EventEmitter - Event-Driven Architecture

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// Create an event emitter
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dhoro emitter = ghotona_srishti();
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dekho(emitter);  // EventEmitter(events=0, listeners=0)

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dhoro emitter = ghotona_srishti();
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// Add a listener
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ghotona_shuno(emitter, "message", kaj(data) {
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    dekho("Received:", data);
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});
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// Emit the event multiple times
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ghotona_prokash(emitter, "message", "Hello");  // Received: Hello
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ghotona_prokash(emitter, "message", "World");  // Received: World

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dhoro emitter = ghotona_srishti();
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// Add a one-time listener
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ghotona_ekbar(emitter, "startup", kaj() {
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    dekho("Application started!");
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});
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// Emit multiple times - listener only runs once
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ghotona_prokash(emitter, "startup");  // Application started!
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ghotona_prokash(emitter, "startup");  // (no output - listener already removed)

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dhoro emitter = ghotona_srishti();
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ghotona_shuno(emitter, "user:login", kaj(username, time) {
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    dekho(username + " logged in at " + time);
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});
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// Emit with multiple data arguments
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ghotona_prokash(emitter, "user:login", "Ankan", "09:30 AM");
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// Output: Ankan logged in at 09:30 AM

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dhoro emitter = ghotona_srishti();
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// First listener
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ghotona_shuno(emitter, "data", kaj(value) {
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    dekho("Listener 1:", value);
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});
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// Second listener
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ghotona_shuno(emitter, "data", kaj(value) {
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    dekho("Listener 2:", value * 2);
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});
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ghotona_prokash(emitter, "data", 10);
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// Output:
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// Listener 1: 10
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// Listener 2: 20

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dhoro emitter = ghotona_srishti();
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// Store listener reference
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dhoro listener = kaj(msg) {
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    dekho("Received:", msg);
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};
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ghotona_shuno(emitter, "update", listener);
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ghotona_prokash(emitter, "update", "First");  // Received: First
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// Remove the listener
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ghotona_bondho(emitter, "update", listener);
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ghotona_prokash(emitter, "update", "Second");  // (no output)

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dhoro emitter = ghotona_srishti();
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ghotona_shuno(emitter, "event1", kaj() { dekho("Event 1"); });
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ghotona_shuno(emitter, "event2", kaj() { dekho("Event 2"); });
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// Remove all listeners for "event1"
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ghotona_sob_bondho(emitter, "event1");
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// Remove all listeners for all events
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ghotona_sob_bondho(emitter);

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dhoro emitter = ghotona_srishti();
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ghotona_shuno(emitter, "test", kaj() { });
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ghotona_shuno(emitter, "test", kaj() { });
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dhoro listeners = ghotona_shrotara(emitter, "test");
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dekho("Number of listeners:", dorghyo(listeners));  // 2

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dhoro emitter = ghotona_srishti();
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ghotona_shuno(emitter, "event1", kaj() { });
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ghotona_shuno(emitter, "event2", kaj() { });
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ghotona_shuno(emitter, "event3", kaj() { });
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dhoro events = ghotona_naam_sob(emitter);
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dekho("Events:", events);  // ["event1", "event2", "event3"]

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dhoro emitter = ghotona_srishti();
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ghotona_shuno(emitter, "start", kaj() { dekho("Starting..."); })
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ghotona_shuno(emitter, "process", kaj() { dekho("Processing..."); })
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ghotona_shuno(emitter, "end", kaj() { dekho("Done!"); });
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// Chain emit calls
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ghotona_prokash(emitter, "start");
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ghotona_prokash(emitter, "process");
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ghotona_prokash(emitter, "end");

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// Create a message bus for pub/sub
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dhoro messageBus = ghotona_srishti();
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// Subscribe to messages
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ghotona_shuno(messageBus, "notification", kaj(msg) {
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    dekho("[NOTIFICATION]", msg);
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});
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ghotona_shuno(messageBus, "error", kaj(err) {
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    dekho("[ERROR]", err);
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});
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// Publish messages
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ghotona_prokash(messageBus, "notification", "User logged in");
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ghotona_prokash(messageBus, "error", "Database connection failed");

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// Simple task queue with events
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dhoro taskQueue = ghotona_srishti();
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dhoro tasks = [];
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// Listen for task:add event
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ghotona_shuno(taskQueue, "task:add", kaj(task) {
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    dhokao(tasks, task);
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    dekho("Task added:", task["name"]);
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    ghotona_prokash(taskQueue, "task:count", dorghyo(tasks));
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});
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// Listen for task count updates
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ghotona_shuno(taskQueue, "task:count", kaj(count) {
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    dekho("Total tasks:", count);
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});
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// Add tasks
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ghotona_prokash(taskQueue, "task:add", {"name": "Send email"});
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ghotona_prokash(taskQueue, "task:add", {"name": "Process payment"});
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ghotona_prokash(taskQueue, "task:add", {"name": "Update database"});

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// Simple state manager with events
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dhoro stateManager = ghotona_srishti();
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dhoro state = {"count": 0};
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// Listen for state changes
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ghotona_shuno(stateManager, "state:change", kaj(newState) {
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    state = newState;
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    dekho("State updated:", state);
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});
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// Listen for specific actions
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ghotona_shuno(stateManager, "increment", kaj() {
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    state["count"] = state["count"] + 1;
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    ghotona_prokash(stateManager, "state:change", state);
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});
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ghotona_shuno(stateManager, "decrement", kaj() {
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    state["count"] = state["count"] - 1;
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    ghotona_prokash(stateManager, "state:change", state);
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});
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// Trigger actions
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ghotona_prokash(stateManager, "increment");  // count: 1
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ghotona_prokash(stateManager, "increment");  // count: 2
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ghotona_prokash(stateManager, "decrement");  // count: 1