react-dom/lib/ReactCompositeComponent.js

/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 */

'use strict';

var _prodInvariant = require('./reactProdInvariant'),
    _assign = require('object-assign');

var React = require('react/lib/React');
var ReactComponentEnvironment = require('./ReactComponentEnvironment');
var ReactCurrentOwner = require('react/lib/ReactCurrentOwner');
var ReactErrorUtils = require('./ReactErrorUtils');
var ReactInstanceMap = require('./ReactInstanceMap');
var ReactInstrumentation = require('./ReactInstrumentation');
var ReactNodeTypes = require('./ReactNodeTypes');
var ReactReconciler = require('./ReactReconciler');

if (process.env.NODE_ENV !== 'production') {
  var checkReactTypeSpec = require('./checkReactTypeSpec');
}

var emptyObject = require('fbjs/lib/emptyObject');
var invariant = require('fbjs/lib/invariant');
var shallowEqual = require('fbjs/lib/shallowEqual');
var shouldUpdateReactComponent = require('./shouldUpdateReactComponent');
var warning = require('fbjs/lib/warning');

var CompositeTypes = {
  ImpureClass: 0,
  PureClass: 1,
  StatelessFunctional: 2
};

function StatelessComponent(Component) {}
StatelessComponent.prototype.render = function () {
  var Component = ReactInstanceMap.get(this)._currentElement.type;
  var element = Component(this.props, this.context, this.updater);
  warnIfInvalidElement(Component, element);
  return element;
};

function warnIfInvalidElement(Component, element) {
  if (process.env.NODE_ENV !== 'production') {
    process.env.NODE_ENV !== 'production' ? warning(element === null || element === false || React.isValidElement(element), '%s(...): A valid React element (or null) must be returned. You may have ' + 'returned undefined, an array or some other invalid object.', Component.displayName || Component.name || 'Component') : void 0;
    process.env.NODE_ENV !== 'production' ? warning(!Component.childContextTypes, '%s(...): childContextTypes cannot be defined on a functional component.', Component.displayName || Component.name || 'Component') : void 0;
  }
}

function shouldConstruct(Component) {
  return !!(Component.prototype && Component.prototype.isReactComponent);
}

function isPureComponent(Component) {
  return !!(Component.prototype && Component.prototype.isPureReactComponent);
}

// Separated into a function to contain deoptimizations caused by try/finally.
function measureLifeCyclePerf(fn, debugID, timerType) {
  if (debugID === 0) {
    // Top-level wrappers (see ReactMount) and empty components (see
    // ReactDOMEmptyComponent) are invisible to hooks and devtools.
    // Both are implementation details that should go away in the future.
    return fn();
  }

  ReactInstrumentation.debugTool.onBeginLifeCycleTimer(debugID, timerType);
  try {
    return fn();
  } finally {
    ReactInstrumentation.debugTool.onEndLifeCycleTimer(debugID, timerType);
  }
}

/**
 * ------------------ The Life-Cycle of a Composite Component ------------------
 *
 * - constructor: Initialization of state. The instance is now retained.
 *   - componentWillMount
 *   - render
 *   - [children's constructors]
 *     - [children's componentWillMount and render]
 *     - [children's componentDidMount]
 *     - componentDidMount
 *
 *       Update Phases:
 *       - componentWillReceiveProps (only called if parent updated)
 *       - shouldComponentUpdate
 *         - componentWillUpdate
 *           - render
 *           - [children's constructors or receive props phases]
 *         - componentDidUpdate
 *
 *     - componentWillUnmount
 *     - [children's componentWillUnmount]
 *   - [children destroyed]
 * - (destroyed): The instance is now blank, released by React and ready for GC.
 *
 * -----------------------------------------------------------------------------
 */

/**
 * An incrementing ID assigned to each component when it is mounted. This is
 * used to enforce the order in which `ReactUpdates` updates dirty components.
 *
 * @private
 */
var nextMountID = 1;

