ReactDOMRoot.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
 */

import type {Container} from './ReactDOMHostConfig';
import type {MutableSource, ReactNodeList} from 'shared/ReactTypes';
import type {FiberRoot} from 'react-reconciler/src/ReactInternalTypes';

export type RootType = {
  render(children: ReactNodeList): void,
  unmount(): void,
  _internalRoot: FiberRoot | null,
  ...
};

export type CreateRootOptions = {
  // TODO: Remove these options.
  hydrate?: boolean,
  hydrationOptions?: {
    onHydrated?: (suspenseNode: Comment) => void,
    onDeleted?: (suspenseNode: Comment) => void,
    mutableSources?: Array<MutableSource<any>>,
    ...
  },
  // END OF TODO
  unstable_strictMode?: boolean,
  unstable_concurrentUpdatesByDefault?: boolean,
  ...
};

export type HydrateRootOptions = {
  // Hydration options
  hydratedSources?: Array<MutableSource<any>>,
  onHydrated?: (suspenseNode: Comment) => void,
  onDeleted?: (suspenseNode: Comment) => void,
  // Options for all roots
  unstable_strictMode?: boolean,
  unstable_concurrentUpdatesByDefault?: boolean,
  ...
};

import {
  isContainerMarkedAsRoot,
  markContainerAsRoot,
  unmarkContainerAsRoot,
} from './ReactDOMComponentTree';
import {listenToAllSupportedEvents} from '../events/DOMPluginEventSystem';
import {
  ELEMENT_NODE,
  COMMENT_NODE,
  DOCUMENT_NODE,
  DOCUMENT_FRAGMENT_NODE,
} from '../shared/HTMLNodeType';

import {
  createContainer,
  updateContainer,
  findHostInstanceWithNoPortals,
  registerMutableSourceForHydration,
  flushSync,
  isAlreadyRendering,
} from 'react-reconciler/src/ReactFiberReconciler';
import invariant from 'shared/invariant';
import {ConcurrentRoot} from 'react-reconciler/src/ReactRootTags';
import {allowConcurrentByDefault} from 'shared/ReactFeatureFlags';

function ReactDOMRoot(internalRoot: FiberRoot) {
  this._internalRoot = internalRoot;
}

ReactDOMRoot.prototype.render = function(children: ReactNodeList): void {
  const root = this._internalRoot;
  if (root === null) {
    invariant(false, 'Cannot update an unmounted root.');
  }

  if (__DEV__) {
    if (typeof arguments[1] === 'function') {
      console.error(
        'render(...): does not support the second callback argument. ' +
          'To execute a side effect after rendering, declare it in a component body with useEffect().',
      );
    }
    const container = root.containerInfo;

    if (container.nodeType !== COMMENT_NODE) {
      const hostInstance = findHostInstanceWithNoPortals(root.current);
      if (hostInstance) {
        if (hostInstance.parentNode !== container) {
          console.error(
            'render(...): It looks like the React-rendered content of the ' +
              'root container was removed without using React. This is not ' +
              'supported and will cause errors. Instead, call ' +
              "root.unmount() to empty a root's container.",
          );
        }
      }
    }
  }
  updateContainer(children, root, null, null);
};

ReactDOMRoot.prototype.unmount = function(): void {
  if (__DEV__) {
    if (typeof arguments[0] === 'function') {
      console.error(
        'unmount(...): does not support a callback argument. ' +
          'To execute a side effect after rendering, declare it in a component body with useEffect().',
      );
    }
  }
  const root = this._internalRoot;
  if (root !== null) {
    this._internalRoot = null;
    const container = root.containerInfo;
    if (__DEV__) {
      if (isAlreadyRendering()) {
        console.error(
          'Attempted to synchronously unmount a root while React was already ' +
            'rendering. React cannot finish unmounting the root until the ' +
            'current render has completed, which may lead to a race condition.',
        );
      }
    }
    flushSync(() => {
      updateContainer(null, root, null, null);
    });
    unmarkContainerAsRoot(container);
  }
};

export function createRoot(
  container: Container,
  options?: CreateRootOptions,
): RootType {
  invariant(
    isValidContainerLegacy(container),
    'createRoot(...): Target container is not a DOM element.',
  );
  warnIfReactDOMContainerInDEV(container);

