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

86.04% Statements 370/430
86.27% Branches 88/102
87.5% Functions 14/16
85.74% Lines 361/421

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 4222x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 678x 326x 326x 326x 326x 326x 326x 332x 326x 326x 326x 326x 332x 326x 326x 326x 326x 326x 326x 678x 2x 2x 2x 2x 2x 2x 22x 22x 22x 22x 17x 17x 17x 2x 2x 2x 2x 2x 2x 4x 4x 4x 4x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1452x 1452x 1452x 1452x 1452x 1452x 215x 215x 215x 14x 14x 14x 14x 14x 14x 14x 14x 215x 1438x 1452x 1039x 1452x 3x 3x 3x 1039x 1448x 660x 1452x 379x 379x 1452x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1x 1x 1x 1x 1x 1x 1x     1x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 406x 406x 406x 406x 359x 44x 44x 359x 173x 406x 1x 1x 406x 406x 406x 406x 406x 406x 406x 406x 406x 406x 406x 774x 774x 774x 774x 559x 559x 559x 559x 774x 521x 774x 51x 51x 51x 51x 51x 51x 51x 2x 2x 2x 51x 51x                   51x 51x 51x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x     51x 45x 45x 45x 45x 51x 774x 42x 42x 470x 24x 428x 4x 404x 58x 58x 400x 342x 342x 314x 314x 314x 342x 342x 82x   82x 82x 82x 82x 342x 256x 10x 10x 10x 256x 256x 256x 342x 774x 406x 406x 406x 406x 233x 233x 231x 6x 6x 6x 6x 233x 233x 406x 406x 406x 2x 2x 2x 2x 2x 2x 2x 2x 49x                         49x 49x 49x 49x 49x 49x 49x 49x 49x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 24x 24x 24x 24x 24x 24x 24x 24x 45x 45x 45x 2252x 1879x 1879x 2252x 45x 45x 45x 24x 24x 24x 2x 2x 2x 2x 2x 2x 14x 14x 14x 14x 1x 1x 1x 1x 1x 1x 1x 2x 2x 2x 2x 2x 2x 14x 14x 1x 1x 2x 2x       2x 2x 2x 2x 2x 2x                                     2x 2x 2x 2x 2x 2x 4x 4x 4x 4x 4x                           4x  
import { DEV } from 'esm-env';
import { hydrating } from '../hydration.js';
import { get_descriptors, get_prototype_of, map_get, map_set } from '../../utils.js';
import {
	AttributeAliases,
	DelegatedEvents,
	is_capture_event,
	namespace_svg
} from '../../../../constants.js';
import { create_event, delegate } from './events.js';
import { add_form_reset_listener, autofocus } from './misc.js';
import * as w from '../../warnings.js';
import { LOADING_ATTR_SYMBOL } from '../../constants.js';
import { queue_idle_task, queue_micro_task } from '../task.js';
 
/**
 * The value/checked attribute in the template actually corresponds to the defaultValue property, so we need
 * to remove it upon hydration to avoid a bug when someone resets the form value.
 * @param {HTMLInputElement} dom
 * @returns {void}
 */
export function remove_input_attr_defaults(dom) {
	if (hydrating) {
		let already_removed = false;
		// We try and remove the default attributes later, rather than sync during hydration.
		// Doing it sync during hydration has a negative impact on performance, but deferring the
		// work in an idle task alleviates this greatly. If a form reset event comes in before
		// the idle callback, then we ensure the input defaults are cleared just before.
		const remove_defaults = () => {
			if (already_removed) return;
			already_removed = true;
			const value = dom.getAttribute('value');
			set_attribute(dom, 'value', null);
			set_attribute(dom, 'checked', null);
			if (value) dom.value = value;
		};
		// @ts-expect-error
		dom.__on_r = remove_defaults;
		queue_idle_task(remove_defaults);
		add_form_reset_listener();
	}
}
 
/**
 * @param {Element} element
 * @param {any} value
 */
export function set_value(element, value) {
	// @ts-expect-error
	var attributes = (element.__attributes ??= {});
 
	if (attributes.value === (attributes.value = value)) return;
	// @ts-expect-error
	element.value = value;
}
 
/**
 * @param {Element} element
 * @param {boolean} checked
 */
export function set_checked(element, checked) {
	// @ts-expect-error
	var attributes = (element.__attributes ??= {});
 
	if (attributes.checked === (attributes.checked = checked)) return;
	// @ts-expect-error
	element.checked = checked;
}
 
/**
 * @param {Element} element
 * @param {string} attribute
 * @param {string | null} value
 */
export function set_attribute(element, attribute, value) {
	value = value == null ? null : value + '';
 
	// @ts-expect-error
	var attributes = (element.__attributes ??= {});
 
	if (hydrating) {
		attributes[attribute] = element.getAttribute(attribute);
 
		if (attribute === 'src' || attribute === 'href' || attribute === 'srcset') {
			check_src_in_dev_hydration(element, attribute, value);
 
