the target website and holds all your configurations and extensions.

Start by logging into Webfuse Studio and creating a new space for your modernization project.

1. Choose a space type. For this project, "Solo" is a suitable choice as it's designed for individual experiences, though it can be shared.
2. Enter a descriptive name for your project, such as "inventory-system-upgrade" and click the "Next" button to continue.

Step 2: Configure Space Settings

Next, we can set some basic access controls. For this guide, we'll keep it simple.

Leave access controls and permissions to their defaults and click the "Open" space button to proceed.

• Access control: You can choose "Public" for easy sharing or "Members only" to restrict access to specific team members.
• Team members: Here you can invite others who might need to help manage the project or use the modernized system.

Step 3: Configure Your Start Page

The start page tells Webfuse which URL to load when a user opens your space. We need to point it to our legacy InventTrack Pro application.

In your space settings, navigate to the "Start Page" section. You will select the option to open a specific page and then add the URL of the legacy system.

In the modal that appears, enter the URL of the legacy application, which is https://testsite.surfly.com/legacy.html for our example. Click "Add Page" to confirm.

Finally, save your changes.

Now, whenever someone visits your Webfuse space URL, they will be taken directly to a session running the legacy inventory application, ready for augmentation.

Step 4: Prepare the First Modernization (Visual Indicators)

A Webfuse Session Extension is a package of code that runs inside your space to modify the target application. We'll start by creating an extension that adds visual stock indicators to the inventory table.

Our extension needs two files. First, create a file named manifest.json. This file provides metadata about our extension.

{
  "manifest_version": 3,
  "name": "Simple Inventory Modernizer",
  "version": "1.0",
  "description": "A simple extension to modernize legacy inventory systems with visual indicators and mini charts",

  "content_scripts": [
    {
      "matches": ["*://*/*"],
      "js": ["content.js"]
    }
  ],

  "permissions": [
    "activeTab"
  ]
}

Next, create the JavaScript file named content.js. This file contains the logic for our first visual upgrade.

// Add visual stock indicators
function addSimpleCharts() {
    // Find all the data rows in our inventory table
    const rows = document.querySelectorAll('#inventory-data tr');

    // Go through each row one by one
    rows.forEach(row => {
        // The quantity is in the 5th cell (index 4)
        const qtyCell = row.cells[4];

        // Make sure the cell exists and contains a number
        if (qtyCell && !isNaN(parseInt(qtyCell.textContent))) {
            const qty = parseInt(qtyCell.textContent);

            // Create a new visual element (a div) to act as our bar
            const bar = document.createElement('div');

            // Style the bar. If quantity is over 50, make it green. Otherwise, red.
            bar.style.cssText = `
                display: inline-block;
                width: 40px;
                height: 8px;
                background: ${qty > 50 ? 'green' : 'red'};
                margin-left: 5px;
            `;

            // Add the new bar inside the quantity cell
            qtyCell.appendChild(bar);
        }
    });
}

// Function to run our code once the page is ready
function init() {
    addSimpleCharts();
}

// Make sure the page is loaded before we try to modify it
if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
} else {
    init();
}

Save these two files inside a new folder named inventory-modernization. This folder is the extension package we'll upload.

Step 5: Upload and Test the First Extension

With the extension ready, let's apply our first change.

From within your space, click on the "Extensions" tab in the top right bar. Select "Default storage," and then click the "Upload from computer" button.

You will be prompted to select the extension to upload. Choose the inventory-modernization folder you just created.

Once uploaded, close the notification sidebar.

Terminate your Webfuse space session.

And restart the session for the new extension code to be executed.

You should now see the legacy application, but with a small red or green bar next to each quantity, giving an immediate visual cue about stock levels.

Step 6: Enhance the Extension (Adding a Chat Widget)

With our first success validated, let's add the chat widget. We don't need a new extension; we can simply update our existing content.js file.

Open content.js and add the following new function:

// Add modern chat widget
function addChatWidget() {
    // Create the main element for our chat button
    const chat = document.createElement('div');
    chat.innerHTML = '💬 Chat';

    // Style the button to float in the bottom-right corner
    chat.style.cssText = `
        position: fixed;
        bottom: 20px;
        right: 20px;
        background: blue;
        color: white;
        padding: 10px;
        border-radius: 5px;
        cursor: pointer;
    `;

    // Add a simple action when the button is clicked
    chat.addEventListener('click', () => {
        alert('Chat feature activated! You can now get help with your inventory.');
    });

    // Add the chat button to the page
    document.body.appendChild(chat);
}

Now, modify the init function to call both of our new functions. Your final content.js file should look like this:

console.log("Simple Inventory Modernizer Loading...");

// Main entry point - auto-start modernization
function init() {
    addSimpleCharts();
    addChatWidget();
}

// Add simple charts
function addSimpleCharts() {
    const rows = document.querySelectorAll('#inventory-data tr');
    rows.forEach(row => {
        const qtyCell = row.cells[4];
        if (qtyCell && !isNaN(parseInt(qtyCell.textContent))) {
            const qty = parseInt(qtyCell.textContent);
            const bar = document.createElement('div');
            bar.style.cssText = `
                display: inline-block;
                width: 40px;
                height: 8px;
                background: ${qty > 50 ? 'green' : 'red'};
                margin-left: 5px;
            `;
            qtyCell.appendChild(bar);
        }
    });
}

// Add simple chat
function addChatWidget() {
    const chat = document.createElement('div');
    chat.innerHTML = '💬 Chat';
    chat.style.cssText = `
        position: fixed;
        bottom: 20px;
        right: 20px;
        background: blue;
        color: white;
        padding: 10px;
        border-radius: 5px;
        cursor: pointer;
    `;

    chat.addEventListener('click', () => {
        alert('Chat feature activated! You can now get help with your inventory.');
    });

    document.body.appendChild(chat);
}

// Initialize when page loads
if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
} else {
    init();
}

Save the updated content.js file.

Step 7: Upload the Updated Version

The process to update is the same as the initial upload. Go back to the "Extensions" tab in your Webfuse space and upload the inventory-modernization folder again. Webfuse will automatically replace the old version with your new one.

Refresh the page, and you will now see both modernizations active: the visual stock indicators in the table and the floating chat widget in the corner.

The Bigger Picture

In just a few steps, we have taken a basic legacy application and added two major improvements, enhancing both its usability and functionality. This example only scratches the surface of what is possible.

The simple alert in our chat widget could be replaced with code that opens a real chat application or integrates with a service like Intercom or Zendesk. The visual indicators could be replaced with more detailed charts from a library like Chart.js. You could add new buttons that trigger internal workflows, pre-fill complex forms, or pull in data from other systems.

By combining custom extensions with Webfuse's pre-built Apps like Audit Log or Session Recording, you can also add a layer of security and compliance to legacy systems that never had it. This method of web augmentation provides a practical and efficient strategy to extend the life and value of your existing software, allowing you to adapt to new business needs without the heavy cost and risk of a full migration.