element.js — svelte Source File

Source Code

/** @import { Expression, Identifier, ObjectExpression } from 'estree' */
/** @import { AST } from '#compiler' */
/** @import { ComponentContext } from '../../types' */
import { escape_html } from '../../../../../../escaping.js';
import { normalize_attribute } from '../../../../../../utils.js';
import { is_ignored } from '../../../../../state.js';
import { is_event_attribute } from '../../../../../utils/ast.js';
import * as b from '#compiler/builders';
import { build_class_directives_object, build_style_directives_object } from '../RegularElement.js';
import { build_expression, build_template_chunk, Memoizer } from './utils.js';
import { ExpressionMetadata } from '../../../../nodes.js';

/**
 * @param {Array<AST.Attribute | AST.SpreadAttribute>} attributes
 * @param {AST.ClassDirective[]} class_directives
 * @param {AST.StyleDirective[]} style_directives
 * @param {ComponentContext} context
 * @param {AST.RegularElement | AST.SvelteElement} element
 * @param {Identifier} element_id
 * @param {boolean} [should_remove_defaults]
 */
export function build_attribute_effect(
	attributes,
	class_directives,
	style_directives,
	context,
	element,
	element_id,
	should_remove_defaults = false
) {
	/** @type {ObjectExpression['properties']} */
	const values = [];

	const memoizer = new Memoizer();

	for (const attribute of attributes) {
		if (attribute.type === 'Attribute') {
			const { value } = build_attribute_value(attribute.value, context, (value, metadata) =>
				memoizer.add(value, metadata)
			);

			if (
				is_event_attribute(attribute) &&
				(value.type === 'ArrowFunctionExpression' || value.type === 'FunctionExpression')
			) {
				// Give the event handler a stable ID so it isn't removed and readded on every update
				const id = context.state.scope.generate('event_handler');
				context.state.init.push(b.var(id, value));
				values.push(b.init(attribute.name, b.id(id)));
			} else {
				values.push(b.init(attribute.name, value));
			}
		} else {
			let value = /** @type {Expression} */ (context.visit(attribute));

			value = memoizer.add(value, attribute.metadata.expression);

			values.push(b.spread(value));
		}
	}
// ... (204 more lines)