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43 lines
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<!doctype html>
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<head>
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<meta charset="utf-8">
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<meta name="viewport" content="width=device-width, initial-scale=1">
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<title>@On — Ludic</title>
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<meta name="description" content="Register a compile-time listener that runs whenever an event is emitted.">
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<link rel="stylesheet" href="base.css">
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<link rel="stylesheet" href="docs.css">
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</head>
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<body>
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<header class="nav"><div class="wrap nav-in"><a class="brand" href="index.html"><span class="logo">L</span> Ludic</a><button class="nav-toggle" aria-label="Toggle menu" aria-expanded="false">☰</button><nav class="nav-links"><a href="index.html">Home</a><a href="api.html">API Reference</a><a class="nav-cta" href="https://git.workshopsoft.io/workshopsoft/ludic">Source ↗</a></nav></div></header>
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<main class="wrap item">
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<div class="crumbs"><a href="api.html">API Reference</a> <span>›</span> <a href="api.html#annotations">Annotations</a> <span>›</span> <span class="here">@On</span></div>
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<div class="item-head">
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<span class="kind-badge kind-annotation">annotation</span>
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<h1 id="top">@On</h1>
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</div>
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<code class="sig">@On(Event) handler Name { … }</code>
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<div class="desc"><p><code>@On(Event)</code> turns a handler into a listener for a named <code>event</code>: whenever any code runs <code>emit Event(...)</code>, this handler's body runs with the event's fields bound by name. It is how systems talk to each other without referencing one another directly — the emitter never knows who is listening, so gameplay, UI and mods can all react to the same moment independently. Several handlers may listen to one event; they run in declaration order. On a <code>cancellable event</code>, a listener may <code>cancel</code> to veto it, and the emitter sees that outcome. Related lifecycle hooks such as <code>@OnSpawn</code>, <code>@OnEnable</code> and <code>@OnDespawn</code> are specialized event listeners the compiler wires up for you.</p></div>
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<div class="examples"><h2>Example</h2><pre data-lang="ludic">program Events {
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property Health { current: int = 100, maximum: int = 100 }
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model Player { Health }
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event Damaged { amount: int = 0 }
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handler SpawnPlayer phase Start {
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spawn Player { Health { current: 100, maximum: 100 } }
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emit Damaged(amount: 25)
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}
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@On(Damaged)
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handler ReportDamage {
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print(amount)
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}
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}</pre></div>
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<a class="back" href="api.html">← All symbols</a>
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</main>
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<script src="ludic-highlight.js"></script>
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<script>Ludic.highlightAll(); Ludic.installCards(); Ludic.flashTarget();</script>
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</body></html> |