/**
 * @lends {ReactCompositeComponent.prototype}
 */
var ReactCompositeComponent = {
  /**
   * Base constructor for all composite component.
   *
   * @param {ReactElement} element
   * @final
   * @internal
   */
  construct: function (element) {
    this._currentElement = element;
    this._rootNodeID = 0;
    this._compositeType = null;
    this._instance = null;
    this._hostParent = null;
    this._hostContainerInfo = null;

    // See ReactUpdateQueue
    this._updateBatchNumber = null;
    this._pendingElement = null;
    this._pendingStateQueue = null;
    this._pendingReplaceState = false;
    this._pendingForceUpdate = false;

    this._renderedNodeType = null;
    this._renderedComponent = null;
    this._context = null;
    this._mountOrder = 0;
    this._topLevelWrapper = null;

    // See ReactUpdates and ReactUpdateQueue.
    this._pendingCallbacks = null;

    // ComponentWillUnmount shall only be called once
    this._calledComponentWillUnmount = false;

    if (process.env.NODE_ENV !== 'production') {
      this._warnedAboutRefsInRender = false;
    }
  },

  /**
   * Initializes the component, renders markup, and registers event listeners.
   *
   * @param {ReactReconcileTransaction|ReactServerRenderingTransaction} transaction
   * @param {?object} hostParent
   * @param {?object} hostContainerInfo
   * @param {?object} context
   * @return {?string} Rendered markup to be inserted into the DOM.
   * @final
   * @internal
   */
  mountComponent: function (transaction, hostParent, hostContainerInfo, context) {
    var _this = this;

    this._context = context;
    this._mountOrder = nextMountID++;
    this._hostParent = hostParent;
    this._hostContainerInfo = hostContainerInfo;

    var publicProps = this._currentElement.props;
    var publicContext = this._processContext(context);

    var Component = this._currentElement.type;

    var updateQueue = transaction.getUpdateQueue();

    // Initialize the public class
    var doConstruct = shouldConstruct(Component);
    var inst = this._constructComponent(doConstruct, publicProps, publicContext, updateQueue);
    var renderedElement;

    // Support functional components
    if (!doConstruct && (inst == null || inst.render == null)) {
      renderedElement = inst;
      warnIfInvalidElement(Component, renderedElement);
      !(inst === null || inst === false || React.isValidElement(inst)) ? process.env.NODE_ENV !== 'production' ? invariant(false, '%s(...): A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.', Component.displayName || Component.name || 'Component') : _prodInvariant('105', Component.displayName || Component.name || 'Component') : void 0;
      inst = new StatelessComponent(Component);
      this._compositeType = CompositeTypes.StatelessFunctional;
    } else {
      if (isPureComponent(Component)) {
        this._compositeType = CompositeTypes.PureClass;
      } else {
        this._compositeType = CompositeTypes.ImpureClass;
      }
    }

    if (process.env.NODE_ENV !== 'production') {
      // This will throw later in _renderValidatedComponent, but add an early
      // warning now to help debugging
      if (inst.render == null) {
        process.env.NODE_ENV !== 'production' ? warning(false, '%s(...): No `render` method found on the returned component ' + 'instance: you may have forgotten to define `render`.', Component.displayName || Component.name || 'Component') : void 0;
      }

      var propsMutated = inst.props !== publicProps;
      var componentName = Component.displayName || Component.name || 'Component';

      process.env.NODE_ENV !== 'production' ? warning(inst.props === undefined || !propsMutated, '%s(...): When calling super() in `%s`, make sure to pass ' + "up the same props that your component's constructor was passed.", componentName, componentName) : void 0;
    }

    // These should be set up in the constructor, but as a convenience for
    // simpler class abstractions, we set them up after the fact.
    inst.props = publicProps;
    inst.context = publicContext;
    inst.refs = emptyObject;
    inst.updater = updateQueue;

    this._instance = inst;

