createEventDispatcher() — svelte Function Reference

Architecture documentation for the createEventDispatcher() function in index-client.js from the svelte codebase.

Function javascript SharedInternal DOMUtils calls 1

Entity Profile

SharedInternal→ DOMUtils→ createEventDispatcher() — svelte Function Reference

Dependency Diagram

graph TD
  8b5898aa_f3a9_86ef_471f_73e019323c86["createEventDispatcher()"]
  717fc8d5_bdb4_4b73_d6c5_c4a367a60cf2["index-client.js"]
  8b5898aa_f3a9_86ef_471f_73e019323c86 -->|defined in| 717fc8d5_bdb4_4b73_d6c5_c4a367a60cf2
  6f9aee52_ea1e_49b7_4d74_b070e0c04958["create_custom_event()"]
  8b5898aa_f3a9_86ef_471f_73e019323c86 -->|calls| 6f9aee52_ea1e_49b7_4d74_b070e0c04958
  style 8b5898aa_f3a9_86ef_471f_73e019323c86 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/index-client.js lines 157–185

export function createEventDispatcher() {
	const active_component_context = component_context;
	if (active_component_context === null) {
		e.lifecycle_outside_component('createEventDispatcher');
	}

	/**
	 * @param [detail]
	 * @param [options]
	 */
	return (type, detail, options) => {
		const events = /** @type {Record<string, Function | Function[]>} */ (
			active_component_context.s.$$events
		)?.[/** @type {string} */ (type)];

		if (events) {
			const callbacks = is_array(events) ? events.slice() : [events];
			// TODO are there situations where events could be dispatched
			// in a server (non-DOM) environment?
			const event = create_custom_event(/** @type {string} */ (type), detail, options);
			for (const fn of callbacks) {
				fn.call(active_component_context.x, event);
			}
			return !event.defaultPrevented;
		}

		return true;
	};
}