			// If we reset these attributes, they would result in another network request, which we want to avoid.
			// We assume they are the same between client and server as checking if they are equal is expensive
			// (we can't just compare the strings as they can be different between client and server but result in the
			// same url, so we would need to create hidden anchor elements to compare them)
			return;
		}
	}
 
	if (attributes[attribute] === (attributes[attribute] = value)) return;
 
	if (attribute === 'loading') {
		// @ts-expect-error
		element[LOADING_ATTR_SYMBOL] = value;
	}
 
	if (value === null) {
		element.removeAttribute(attribute);
	} else {
		element.setAttribute(attribute, value);
	}
}
 
/**
 * @param {Element} dom
 * @param {string} attribute
 * @param {string} value
 */
export function set_xlink_attribute(dom, attribute, value) {
	dom.setAttributeNS('http://www.w3.org/1999/xlink', attribute, value);
}
 
/**
 * @param {any} node
 * @param {string} prop
 * @param {any} value
 */
export function set_custom_element_data(node, prop, value) {
	if (prop in node) {
		var curr_val = node[prop];
		var next_val = typeof curr_val === 'boolean' && value === '' ? true : value;
		if (typeof curr_val !== 'object' || curr_val !== next_val) {
			node[prop] = next_val;
		}
	} else {
		set_attribute(node, prop, value);
	}
}
 
/**
 * Spreads attributes onto a DOM element, taking into account the currently set attributes
 * @param {Element & ElementCSSInlineStyle} element
 * @param {Record<string, any> | undefined} prev
 * @param {Record<string, any>} next New attributes - this function mutates this object
 * @param {boolean} lowercase_attributes
 * @param {string} css_hash
 * @returns {Record<string, any>}
 */
export function set_attributes(element, prev, next, lowercase_attributes, css_hash) {
	var has_hash = css_hash.length !== 0;
	var current = prev || {};
 
	for (var key in prev) {
		if (!(key in next)) {
			next[key] = null;
		}
	}
 
	if (has_hash && !next.class) {
		next.class = '';
	}
 
	var setters = map_get(setters_cache, element.nodeName);
	if (!setters) map_set(setters_cache, element.nodeName, (setters = get_setters(element)));
 
	// @ts-expect-error
	var attributes = /** @type {Record<string, unknown>} **/ (element.__attributes ??= {});
	/** @type {Array<[string, any, () => void]>} */
	var events = [];
 
	// since key is captured we use const
	for (const key in next) {
		// let instead of var because referenced in a closure
		let value = next[key];
		var prev_value = current[key];
		if (value === prev_value) continue;
 
		current[key] = value;
 
		var prefix = key[0] + key[1]; // this is faster than key.slice(0, 2)
		if (prefix === '$$') continue;
 
		if (prefix === 'on') {
			/** @type {{ capture?: true }} */
			const opts = {};
			const event_handle_key = '$$' + key;
			let event_name = key.slice(2);
			var delegated = DelegatedEvents.includes(event_name);
 
			if (is_capture_event(event_name)) {
				event_name = event_name.slice(0, -7);
				opts.capture = true;
			}
 
			if (!delegated && prev_value) {
				// Listening to same event but different handler -> our handle function below takes care of this
				// If we were to remove and add listeners in this case, it could happen that the event is "swallowed"
				// (the browser seems to not know yet that a new one exists now) and doesn't reach the handler
				// https://github.com/sveltejs/svelte/issues/11903
				if (value != null) continue;

				element.removeEventListener(event_name, current[event_handle_key], opts);
				current[event_handle_key] = null;
			}
 
			if (value != null) {
				if (!delegated) {
					/**
					 * @this {any}
					 * @param {Event} evt
					 */
					function handle(evt) {
						current[key].call(this, evt);
					}
 
					if (!prev) {
						events.push([
							key,
							value,
							() => (current[event_handle_key] = create_event(event_name, element, handle, opts))
						]);
					} else {
						current[event_handle_key] = create_event(event_name, element, handle, opts);
					}
				} else {
					// @ts-ignore
					element[`__${event_name}`] = value;
					delegate([event_name]);
				}
			}
		} else if (value == null) {
			attributes[key] = null;
			element.removeAttribute(key);
		} else if (key === 'style') {
			element.style.cssText = value + '';
		} else if (key === 'autofocus') {
			autofocus(/** @type {HTMLElement} */ (element), Boolean(value));
		} else if (key === '__value' || key === 'value') {
			// @ts-ignore
			element.value = element[key] = element.__value = value;
		} else {
			var name = key;
			if (lowercase_attributes) {
				name = name.toLowerCase();
				name = AttributeAliases[name] || name;
			}
 