    // Store a reference from the instance back to the internal representation
    ReactInstanceMap.set(inst, this);

    if (process.env.NODE_ENV !== 'production') {
      // Since plain JS classes are defined without any special initialization
      // logic, we can not catch common errors early. Therefore, we have to
      // catch them here, at initialization time, instead.
      process.env.NODE_ENV !== 'production' ? warning(!inst.getInitialState || inst.getInitialState.isReactClassApproved || inst.state, 'getInitialState was defined on %s, a plain JavaScript class. ' + 'This is only supported for classes created using React.createClass. ' + 'Did you mean to define a state property instead?', this.getName() || 'a component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(!inst.getDefaultProps || inst.getDefaultProps.isReactClassApproved, 'getDefaultProps was defined on %s, a plain JavaScript class. ' + 'This is only supported for classes created using React.createClass. ' + 'Use a static property to define defaultProps instead.', this.getName() || 'a component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(!inst.propTypes, 'propTypes was defined as an instance property on %s. Use a static ' + 'property to define propTypes instead.', this.getName() || 'a component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(!inst.contextTypes, 'contextTypes was defined as an instance property on %s. Use a ' + 'static property to define contextTypes instead.', this.getName() || 'a component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(typeof inst.componentShouldUpdate !== 'function', '%s has a method called ' + 'componentShouldUpdate(). Did you mean shouldComponentUpdate()? ' + 'The name is phrased as a question because the function is ' + 'expected to return a value.', this.getName() || 'A component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(typeof inst.componentDidUnmount !== 'function', '%s has a method called ' + 'componentDidUnmount(). But there is no such lifecycle method. ' + 'Did you mean componentWillUnmount()?', this.getName() || 'A component') : void 0;
      process.env.NODE_ENV !== 'production' ? warning(typeof inst.componentWillRecieveProps !== 'function', '%s has a method called ' + 'componentWillRecieveProps(). Did you mean componentWillReceiveProps()?', this.getName() || 'A component') : void 0;
    }

    var initialState = inst.state;
    if (initialState === undefined) {
      inst.state = initialState = null;
    }
    !(typeof initialState === 'object' && !Array.isArray(initialState)) ? process.env.NODE_ENV !== 'production' ? invariant(false, '%s.state: must be set to an object or null', this.getName() || 'ReactCompositeComponent') : _prodInvariant('106', this.getName() || 'ReactCompositeComponent') : void 0;

    this._pendingStateQueue = null;
    this._pendingReplaceState = false;
    this._pendingForceUpdate = false;

    var markup;
    if (inst.unstable_handleError) {
      markup = this.performInitialMountWithErrorHandling(renderedElement, hostParent, hostContainerInfo, transaction, context);
    } else {
      markup = this.performInitialMount(renderedElement, hostParent, hostContainerInfo, transaction, context);
    }

    if (inst.componentDidMount) {
      if (process.env.NODE_ENV !== 'production') {
        transaction.getReactMountReady().enqueue(function () {
          measureLifeCyclePerf(function () {
            return inst.componentDidMount();
          }, _this._debugID, 'componentDidMount');
        });
      } else {
        transaction.getReactMountReady().enqueue(inst.componentDidMount, inst);
      }
    }

    return markup;
  },

  _constructComponent: function (doConstruct, publicProps, publicContext, updateQueue) {
    if (process.env.NODE_ENV !== 'production') {
      ReactCurrentOwner.current = this;
      try {
        return this._constructComponentWithoutOwner(doConstruct, publicProps, publicContext, updateQueue);
      } finally {
        ReactCurrentOwner.current = null;
      }
    } else {
      return this._constructComponentWithoutOwner(doConstruct, publicProps, publicContext, updateQueue);
    }
  },

  _constructComponentWithoutOwner: function (doConstruct, publicProps, publicContext, updateQueue) {
    var Component = this._currentElement.type;

    if (doConstruct) {
      if (process.env.NODE_ENV !== 'production') {
        return measureLifeCyclePerf(function () {
          return new Component(publicProps, publicContext, updateQueue);
        }, this._debugID, 'ctor');
      } else {
        return new Component(publicProps, publicContext, updateQueue);
      }
    }

