SvelteBoundary() — svelte Function Reference

Architecture documentation for the SvelteBoundary() function in SvelteBoundary.js from the svelte codebase.

Function javascript Compiler Transformer calls 2

Entity Profile

Compiler→ Transformer→ SvelteBoundary() — svelte Function Reference

Dependency Diagram

graph TD
  7fdec420_5da7_caf6_9113_d56e2e3c9e8e["SvelteBoundary()"]
  1831a41b_2cdc_bfcb_89c5_5a00675ed78c["SvelteBoundary.js"]
  7fdec420_5da7_caf6_9113_d56e2e3c9e8e -->|defined in| 1831a41b_2cdc_bfcb_89c5_5a00675ed78c
  9f24c33c_da34_a132_f273_3ffd2f6e5cf8["build_attribute_value()"]
  7fdec420_5da7_caf6_9113_d56e2e3c9e8e -->|calls| 9f24c33c_da34_a132_f273_3ffd2f6e5cf8
  49bc6956_1326_e1db_837c_bb4db2493060["build_template()"]
  7fdec420_5da7_caf6_9113_d56e2e3c9e8e -->|calls| 49bc6956_1326_e1db_837c_bb4db2493060
  style 7fdec420_5da7_caf6_9113_d56e2e3c9e8e fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/compiler/phases/3-transform/server/visitors/SvelteBoundary.js lines 17–71

export function SvelteBoundary(node, context) {
	// if this has a `pending` snippet, render it
	const pending_attribute = /** @type {AST.Attribute} */ (
		node.attributes.find((node) => node.type === 'Attribute' && node.name === 'pending')
	);
	const is_pending_attr_nullish =
		pending_attribute &&
		typeof pending_attribute.value === 'object' &&
		!Array.isArray(pending_attribute.value) &&
		!context.state.scope.evaluate(pending_attribute.value.expression).is_defined;

	const pending_snippet = /** @type {AST.SnippetBlock} */ (
		node.fragment.nodes.find(
			(node) => node.type === 'SnippetBlock' && node.expression.name === 'pending'
		)
	);

	if (pending_attribute || pending_snippet) {
		if (pending_attribute && is_pending_attr_nullish && !pending_snippet) {
			const callee = build_attribute_value(
				pending_attribute.value,
				context,
				(expression) => expression,
				false,
				true
			);
			const pending = b.call(callee, b.id('$$renderer'));
			const block = /** @type {BlockStatement} */ (context.visit(node.fragment));
			context.state.template.push(
				b.if(
					callee,
					b.block(build_template([block_open_else, b.stmt(pending), block_close])),
					b.block(build_template([block_open, block, block_close]))
				)
			);
		} else {
			const pending = pending_attribute
				? b.call(
						build_attribute_value(
							pending_attribute.value,
							context,
							(expression) => expression,
							false,
							true
						),
						b.id('$$renderer')
					)
				: /** @type {BlockStatement} */ (context.visit(pending_snippet.body));
			context.state.template.push(block_open_else, pending, block_close);
		}
	} else {
		const block = /** @type {BlockStatement} */ (context.visit(node.fragment));
		context.state.template.push(block_open, block, block_close);
	}
}