Content:

• Day 0: Getting Started with cshttp
• Day 1: Multi-Page Routing (Home, About, Contact & 404)
• Day 2: Clean Templates & Dynamic Content (Shared Layout)
• Day 3: Accepting User Input (URL Query String & GET Forms)
• Day 4: Handling Forms & Submissions (HTTP POST)
• Day 5: Dynamic Data & Memory State (Interactive Guestbook)

Day 2: Clean Templates & Dynamic Content (Shared Layout)

In Day 1, notice how every single method (HandleHome, HandleAbout, HandleContact) had to repeat the entire <html>, <head>, <body>, and navigation menu over and over again.

If we wanted to change a navigation link, we would have had to update 4 different places!

In Day 2, we introduce Templates. We create one single master layout method called RenderPage(...) that wraps all our pages automatically, and we insert dynamic server data (the real-time server clock) using C# string interpolation ($"").

What You Will Learn Today

1. RenderPage(title, bodyContent): A reusable master layout function that generates the header, navigation bar, and footer once for the whole website.
2. String Interpolation ($""): Injecting C# variables directly into HTML strings using {variableName}.
3. Dynamic Server Time: Displaying DateTime.Now live in the footer on every page refresh.

The Code

Update Program.cs with the following code:

using System;
using cshttp;

static class Program
{
    static void Main()
    {
        WebApp.Run(8080, OnRequest);
    }

    static void OnRequest()
    {
        string path = Request.Path.ToLower();

        switch (path)
        {
            case "/":
            case "/home":
                HandleHome();
                return;
            case "/about":
                HandleAbout();
                return;
            case "/contact":
                HandleContact();
                return;
            default:
                HandleNotFound();
                return;
        }
    }

    // NEW IN DAY 2: One shared template for the whole website
    static void RenderPage(string title, string bodyContent)
    {
        string html = $@"
<html>
    <head>
        <title>{title}</title>
    </head>
    <body>
        <nav>
            <a href=""/"">Home</a> | 
            <a href=""/about"">About</a> | 
            <a href=""/contact"">Contact</a>
        </nav>
        <hr />
        
        {bodyContent}

        <hr />
        <footer>
            <small>Server Time: {DateTime.Now:yyyy-MM-dd HH:mm:ss}</small>
        </footer>
    </body>
</html>";

        Response.Write(html);
        Response.End();
    }

    static void HandleHome()
    {
        string content = @"
            <h1>Welcome Home</h1>
            <p>Refresh the page and watch the server clock at the bottom change!</p>";

        RenderPage("Home", content);
    }

    static void HandleAbout()
    {
        string content = @"
            <h1>About Us</h1>
            <p>We build fast, zero-dependency web apps in C#.</p>";

        RenderPage("About Us", content);
    }

    static void HandleContact()
    {
        string content = @"
            <h1>Contact</h1>
            <p>Email us at [email protected]</p>";

        RenderPage("Contact", content);
    }

    static void HandleNotFound()
    {
        Response.StatusCode = 404;
        string content = @"
            <h1>404 Not Found</h1>
            <p>The page you are looking for does not exist.</p>";

        RenderPage("404 Not Found", content);
    }
}

Test It in Your Browser

1. Run the app (dotnet run).
2. Visit http://localhost:8080/.
3. Notice the navigation bar at the top and the Server Time at the bottom.
4. Refresh the page several times—the time updates on every request because the C# code executes live on the server!