    // This can still be an instance in case of factory components
    // but we'll count this as time spent rendering as the more common case.
    if (process.env.NODE_ENV !== 'production') {
      return measureLifeCyclePerf(function () {
        return Component(publicProps, publicContext, updateQueue);
      }, this._debugID, 'render');
    } else {
      return Component(publicProps, publicContext, updateQueue);
    }
  },

  performInitialMountWithErrorHandling: function (renderedElement, hostParent, hostContainerInfo, transaction, context) {
    var markup;
    var checkpoint = transaction.checkpoint();
    try {
      markup = this.performInitialMount(renderedElement, hostParent, hostContainerInfo, transaction, context);
    } catch (e) {
      // Roll back to checkpoint, handle error (which may add items to the transaction), and take a new checkpoint
      transaction.rollback(checkpoint);
      this._instance.unstable_handleError(e);
      if (this._pendingStateQueue) {
        this._instance.state = this._processPendingState(this._instance.props, this._instance.context);
      }
      checkpoint = transaction.checkpoint();

      this._renderedComponent.unmountComponent(true);
      transaction.rollback(checkpoint);

      // Try again - we've informed the component about the error, so they can render an error message this time.
      // If this throws again, the error will bubble up (and can be caught by a higher error boundary).
      markup = this.performInitialMount(renderedElement, hostParent, hostContainerInfo, transaction, context);
    }
    return markup;
  },

  performInitialMount: function (renderedElement, hostParent, hostContainerInfo, transaction, context) {
    var inst = this._instance;

    var debugID = 0;
    if (process.env.NODE_ENV !== 'production') {
      debugID = this._debugID;
    }

    if (inst.componentWillMount) {
      if (process.env.NODE_ENV !== 'production') {
        measureLifeCyclePerf(function () {
          return inst.componentWillMount();
        }, debugID, 'componentWillMount');
      } else {
        inst.componentWillMount();
      }
      // When mounting, calls to `setState` by `componentWillMount` will set
      // `this._pendingStateQueue` without triggering a re-render.
      if (this._pendingStateQueue) {
        inst.state = this._processPendingState(inst.props, inst.context);
      }
    }

    // If not a stateless component, we now render
    if (renderedElement === undefined) {
      renderedElement = this._renderValidatedComponent();
    }

    var nodeType = ReactNodeTypes.getType(renderedElement);
    this._renderedNodeType = nodeType;
    var child = this._instantiateReactComponent(renderedElement, nodeType !== ReactNodeTypes.EMPTY /* shouldHaveDebugID */
    );
    this._renderedComponent = child;

    var markup = ReactReconciler.mountComponent(child, transaction, hostParent, hostContainerInfo, this._processChildContext(context), debugID);

    if (process.env.NODE_ENV !== 'production') {
      if (debugID !== 0) {
        var childDebugIDs = child._debugID !== 0 ? [child._debugID] : [];
        ReactInstrumentation.debugTool.onSetChildren(debugID, childDebugIDs);
      }
    }

    return markup;
  },

  getHostNode: function () {
    return ReactReconciler.getHostNode(this._renderedComponent);
  },

  /**
   * Releases any resources allocated by `mountComponent`.
   *
   * @final
   * @internal
   */
  unmountComponent: function (safely) {
    if (!this._renderedComponent) {
      return;
    }

    var inst = this._instance;

    if (inst.componentWillUnmount && !inst._calledComponentWillUnmount) {
      inst._calledComponentWillUnmount = true;

      if (safely) {
        var name = this.getName() + '.componentWillUnmount()';
        ReactErrorUtils.invokeGuardedCallback(name, inst.componentWillUnmount.bind(inst));
      } else {
        if (process.env.NODE_ENV !== 'production') {
          measureLifeCyclePerf(function () {
            return inst.componentWillUnmount();
          }, this._debugID, 'componentWillUnmount');
        } else {
          inst.componentWillUnmount();
        }
      }
    }

    if (this._renderedComponent) {
      ReactReconciler.unmountComponent(this._renderedComponent, safely);
      this._renderedNodeType = null;
      this._renderedComponent = null;
      this._instance = null;
    }

