TransitionDirective.js — svelte Source File

Source Code

/** @import { Expression } from 'estree' */
/** @import { AST } from '#compiler' */
/** @import { ComponentContext } from '../types' */
import { TRANSITION_GLOBAL, TRANSITION_IN, TRANSITION_OUT } from '../../../../../constants.js';
import * as b from '#compiler/builders';
import { parse_directive_name } from './shared/utils.js';

/**
 * @param {AST.TransitionDirective} node
 * @param {ComponentContext} context
 */
export function TransitionDirective(node, context) {
	let flags = node.modifiers.includes('global') ? TRANSITION_GLOBAL : 0;
	if (node.intro) flags |= TRANSITION_IN;
	if (node.outro) flags |= TRANSITION_OUT;

	const args = [
		b.literal(flags),
		context.state.node,
		b.thunk(/** @type {Expression} */ (context.visit(parse_directive_name(node.name))))
	];

	if (node.expression) {
		args.push(b.thunk(/** @type {Expression} */ (context.visit(node.expression))));
	}

	// in after_update to ensure it always happens after bind:this
	let statement = b.stmt(b.call('$.transition', ...args));

	if (node.metadata.expression.is_async()) {
		statement = b.stmt(
			b.call(
				'$.run_after_blockers',
				node.metadata.expression.blockers(),
				b.thunk(b.block([statement]))
			)
		);
	}

	context.state.after_update.push(statement);
}