All files / src/internal/client/dom/elements events.js

93.7% Statements 253/270
85.18% Branches 46/54
100% Functions 8/8
93.58% Lines 248/265

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 2662x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1x 1x 1x 1x 1x 1x 1x 1x 1x 2x                 2x 2x 2x 2x 2x 2x 2x 2x 2x 3167x 3167x 3167x 3167x 1186x 1180x 1180x 1180x 1186x 1183x 1183x 1186x 3167x 3167x 3167x 3167x 3167x 3167x       3167x 3167x 3167x 3167x 3167x 3167x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 4x 4x 4x 1x 4x 4x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 3157x 3157x 3157x 3157x 3157x 28x 28x 28x 28x 3157x 2x 2x 2x 2x 2x 2x 172x 175x 175x 172x 172x 670x 670x 172x 2x 2x 2x 2x 2x 2x 2x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 260564x 258529x 258529x 258529x 258523x 258529x 258486x 258486x 258486x 258486x 258486x 258486x 258486x 43x 43x 43x 43x 43x 43x 43x 258529x 6x 6x 6x 6x 37x 258529x 9x 9x 258529x 2072x 260564x 260564x 260564x 260564x 260564x 932x 932x 932x 932x 932x 2x 2x 932x 932x 932x 932x 932x 932x 932x 932x 932x 932x 932x 932x 257998x 991x 991x 991x 991x 991x 991x 991x 991x 991x 486x 342x 342x 486x 144x 144x 486x 991x 2x   2x 2x 2x 2x 991x 932x 932x 59x 59x 932x 260563x 2x           2x 2x 260564x 932x 932x 932x 932x 932x 260564x  
import { teardown } from '../../reactivity/effects.js';
import { all_registered_events, root_event_handles } from '../../render.js';
import { define_property, is_array } from '../../utils.js';
import { hydrating } from '../hydration.js';
import { queue_micro_task } from '../task.js';
 
/**
 * SSR adds onload and onerror attributes to catch those events before the hydration.
 * This function detects those cases, removes the attributes and replays the events.
 * @param {HTMLElement} dom
 */
export function replay_events(dom) {
	if (!hydrating) return;
 
	if (dom.onload) {
		dom.removeAttribute('onload');
	}
	if (dom.onerror) {
		dom.removeAttribute('onerror');
	}
	// @ts-expect-error
	const event = dom.__e;
	if (event !== undefined) {
		// @ts-expect-error
		dom.__e = undefined;
		queueMicrotask(() => {
			if (dom.isConnected) {
				dom.dispatchEvent(event);
			}
		});
	}
}
 
/**
 * @param {string} event_name
 * @param {EventTarget} dom
 * @param {EventListener} handler
 * @param {AddEventListenerOptions} options
 */
export function create_event(event_name, dom, handler, options) {
	/**
	 * @this {EventTarget}
	 */
	function target_handler(/** @type {Event} */ event) {
		if (!options.capture) {
			// Only call in the bubble phase, else delegated events would be called before the capturing events
			handle_event_propagation(dom, event);
		}
		if (!event.cancelBubble) {
			return handler.call(this, event);
		}
	}
 
	// Chrome has a bug where pointer events don't work when attached to a DOM element that has been cloned
	// with cloneNode() and the DOM element is disconnected from the document. To ensure the event works, we
	// defer the attachment till after it's been appended to the document. TODO: remove this once Chrome fixes
	// this bug. The same applies to wheel events.
	if (event_name.startsWith('pointer') || event_name === 'wheel') {
		queue_micro_task(() => {
			dom.addEventListener(event_name, target_handler, options);
		});
	} else {
		dom.addEventListener(event_name, target_handler, options);
	}
 
	return target_handler;
}
 
/**
 * Attaches an event handler to an element and returns a function that removes the handler. Using this
 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
 * (with attributes like `onclick`), which use event delegation for performance reasons
 *
 * @template {HTMLElement} Element
 * @template {keyof HTMLElementEventMap} Type
 * @overload
 * @param {Element} element
 * @param {Type} type
 * @param {(this: Element, event: HTMLElementEventMap[Type]) => any} handler
 * @param {AddEventListenerOptions} [options]
 * @returns {() => void}
 */
 
/**
 * Attaches an event handler to an element and returns a function that removes the handler. Using this
 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
 * (with attributes like `onclick`), which use event delegation for performance reasons
 *
 * @overload
 * @param {EventTarget} element
 * @param {string} type
 * @param {EventListener} handler
 * @param {AddEventListenerOptions} [options]
 * @returns {() => void}
 */
 