    // Reset pending fields
    // Even if this component is scheduled for another update in ReactUpdates,
    // it would still be ignored because these fields are reset.
    this._pendingStateQueue = null;
    this._pendingReplaceState = false;
    this._pendingForceUpdate = false;
    this._pendingCallbacks = null;
    this._pendingElement = null;

    // These fields do not really need to be reset since this object is no
    // longer accessible.
    this._context = null;
    this._rootNodeID = 0;
    this._topLevelWrapper = null;

    // Delete the reference from the instance to this internal representation
    // which allow the internals to be properly cleaned up even if the user
    // leaks a reference to the public instance.
    ReactInstanceMap.remove(inst);

    // Some existing components rely on inst.props even after they've been
    // destroyed (in event handlers).
    // TODO: inst.props = null;
    // TODO: inst.state = null;
    // TODO: inst.context = null;
  },

  /**
   * Filters the context object to only contain keys specified in
   * `contextTypes`
   *
   * @param {object} context
   * @return {?object}
   * @private
   */
  _maskContext: function (context) {
    var Component = this._currentElement.type;
    var contextTypes = Component.contextTypes;
    if (!contextTypes) {
      return emptyObject;
    }
    var maskedContext = {};
    for (var contextName in contextTypes) {
      maskedContext[contextName] = context[contextName];
    }
    return maskedContext;
  },

  /**
   * Filters the context object to only contain keys specified in
   * `contextTypes`, and asserts that they are valid.
   *
   * @param {object} context
   * @return {?object}
   * @private
   */
  _processContext: function (context) {
    var maskedContext = this._maskContext(context);
    if (process.env.NODE_ENV !== 'production') {
      var Component = this._currentElement.type;
      if (Component.contextTypes) {
        this._checkContextTypes(Component.contextTypes, maskedContext, 'context');
      }
    }
    return maskedContext;
  },

  /**
   * @param {object} currentContext
   * @return {object}
   * @private
   */
  _processChildContext: function (currentContext) {
    var Component = this._currentElement.type;
    var inst = this._instance;
    var childContext;

    if (inst.getChildContext) {
      if (process.env.NODE_ENV !== 'production') {
        ReactInstrumentation.debugTool.onBeginProcessingChildContext();
        try {
          childContext = inst.getChildContext();
        } finally {
          ReactInstrumentation.debugTool.onEndProcessingChildContext();
        }
      } else {
        childContext = inst.getChildContext();
      }
    }

    if (childContext) {
      !(typeof Component.childContextTypes === 'object') ? process.env.NODE_ENV !== 'production' ? invariant(false, '%s.getChildContext(): childContextTypes must be defined in order to use getChildContext().', this.getName() || 'ReactCompositeComponent') : _prodInvariant('107', this.getName() || 'ReactCompositeComponent') : void 0;
      if (process.env.NODE_ENV !== 'production') {
        this._checkContextTypes(Component.childContextTypes, childContext, 'child context');
      }
      for (var name in childContext) {
        !(name in Component.childContextTypes) ? process.env.NODE_ENV !== 'production' ? invariant(false, '%s.getChildContext(): key "%s" is not defined in childContextTypes.', this.getName() || 'ReactCompositeComponent', name) : _prodInvariant('108', this.getName() || 'ReactCompositeComponent', name) : void 0;
      }
      return _assign({}, currentContext, childContext);
    }
    return currentContext;
  },

