react/packages/events/ReactGenericBatching.js

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

var ReactControlledComponent = require('./ReactControlledComponent');

// Used as a way to call batchedUpdates when we don't have a reference to
// the renderer. Such as when we're dispatching events or if third party
// libraries need to call batchedUpdates. Eventually, this API will go away when
// everything is batched by default. We'll then have a similar API to opt-out of
// scheduled work and instead do synchronous work.

// Defaults
var fiberBatchedUpdates = function(fn, bookkeeping) {
  return fn(bookkeeping);
};

function batchedUpdates(fn, bookkeeping) {
  // If we have Fiber loaded, we need to wrap this in a batching call so that
  // Fiber can apply its default priority for this call.
  return fiberBatchedUpdates(fn, bookkeeping);
}

var isNestingBatched = false;
function batchedUpdatesWithControlledComponents(fn, bookkeeping) {
  if (isNestingBatched) {
    // If we are currently inside another batch, we need to wait until it
    // fully completes before restoring state. Therefore, we add the target to
    // a queue of work.
    return batchedUpdates(fn, bookkeeping);
  }
  isNestingBatched = true;
  try {
    return batchedUpdates(fn, bookkeeping);
  } finally {
    // Here we wait until all updates have propagated, which is important
    // when using controlled components within layers:
    // https://github.com/facebook/react/issues/1698
    // Then we restore state of any controlled component.
    isNestingBatched = false;
    ReactControlledComponent.restoreStateIfNeeded();
  }
}

var ReactGenericBatchingInjection = {
  injectFiberBatchedUpdates: function(_batchedUpdates) {
    fiberBatchedUpdates = _batchedUpdates;
  },
};

var ReactGenericBatching = {
  batchedUpdates: batchedUpdatesWithControlledComponents,
  injection: ReactGenericBatchingInjection,
};

module.exports = ReactGenericBatching;