  // TODO: Delete these options
  const hydrate = options != null && options.hydrate === true;
  const hydrationCallbacks =
    (options != null && options.hydrationOptions) || null;
  const mutableSources =
    (options != null &&
      options.hydrationOptions != null &&
      options.hydrationOptions.mutableSources) ||
    null;
  // END TODO

  const isStrictMode = options != null && options.unstable_strictMode === true;
  let concurrentUpdatesByDefaultOverride = null;
  if (allowConcurrentByDefault) {
    concurrentUpdatesByDefaultOverride =
      options != null && options.unstable_concurrentUpdatesByDefault != null
        ? options.unstable_concurrentUpdatesByDefault
        : null;
  }

  const root = createContainer(
    container,
    ConcurrentRoot,
    hydrate,
    hydrationCallbacks,
    isStrictMode,
    concurrentUpdatesByDefaultOverride,
  );
  markContainerAsRoot(root.current, container);

  const rootContainerElement =
    container.nodeType === COMMENT_NODE ? container.parentNode : container;
  listenToAllSupportedEvents(rootContainerElement);

  // TODO: Delete this path
  if (mutableSources) {
    for (let i = 0; i < mutableSources.length; i++) {
      const mutableSource = mutableSources[i];
      registerMutableSourceForHydration(root, mutableSource);
    }
  }
  // END TODO

  return new ReactDOMRoot(root);
}

export function hydrateRoot(
  container: Container,
  initialChildren: ReactNodeList,
  options?: HydrateRootOptions,
): RootType {
  invariant(
    isValidContainer(container),
    'hydrateRoot(...): Target container is not a DOM element.',
  );
  warnIfReactDOMContainerInDEV(container);

  // For now we reuse the whole bag of options since they contain
  // the hydration callbacks.
  const hydrationCallbacks = options != null ? options : null;
  const mutableSources = (options != null && options.hydratedSources) || null;
  const isStrictMode = options != null && options.unstable_strictMode === true;

  let concurrentUpdatesByDefaultOverride = null;
  if (allowConcurrentByDefault) {
    concurrentUpdatesByDefaultOverride =
      options != null && options.unstable_concurrentUpdatesByDefault != null
        ? options.unstable_concurrentUpdatesByDefault
        : null;
  }

  const root = createContainer(
    container,
    ConcurrentRoot,
    true, // hydrate
    hydrationCallbacks,
    isStrictMode,
    concurrentUpdatesByDefaultOverride,
  );
  markContainerAsRoot(root.current, container);
  // This can't be a comment node since hydration doesn't work on comment nodes anyway.
  listenToAllSupportedEvents(container);

  if (mutableSources) {
    for (let i = 0; i < mutableSources.length; i++) {
      const mutableSource = mutableSources[i];
      registerMutableSourceForHydration(root, mutableSource);
    }
  }

  // Render the initial children
  updateContainer(initialChildren, root, null, null);

  return new ReactDOMRoot(root);
}

export function isValidContainer(node: any): boolean {
  return !!(
    node &&
    (node.nodeType === ELEMENT_NODE ||
      node.nodeType === DOCUMENT_NODE ||
      node.nodeType === DOCUMENT_FRAGMENT_NODE)
  );
}

// TODO: Remove this function which also includes comment nodes.
// We only use it in places that are currently more relaxed.
export function isValidContainerLegacy(node: any): boolean {
  return !!(
    node &&
    (node.nodeType === ELEMENT_NODE ||
      node.nodeType === DOCUMENT_NODE ||
      node.nodeType === DOCUMENT_FRAGMENT_NODE ||
      (node.nodeType === COMMENT_NODE &&
        (node: any).nodeValue === ' react-mount-point-unstable '))
  );
}

function warnIfReactDOMContainerInDEV(container) {
  if (__DEV__) {
    if (
      container.nodeType === ELEMENT_NODE &&
      ((container: any): Element).tagName &&
      ((container: any): Element).tagName.toUpperCase() === 'BODY'
    ) {
      console.error(
        'createRoot(): Creating roots directly with document.body is ' +
          'discouraged, since its children are often manipulated by third-party ' +
          'scripts and browser extensions. This may lead to subtle ' +
          'reconciliation issues. Try using a container element created ' +
          'for your app.',
      );
    }
    if (isContainerMarkedAsRoot(container)) {
      if (container._reactRootContainer) {
        console.error(
          'You are calling ReactDOM.createRoot() on a container that was previously ' +
            'passed to ReactDOM.render(). This is not supported.',
        );
      } else {
        console.error(
          'You are calling ReactDOM.createRoot() on a container that ' +
            'has already been passed to createRoot() before. Instead, call ' +
            'root.render() on the existing root instead if you want to update it.',
        );
      }
    }
  }
}