  /**
   * Assert that the context types are valid
   *
   * @param {object} typeSpecs Map of context field to a ReactPropType
   * @param {object} values Runtime values that need to be type-checked
   * @param {string} location e.g. "prop", "context", "child context"
   * @private
   */
  _checkContextTypes: function (typeSpecs, values, location) {
    if (process.env.NODE_ENV !== 'production') {
      checkReactTypeSpec(typeSpecs, values, location, this.getName(), null, this._debugID);
    }
  },

  receiveComponent: function (nextElement, transaction, nextContext) {
    var prevElement = this._currentElement;
    var prevContext = this._context;

    this._pendingElement = null;

    this.updateComponent(transaction, prevElement, nextElement, prevContext, nextContext);
  },

  /**
   * If any of `_pendingElement`, `_pendingStateQueue`, or `_pendingForceUpdate`
   * is set, update the component.
   *
   * @param {ReactReconcileTransaction} transaction
   * @internal
   */
  performUpdateIfNecessary: function (transaction) {
    if (this._pendingElement != null) {
      ReactReconciler.receiveComponent(this, this._pendingElement, transaction, this._context);
    } else if (this._pendingStateQueue !== null || this._pendingForceUpdate) {
      this.updateComponent(transaction, this._currentElement, this._currentElement, this._context, this._context);
    } else {
      this._updateBatchNumber = null;
    }
  },

  /**
   * Perform an update to a mounted component. The componentWillReceiveProps and
   * shouldComponentUpdate methods are called, then (assuming the update isn't
   * skipped) the remaining update lifecycle methods are called and the DOM
   * representation is updated.
   *
   * By default, this implements React's rendering and reconciliation algorithm.
   * Sophisticated clients may wish to override this.
   *
   * @param {ReactReconcileTransaction} transaction
   * @param {ReactElement} prevParentElement
   * @param {ReactElement} nextParentElement
   * @internal
   * @overridable
   */
  updateComponent: function (transaction, prevParentElement, nextParentElement, prevUnmaskedContext, nextUnmaskedContext) {
    var inst = this._instance;
    !(inst != null) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'Attempted to update component `%s` that has already been unmounted (or failed to mount).', this.getName() || 'ReactCompositeComponent') : _prodInvariant('136', this.getName() || 'ReactCompositeComponent') : void 0;

    var willReceive = false;
    var nextContext;

    // Determine if the context has changed or not
    if (this._context === nextUnmaskedContext) {
      nextContext = inst.context;
    } else {
      nextContext = this._processContext(nextUnmaskedContext);
      willReceive = true;
    }

    var prevProps = prevParentElement.props;
    var nextProps = nextParentElement.props;

    // Not a simple state update but a props update
    if (prevParentElement !== nextParentElement) {
      willReceive = true;
    }

    // An update here will schedule an update but immediately set
    // _pendingStateQueue which will ensure that any state updates gets
    // immediately reconciled instead of waiting for the next batch.
    if (willReceive && inst.componentWillReceiveProps) {
      if (process.env.NODE_ENV !== 'production') {
        measureLifeCyclePerf(function () {
          return inst.componentWillReceiveProps(nextProps, nextContext);
        }, this._debugID, 'componentWillReceiveProps');
      } else {
        inst.componentWillReceiveProps(nextProps, nextContext);
      }
    }

    var nextState = this._processPendingState(nextProps, nextContext);
    var shouldUpdate = true;

    if (!this._pendingForceUpdate) {
      if (inst.shouldComponentUpdate) {
        if (process.env.NODE_ENV !== 'production') {
          shouldUpdate = measureLifeCyclePerf(function () {
            return inst.shouldComponentUpdate(nextProps, nextState, nextContext);
          }, this._debugID, 'shouldComponentUpdate');
        } else {
          shouldUpdate = inst.shouldComponentUpdate(nextProps, nextState, nextContext);
        }
      } else {
        if (this._compositeType === CompositeTypes.PureClass) {
          shouldUpdate = !shallowEqual(prevProps, nextProps) || !shallowEqual(inst.state, nextState);
        }
      }
    }