			if (setters.includes(name)) {
				if (hydrating && (name === 'src' || name === 'href' || name === 'srcset')) {
					check_src_in_dev_hydration(element, name, value);
				} else {
					// @ts-ignore
					element[name] = value;
				}
			} else if (typeof value !== 'function') {
				if (has_hash && name === 'class') {
					if (value) value += ' ';
					value += css_hash;
				}
 
				set_attribute(element, name, value);
			}
		}
	}
 
	// On the first run, ensure that events are added after bindings so
	// that their listeners fire after the binding listeners
	if (!prev) {
		queue_micro_task(() => {
			if (!element.isConnected) return;
			for (const [key, value, evt] of events) {
				if (current[key] === value) {
					evt();
				}
			}
		});
	}
 
	return current;
}
 
/**
 * @param {Element} node
 * @param {Record<string, any> | undefined} prev
 * @param {Record<string, any>} next The new attributes - this function mutates this object
 * @param {string} css_hash
 */
export function set_dynamic_element_attributes(node, prev, next, css_hash) {
	if (node.tagName.includes('-')) {
		for (var key in prev) {
			if (!(key in next)) {
				next[key] = null;
			}
		}

		for (key in next) {
			set_custom_element_data(node, key, next[key]);
		}

		return next;
	}
 
	return set_attributes(
		/** @type {Element & ElementCSSInlineStyle} */ (node),
		prev,
		next,
		node.namespaceURI !== namespace_svg,
		css_hash
	);
}
 
/**
 * List of attributes that should always be set through the attr method,
 * because updating them through the property setter doesn't work reliably.
 * In the example of `width`/`height`, the problem is that the setter only
 * accepts numeric values, but the attribute can also be set to a string like `50%`.
 * If this list becomes too big, rethink this approach.
 */
var always_set_through_set_attribute = ['width', 'height'];
 
/** @type {Map<string, string[]>} */
var setters_cache = new Map();
 
/** @param {Element} element */
function get_setters(element) {
	/** @type {string[]} */
	var setters = [];
	var descriptors;
	var proto = get_prototype_of(element);
 
	// Stop at Element, from there on there's only unnecessary setters we're not interested in
	while (proto.constructor.name !== 'Element') {
		descriptors = get_descriptors(proto);
 
		for (var key in descriptors) {
			if (descriptors[key].set && !always_set_through_set_attribute.includes(key)) {
				setters.push(key);
			}
		}
 
		proto = get_prototype_of(proto);
	}
 
	return setters;
}
 
/**
 * @param {any} element
 * @param {string} attribute
 * @param {string | null} value
 */
function check_src_in_dev_hydration(element, attribute, value) {
	if (!DEV) return;
	if (attribute === 'srcset' && srcset_url_equal(element, value)) return;
	if (src_url_equal(element.getAttribute(attribute) ?? '', value ?? '')) return;
 
	w.hydration_attribute_changed(
		attribute,
		element.outerHTML.replace(element.innerHTML, '...'),
		String(value)
	);
}
 
/**
 * @param {string} element_src
 * @param {string} url
 * @returns {boolean}
 */
function src_url_equal(element_src, url) {
	if (element_src === url) return true;
	return new URL(element_src, document.baseURI).href === new URL(url, document.baseURI).href;
}
 
/** @param {string} srcset */
function split_srcset(srcset) {
	return srcset.split(',').map((src) => src.trim().split(' ').filter(Boolean));
}
 
/**
 * @param {HTMLSourceElement | HTMLImageElement} element
 * @param {string | undefined | null} srcset
 * @returns {boolean}
 */
function srcset_url_equal(element, srcset) {
	var element_urls = split_srcset(element.srcset);
	var urls = split_srcset(srcset ?? '');

	return (
		urls.length === element_urls.length &&
		urls.every(
			([url, width], i) =>
				width === element_urls[i][1] &&
				// We need to test both ways because Vite will create an a full URL with
				// `new URL(asset, import.meta.url).href` for the client when `base: './'`, and the
				// relative URLs inside srcset are not automatically resolved to absolute URLs by
				// browsers (in contrast to img.src). This means both SSR and DOM code could
				// contain relative or absolute URLs.
				(src_url_equal(element_urls[i][0], url) || src_url_equal(url, element_urls[i][0]))
		)
	);
}
 
/**
 * @param {HTMLImageElement} element
 * @returns {void}
 */
export function handle_lazy_img(element) {
	// If we're using an image that has a lazy loading attribute, we need to apply
	// the loading and src after the img element has been appended to the document.
	// Otherwise the lazy behaviour will not work due to our cloneNode heuristic for
	// templates.
	if (!hydrating && element.loading === 'lazy') {
		var src = element.src;
		// @ts-expect-error
		element[LOADING_ATTR_SYMBOL] = null;
		element.loading = 'eager';
		element.removeAttribute('src');
		requestAnimationFrame(() => {
			// @ts-expect-error
			if (element[LOADING_ATTR_SYMBOL] !== 'eager') {
				element.loading = 'lazy';
			}
			element.src = src;
		});
	}
}