process() — svelte Function Reference

Source Code

packages/svelte/src/internal/client/reactivity/batch.js lines 185–235

	process(root_effects) {
		queued_root_effects = [];

		this.apply();

		/** @type {Effect[]} */
		var effects = [];

		/** @type {Effect[]} */
		var render_effects = [];

		for (const root of root_effects) {
			this.#traverse_effect_tree(root, effects, render_effects);
			// Note: #traverse_effect_tree runs block effects eagerly, which can schedule effects,
			// which means queued_root_effects now may be filled again.

			// Helpful for debugging reactivity loss that has to do with branches being skipped:
			// log_inconsistent_branches(root);
		}

		if (this.is_deferred()) {
			this.#defer_effects(render_effects);
			this.#defer_effects(effects);

			for (const [e, t] of this.#skipped_branches) {
				reset_branch(e, t);
			}
		} else {
			// append/remove branches
			for (const fn of this.#commit_callbacks) fn();
			this.#commit_callbacks.clear();

			if (this.#pending === 0) {
				this.#commit();
			}

			// If sources are written to, then work needs to happen in a separate batch, else prior sources would be mixed with
			// newly updated sources, which could lead to infinite loops when effects run over and over again.
			previous_batch = this;
			current_batch = null;

			flush_queued_effects(render_effects);
			flush_queued_effects(effects);

			previous_batch = null;

			this.#deferred?.resolve();
		}

		batch_values = null;
	}