Tilo15
/
Spry


			
				
					
						
						
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							using Astralis;
using Invercargill;
using Invercargill.DataStructures;
using Inversion;
using Spry;

/**
 * ProgressExample demonstrates the continuation feature for server-sent events (SSE).
 * 
 * The continuation feature allows a Component to send real-time progress updates
 * to the client via SSE. This is useful for:
 * - Long-running task progress reporting
 * - Real-time status updates
 * - Live data streaming
 * 
 * How it works:
 * 1. Add `spry-continuation` attribute to an element in your markup
 *    (This is shorthand for: hx-ext="sse" sse-connect="(endpoint)" sse-close="_spry-close")
 * 2. Use `sse-swap="eventname"` on child elements to swap content when events arrive
 * 3. Override the `continuation(SseStream stream)` method in your Component
 * 4. Use `stream.send_event()` to send SSE events with HTML content to swap
 */
class ProgressComponent : Component {
    
    public int percent { get; set; }
    public string status { get; set; default = "Initializing..."; }
    public Series<string> completed_tasks { get; set; default = new Series<string>(); }
    
    public override string markup { get {
        return """
        <!DOCTYPE html>
        <html>
        <head>
        <script spry-res="htmx.js"></script>
        <script spry-res="htmx-sse.js"></script>
        <style>
            body { font-family: system-ui, sans-serif; max-width: 600px; margin: 50px auto; padding: 20px; }
            .progress-container { 
                background: #e0e0e0; 
                border-radius: 8px; 
                overflow: hidden; 
                margin: 20px 0;
            }
            .progress-bar { 
                height: 30px; 
                background: linear-gradient(90deg, #4CAF50, #8BC34A); 
                transition: width 0.3s ease;
                display: flex;
                align-items: center;
                justify-content: center;
                color: white;
                font-weight: bold;
                min-width: 40px;
            }
            .status { 
                padding: 15px; 
                background: #f5f5f5; 
                border-radius: 4px; 
                margin: 10px 0;
                border-left: 4px solid #2196F3;
            }
            .log { 
                max-height: 200px; 
                overflow-y: auto; 
                background: #263238; 
                color: #4CAF50; 
                padding: 15px; 
                border-radius: 4px;
                font-family: monospace;
                font-size: 14px;
            }
            .log-entry { margin: 5px 0; }
            h1 { color: #333; }
            .info { color: #666; font-size: 14px; }
        </style>
        </head>
        <body>
        <h1>Task Progress Demo</h1>
        <p class="info">This example demonstrates Spry's continuation feature for real-time progress updates via Server-Sent Events (SSE).</p>
        
        <div spry-continuation>
            <div class="progress-container" >
                <div class="progress-bar" spry-fragment="progress-bar"
                content-expr='format("%i%%", this.percent)' style-width-expr='format("%i%%", this.percent)'>
                    0%
                </div>
            </div>
            
            <div class="status" spry-fragment="status">
                <strong>Status:</strong> <span content-expr="this.status">Initializing...</span>
            </div>
            
            <div class="log" sid="log" spry-fragment="log">
                <div spry-per-task="this.completed_tasks" content-expr="task"></div>
            </div>
        </div>
        </body>
        </html>
        """;
    }}
    
    /**
     * The continuation method is called when a client connects to the SSE endpoint.
     * This is where you can send real-time updates to the client.
     * 
     * The event data should be HTML content that will be swapped into elements
     * with matching sse-swap="eventname" attributes.
     */
    public async override void continuation(ContinuationContext continuation_context) throws Error {
        // Simulate a long-running task with progress updates
        var steps = new string[] {
            "Initializing task...",
            "Loading configuration...",
            "Connecting to database...",
            "Fetching records...",
            "Processing batch 1/5...",
            "Processing batch 2/5...",
            "Processing batch 3/5...",
            "Processing batch 4/5...",
            "Processing batch 5/5...",
            "Validating results...",
            "Generating report...",
            "Finalizing..."
        };
        
        for (int i = 0; i < steps.length; i++) {
            // Update the template
            percent = (int)(((i + 1) / (double)steps.length) * 100);
            status = steps[i];
            completed_tasks.add_start(steps[i]);
            
            // Send progress bar update - HTML that will be swapped into the progress bar
            yield continuation_context.send_fragment("progress-bar");
            
            // Send status update - HTML that will be swapped into the status div
            yield continuation_context.send_fragment("status");
            
            // Send log message - HTML that will be appended to the log
            yield continuation_context.send_fragment("log");
            
            // Simulate work being done (500ms per step)
            Timeout.add(500, () => {
                continuation.callback();
                return false;
            });
            yield;
        }
        
        // Send final completion messages
        percent = 100;
        status = "Task completed successfully!";
        yield continuation_context.send_fragment("progress-bar");
        yield continuation_context.send_fragment("status");
    }
}

class HomePageEndpoint : Object, Endpoint {

    private ProgressComponent progress_component = inject<ProgressComponent>();

    public async Astralis.HttpResult handle_request(Astralis.HttpContext http_context, Astralis.RouteContext route_context) throws Error {
        return yield progress_component.to_result();
    }
}

void main(string[] args) {
    int port = args.length > 1 ? int.parse(args[1]) : 8080;
    
    try {
        var application = new WebApplication(port);
        
        // Register compression components
        application.use_compression();
        
        // Add Spry module (includes ContinuationProvider for SSE)
        application.add_module<SpryModule>();

        // Register the progress component
        application.add_transient<ProgressComponent>();

        // Register the home page endpoint
        application.add_endpoint<HomePageEndpoint>(new EndpointRoute("/"));

        print("Progress Example running on http://localhost:%d/\n", port);
        print("Open the URL in your browser to see real-time progress updates via SSE.\n");
        
        application.run();
        
    } catch (Error e) {
        printerr("Error: %s\n", e.message);
        Process.exit(1);
    }
}