prepare_element_spread() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js lines 416–473

export function prepare_element_spread(
	element,
	attributes,
	style_directives,
	class_directives,
	context,
	transform
) {
	/** @type {ObjectExpression | undefined} */
	let classes;
	/** @type {ObjectExpression | undefined} */
	let styles;
	let flags = 0;

	if (class_directives.length) {
		const properties = class_directives.map((directive) =>
			b.init(
				directive.name,
				directive.expression.type === 'Identifier' && directive.expression.name === directive.name
					? b.id(directive.name)
					: transform(
							/** @type {Expression} */ (context.visit(directive.expression)),
							directive.metadata.expression
						)
			)
		);

		classes = b.object(properties);
	}

	if (style_directives.length > 0) {
		const properties = style_directives.map((directive) =>
			b.init(
				directive.name,
				directive.value === true
					? b.id(directive.name)
					: build_attribute_value(directive.value, context, transform, true)
			)
		);
		styles = b.object(properties);
	}

	if (element.metadata.svg || element.metadata.mathml) {
		flags |= ELEMENT_IS_NAMESPACED | ELEMENT_PRESERVE_ATTRIBUTE_CASE;
	} else if (is_custom_element_node(element)) {
		flags |= ELEMENT_PRESERVE_ATTRIBUTE_CASE;
	} else if (element.type === 'RegularElement' && element.name === 'input') {
		flags |= ELEMENT_IS_INPUT;
	}

	const object = build_spread_object(element, attributes, context, transform);
	const css_hash =
		element.metadata.scoped && context.state.analysis.css.hash
			? b.literal(context.state.analysis.css.hash)
			: undefined;

	return [object, css_hash, classes, styles, flags ? b.literal(flags) : undefined];
}