    if (process.env.NODE_ENV !== 'production') {
      process.env.NODE_ENV !== 'production' ? warning(shouldUpdate !== undefined, '%s.shouldComponentUpdate(): Returned undefined instead of a ' + 'boolean value. Make sure to return true or false.', this.getName() || 'ReactCompositeComponent') : void 0;
    }

    this._updateBatchNumber = null;
    if (shouldUpdate) {
      this._pendingForceUpdate = false;
      // Will set `this.props`, `this.state` and `this.context`.
      this._performComponentUpdate(nextParentElement, nextProps, nextState, nextContext, transaction, nextUnmaskedContext);
    } else {
      // If it's determined that a component should not update, we still want
      // to set props and state but we shortcut the rest of the update.
      this._currentElement = nextParentElement;
      this._context = nextUnmaskedContext;
      inst.props = nextProps;
      inst.state = nextState;
      inst.context = nextContext;
    }
  },

  _processPendingState: function (props, context) {
    var inst = this._instance;
    var queue = this._pendingStateQueue;
    var replace = this._pendingReplaceState;
    this._pendingReplaceState = false;
    this._pendingStateQueue = null;

    if (!queue) {
      return inst.state;
    }

    if (replace && queue.length === 1) {
      return queue[0];
    }

    var nextState = _assign({}, replace ? queue[0] : inst.state);
    for (var i = replace ? 1 : 0; i < queue.length; i++) {
      var partial = queue[i];
      _assign(nextState, typeof partial === 'function' ? partial.call(inst, nextState, props, context) : partial);
    }

    return nextState;
  },

  /**
   * Merges new props and state, notifies delegate methods of update and
   * performs update.
   *
   * @param {ReactElement} nextElement Next element
   * @param {object} nextProps Next public object to set as properties.
   * @param {?object} nextState Next object to set as state.
   * @param {?object} nextContext Next public object to set as context.
   * @param {ReactReconcileTransaction} transaction
   * @param {?object} unmaskedContext
   * @private
   */
  _performComponentUpdate: function (nextElement, nextProps, nextState, nextContext, transaction, unmaskedContext) {
    var _this2 = this;

    var inst = this._instance;

    var hasComponentDidUpdate = Boolean(inst.componentDidUpdate);
    var prevProps;
    var prevState;
    var prevContext;
    if (hasComponentDidUpdate) {
      prevProps = inst.props;
      prevState = inst.state;
      prevContext = inst.context;
    }

    if (inst.componentWillUpdate) {
      if (process.env.NODE_ENV !== 'production') {
        measureLifeCyclePerf(function () {
          return inst.componentWillUpdate(nextProps, nextState, nextContext);
        }, this._debugID, 'componentWillUpdate');
      } else {
        inst.componentWillUpdate(nextProps, nextState, nextContext);
      }
    }

    this._currentElement = nextElement;
    this._context = unmaskedContext;
    inst.props = nextProps;
    inst.state = nextState;
    inst.context = nextContext;

    this._updateRenderedComponent(transaction, unmaskedContext);

    if (hasComponentDidUpdate) {
      if (process.env.NODE_ENV !== 'production') {
        transaction.getReactMountReady().enqueue(function () {
          measureLifeCyclePerf(inst.componentDidUpdate.bind(inst, prevProps, prevState, prevContext), _this2._debugID, 'componentDidUpdate');
        });
      } else {
        transaction.getReactMountReady().enqueue(inst.componentDidUpdate.bind(inst, prevProps, prevState, prevContext), inst);
      }
    }
  },

