pause_effects() — svelte Function Reference

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

Function javascript ClientRuntime Hydration calls 5 called by 1

Entity Profile

ClientRuntime→ Hydration→ pause_effects() — svelte Function Reference

Dependency Diagram

graph TD
  d31878b6_f94f_35ad_3c78_f4ad9319ffba["pause_effects()"]
  ca0d28d0_c4b0_db5c_32c9_bdad64d5deaa["each.js"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|defined in| ca0d28d0_c4b0_db5c_32c9_bdad64d5deaa
  3ceb9b1c_7062_d75e_744a_fd12a80dfdc9["reconcile()"]
  3ceb9b1c_7062_d75e_744a_fd12a80dfdc9 -->|calls| d31878b6_f94f_35ad_3c78_f4ad9319ffba
  27507f0c_dcab_c3a5_2ce6_5e4b1ef9df3d["pause_effect()"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|calls| 27507f0c_dcab_c3a5_2ce6_5e4b1ef9df3d
  24ab94ca_01c9_1947_75b2_801fb5cac289["destroy_effects()"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|calls| 24ab94ca_01c9_1947_75b2_801fb5cac289
  1bd7dd6f_4c22_6f44_9747_fc5ea0deaa7b["block()"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|calls| 1bd7dd6f_4c22_6f44_9747_fc5ea0deaa7b
  7bff6ec5_15bb_4289_1bd5_99cb794400ed["clear_text_content()"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|calls| 7bff6ec5_15bb_4289_1bd5_99cb794400ed
  a199a3f7_5497_5329_2c7c_fc4555548da6["clear()"]
  d31878b6_f94f_35ad_3c78_f4ad9319ffba -->|calls| a199a3f7_5497_5329_2c7c_fc4555548da6
  style d31878b6_f94f_35ad_3c78_f4ad9319ffba fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/internal/client/dom/blocks/each.js lines 64–126

function pause_effects(state, to_destroy, controlled_anchor) {
	/** @type {TransitionManager[]} */
	var transitions = [];
	var length = to_destroy.length;

	/** @type {EachOutroGroup} */
	var group;
	var remaining = to_destroy.length;

	for (var i = 0; i < length; i++) {
		let effect = to_destroy[i];

		pause_effect(
			effect,
			() => {
				if (group) {
					group.pending.delete(effect);
					group.done.add(effect);

					if (group.pending.size === 0) {
						var groups = /** @type {Set<EachOutroGroup>} */ (state.outrogroups);

						destroy_effects(array_from(group.done));
						groups.delete(group);

						if (groups.size === 0) {
							state.outrogroups = null;
						}
					}
				} else {
					remaining -= 1;
				}
			},
			false
		);
	}

	if (remaining === 0) {
		// If we're in a controlled each block (i.e. the block is the only child of an
		// element), and we are removing all items, _and_ there are no out transitions,
		// we can use the fast path — emptying the element and replacing the anchor
		var fast_path = transitions.length === 0 && controlled_anchor !== null;

		if (fast_path) {
			var anchor = /** @type {Element} */ (controlled_anchor);
			var parent_node = /** @type {Element} */ (anchor.parentNode);

			clear_text_content(parent_node);
			parent_node.append(anchor);

			state.items.clear();
		}

		destroy_effects(to_destroy, !fast_path);
	} else {
		group = {
			pending: new Set(to_destroy),
			done: new Set()
		};

		(state.outrogroups ??= new Set()).add(group);
	}
}