/**
 * @param {EventTarget} element
 * @param {string} type
 * @param {EventListener} handler
 * @param {AddEventListenerOptions} [options]
 */
export function on(element, type, handler, options = {}) {
	var target_handler = create_event(type, element, handler, options);
 
	return () => {
		element.removeEventListener(type, target_handler, options);
	};
}
 
/**
 * @param {string} event_name
 * @param {Element} dom
 * @param {EventListener} handler
 * @param {boolean} capture
 * @param {boolean} [passive]
 * @returns {void}
 */
export function event(event_name, dom, handler, capture, passive) {
	var options = { capture, passive };
	var target_handler = create_event(event_name, dom, handler, options);
 
	// @ts-ignore
	if (dom === document.body || dom === window || dom === document) {
		teardown(() => {
			dom.removeEventListener(event_name, target_handler, options);
		});
	}
}
 
/**
 * @param {Array<string>} events
 * @returns {void}
 */
export function delegate(events) {
	for (var i = 0; i < events.length; i++) {
		all_registered_events.add(events[i]);
	}
 
	for (var fn of root_event_handles) {
		fn(events);
	}
}
 
/**
 * @param {EventTarget} handler_element
 * @param {Event} event
 * @returns {void}
 */
export function handle_event_propagation(handler_element, event) {
	var owner_document = /** @type {Node} */ (handler_element).ownerDocument;
	var event_name = event.type;
	var path = event.composedPath?.() || [];
	var current_target = /** @type {null | Element} */ (path[0] || event.target);
 
	// composedPath contains list of nodes the event has propagated through.
	// We check __root to skip all nodes below it in case this is a
	// parent of the __root node, which indicates that there's nested
	// mounted apps. In this case we don't want to trigger events multiple times.
	var path_idx = 0;
 
	// @ts-expect-error is added below
	var handled_at = event.__root;
 
	if (handled_at) {
		var at_idx = path.indexOf(handled_at);
		if (
			at_idx !== -1 &&
			(handler_element === document || handler_element === /** @type {any} */ (window))
		) {
			// This is the fallback document listener or a window listener, but the event was already handled
			// -> ignore, but set handle_at to document/window so that we're resetting the event
			// chain in case someone manually dispatches the same event object again.
			// @ts-expect-error
			event.__root = handler_element;
			return;
		}
 
		// We're deliberately not skipping if the index is higher, because
		// someone could create an event programmatically and emit it multiple times,
		// in which case we want to handle the whole propagation chain properly each time.
		// (this will only be a false negative if the event is dispatched multiple times and
		// the fallback document listener isn't reached in between, but that's super rare)
		var handler_idx = path.indexOf(handler_element);
		if (handler_idx === -1) {
			// handle_idx can theoretically be -1 (happened in some JSDOM testing scenarios with an event listener on the window object)
			// so guard against that, too, and assume that everything was handled at this point.
			return;
		}
 
		if (at_idx <= handler_idx) {
			path_idx = at_idx;
		}
	}
 
	current_target = /** @type {Element} */ (path[path_idx] || event.target);
	// there can only be one delegated event per element, and we either already handled the current target,
	// or this is the very first target in the chain which has a non-delegated listener, in which case it's safe
	// to handle a possible delegated event on it later (through the root delegation listener for example).
	if (current_target === handler_element) return;
 
	// Proxy currentTarget to correct target
	define_property(event, 'currentTarget', {
		configurable: true,
		get() {
			return current_target || owner_document;
		}
	});
 
	try {
		/**
		 * @type {unknown}
		 */
		var throw_error;
		/**
		 * @type {unknown[]}
		 */
		var other_errors = [];
 
		while (current_target !== null) {
			/** @type {null | Element} */
			var parent_element =
				current_target.parentNode || /** @type {any} */ (current_target).host || null;
 
			try {
				// @ts-expect-error
				var delegated = current_target['__' + event_name];
 
				if (delegated !== undefined && !(/** @type {any} */ (current_target).disabled)) {
					if (is_array(delegated)) {
						var [fn, ...data] = delegated;
						fn.apply(current_target, [event, ...data]);
					} else {
						delegated.call(current_target, event);
					}
				}
			} catch (error) {
				if (throw_error) {
					other_errors.push(error);
				} else {
					throw_error = error;
				}
			}
			if (event.cancelBubble || parent_element === handler_element || parent_element === null) {
				break;
			}
			current_target = parent_element;
		}
 
		if (throw_error) {
			for (let error of other_errors) {
				// Throw the rest of the errors, one-by-one on a microtask
				queueMicrotask(() => {
					throw error;
				});
			}
			throw throw_error;
		}
	} finally {
		// @ts-expect-error is used above
		event.__root = handler_element;
		// @ts-expect-error is used above
		current_target = handler_element;
	}
}