react-native/Libraries/ReactNative/UIManager.js

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict-local
 * @format
 */
'use strict';

const NativeModules = require('NativeModules');
const Platform = require('Platform');
const UIManagerProperties = require('UIManagerProperties');

const defineLazyObjectProperty = require('defineLazyObjectProperty');
const invariant = require('fbjs/lib/invariant');

const {UIManager} = NativeModules;
const viewManagerConfigs = {};

invariant(
  UIManager,
  'UIManager is undefined. The native module config is probably incorrect.',
);

// In past versions of ReactNative users called UIManager.takeSnapshot()
// However takeSnapshot was moved to ReactNative in order to support flat
// bundles and to avoid a cyclic dependency between UIManager and ReactNative.
// UIManager.takeSnapshot still exists though. In order to avoid confusion or
// accidental usage, mask the method with a deprecation warning.
UIManager.__takeSnapshot = UIManager.takeSnapshot;
UIManager.takeSnapshot = function() {
  invariant(
    false,
    'UIManager.takeSnapshot should not be called directly. ' +
      'Use ReactNative.takeSnapshot instead.',
  );
};
const triedLoadingConfig = new Set();
UIManager.getViewManagerConfig = function(viewManagerName: string) {
  if (
    viewManagerConfigs[viewManagerName] === undefined &&
    UIManager.getConstantsForViewManager
  ) {
    try {
      viewManagerConfigs[
        viewManagerName
      ] = UIManager.getConstantsForViewManager(viewManagerName);
    } catch (e) {
      viewManagerConfigs[viewManagerName] = null;
    }
  }

  const config = viewManagerConfigs[viewManagerName];
  if (config) {
    return config;
  }

  if (UIManager.lazilyLoadView && !triedLoadingConfig.has(viewManagerName)) {
    const result = UIManager.lazilyLoadView(viewManagerName);
    triedLoadingConfig.add(viewManagerName);
    if (result.viewConfig) {
      UIManager[viewManagerName] = result.viewConfig;
      lazifyViewManagerConfig(viewManagerName);
    }
  }

  return viewManagerConfigs[viewManagerName];
};

function lazifyViewManagerConfig(viewName) {
  const viewConfig = UIManager[viewName];
  if (viewConfig.Manager) {
    viewManagerConfigs[viewName] = viewConfig;
    defineLazyObjectProperty(viewConfig, 'Constants', {
      get: () => {
        const viewManager = NativeModules[viewConfig.Manager];
        const constants = {};
        viewManager &&
          Object.keys(viewManager).forEach(key => {
            const value = viewManager[key];
            if (typeof value !== 'function') {
              constants[key] = value;
            }
          });
        return constants;
      },
    });
    defineLazyObjectProperty(viewConfig, 'Commands', {
      get: () => {
        const viewManager = NativeModules[viewConfig.Manager];
        const commands = {};
        let index = 0;
        viewManager &&
          Object.keys(viewManager).forEach(key => {
            const value = viewManager[key];
            if (typeof value === 'function') {
              commands[key] = index++;
            }
          });
        return commands;
      },
    });
  }
}

/**
 * Copies the ViewManager constants and commands into UIManager. This is
 * only needed for iOS, which puts the constants in the ViewManager
 * namespace instead of UIManager, unlike Android.
 */
if (Platform.OS === 'ios') {
  Object.keys(UIManager).forEach(viewName => {
    lazifyViewManagerConfig(viewName);
  });
} else if (UIManager.ViewManagerNames) {
  // We want to add all the view managers to the UIManager.
  // However, the way things are set up, the list of view managers is not known at compile time.
  // As Prepack runs at compile it, it cannot process this loop.
  // So we wrap it in a special __residual call, which basically tells Prepack to ignore it.
  let residual = global.__residual
    ? global.__residual
    : (_, f, ...args) => f.apply(undefined, args);
  residual(
    'void',
    (UIManager, defineLazyObjectProperty) => {
      UIManager.ViewManagerNames.forEach(viewManagerName => {
        defineLazyObjectProperty(UIManager, viewManagerName, {
          get: () => UIManager.getConstantsForViewManager(viewManagerName),
        });
      });
    },
    UIManager,
    defineLazyObjectProperty,
  );

  // As Prepack now no longer knows which properties exactly the UIManager has,
  // we also tell Prepack that it has only partial knowledge of the UIManager,
  // so that any accesses to unknown properties along the global code will fail
  // when Prepack encounters them.
  if (global.__makePartial) global.__makePartial(UIManager);
}

if (__DEV__) {
  Object.keys(UIManager).forEach(viewManagerName => {
    if (!UIManagerProperties.includes(viewManagerName)) {
      if (!viewManagerConfigs[viewManagerName]) {
        viewManagerConfigs[viewManagerName] = UIManager[viewManagerName];
      }
      defineLazyObjectProperty(UIManager, viewManagerName, {
        get: () => {
          console.warn(
            `Accessing view manager configs directly off UIManager via UIManager['${viewManagerName}'] ` +
              `is no longer supported. Use UIManager.getViewManager('${viewManagerName}') instead.`,
          );
          return UIManager.getViewManagerConfig(viewManagerName);
        },
      });
    }
  });
}

module.exports = UIManager;