ReactNativeAttributePayload.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

// Modules provided by RN:
import {
  deepDiffer,
  flattenStyle,
} from 'react-native/Libraries/ReactPrivate/ReactNativePrivateInterface';
import isArray from 'shared/isArray';

import type {AttributeConfiguration} from './ReactNativeTypes';

const emptyObject = {};

/**
 * Create a payload that contains all the updates between two sets of props.
 *
 * These helpers are all encapsulated into a single module, because they use
 * mutation as a performance optimization which leads to subtle shared
 * dependencies between the code paths. To avoid this mutable state leaking
 * across modules, I've kept them isolated to this module.
 */

type NestedNode = Array<NestedNode> | Object;

// Tracks removed keys
let removedKeys: {[string]: boolean} | null = null;
let removedKeyCount = 0;

const deepDifferOptions = {
  unsafelyIgnoreFunctions: true,
};

function defaultDiffer(prevProp: mixed, nextProp: mixed): boolean {
  if (typeof nextProp !== 'object' || nextProp === null) {
    // Scalars have already been checked for equality
    return true;
  } else {
    // For objects and arrays, the default diffing algorithm is a deep compare
    return deepDiffer(prevProp, nextProp, deepDifferOptions);
  }
}

function restoreDeletedValuesInNestedArray(
  updatePayload: Object,
  node: NestedNode,
  validAttributes: AttributeConfiguration,
) {
  if (isArray(node)) {
    let i = node.length;
    while (i-- && removedKeyCount > 0) {
      restoreDeletedValuesInNestedArray(
        updatePayload,
        node[i],
// ... (433 more lines)