  /**
   * Call the component's `render` method and update the DOM accordingly.
   *
   * @param {ReactReconcileTransaction} transaction
   * @internal
   */
  _updateRenderedComponent: function (transaction, context) {
    var prevComponentInstance = this._renderedComponent;
    var prevRenderedElement = prevComponentInstance._currentElement;
    var nextRenderedElement = this._renderValidatedComponent();

    var debugID = 0;
    if (process.env.NODE_ENV !== 'production') {
      debugID = this._debugID;
    }

    if (shouldUpdateReactComponent(prevRenderedElement, nextRenderedElement)) {
      ReactReconciler.receiveComponent(prevComponentInstance, nextRenderedElement, transaction, this._processChildContext(context));
    } else {
      var oldHostNode = ReactReconciler.getHostNode(prevComponentInstance);
      ReactReconciler.unmountComponent(prevComponentInstance, false);

      var nodeType = ReactNodeTypes.getType(nextRenderedElement);
      this._renderedNodeType = nodeType;
      var child = this._instantiateReactComponent(nextRenderedElement, nodeType !== ReactNodeTypes.EMPTY /* shouldHaveDebugID */
      );
      this._renderedComponent = child;

      var nextMarkup = ReactReconciler.mountComponent(child, transaction, this._hostParent, this._hostContainerInfo, this._processChildContext(context), debugID);

      if (process.env.NODE_ENV !== 'production') {
        if (debugID !== 0) {
          var childDebugIDs = child._debugID !== 0 ? [child._debugID] : [];
          ReactInstrumentation.debugTool.onSetChildren(debugID, childDebugIDs);
        }
      }

      this._replaceNodeWithMarkup(oldHostNode, nextMarkup, prevComponentInstance);
    }
  },

  /**
   * Overridden in shallow rendering.
   *
   * @protected
   */
  _replaceNodeWithMarkup: function (oldHostNode, nextMarkup, prevInstance) {
    ReactComponentEnvironment.replaceNodeWithMarkup(oldHostNode, nextMarkup, prevInstance);
  },

  /**
   * @protected
   */
  _renderValidatedComponentWithoutOwnerOrContext: function () {
    var inst = this._instance;
    var renderedElement;

    if (process.env.NODE_ENV !== 'production') {
      renderedElement = measureLifeCyclePerf(function () {
        return inst.render();
      }, this._debugID, 'render');
    } else {
      renderedElement = inst.render();
    }

    if (process.env.NODE_ENV !== 'production') {
      // We allow auto-mocks to proceed as if they're returning null.
      if (renderedElement === undefined && inst.render._isMockFunction) {
        // This is probably bad practice. Consider warning here and
        // deprecating this convenience.
        renderedElement = null;
      }
    }

    return renderedElement;
  },

  /**
   * @private
   */
  _renderValidatedComponent: function () {
    var renderedElement;
    if (process.env.NODE_ENV !== 'production' || this._compositeType !== CompositeTypes.StatelessFunctional) {
      ReactCurrentOwner.current = this;
      try {
        renderedElement = this._renderValidatedComponentWithoutOwnerOrContext();
      } finally {
        ReactCurrentOwner.current = null;
      }
    } else {
      renderedElement = this._renderValidatedComponentWithoutOwnerOrContext();
    }
    !(
    // TODO: An `isValidNode` function would probably be more appropriate
    renderedElement === null || renderedElement === false || React.isValidElement(renderedElement)) ? process.env.NODE_ENV !== 'production' ? invariant(false, '%s.render(): A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.', this.getName() || 'ReactCompositeComponent') : _prodInvariant('109', this.getName() || 'ReactCompositeComponent') : void 0;

    return renderedElement;
  },

  /**
   * Lazily allocates the refs object and stores `component` as `ref`.
   *
   * @param {string} ref Reference name.
   * @param {component} component Component to store as `ref`.
   * @final
   * @private
   */
  attachRef: function (ref, component) {
    var inst = this.getPublicInstance();
    !(inst != null) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'Stateless function components cannot have refs.') : _prodInvariant('110') : void 0;
    var publicComponentInstance = component.getPublicInstance();
    if (process.env.NODE_ENV !== 'production') {
      var componentName = component && component.getName ? component.getName() : 'a component';
      process.env.NODE_ENV !== 'production' ? warning(publicComponentInstance != null || component._compositeType !== CompositeTypes.StatelessFunctional, 'Stateless function components cannot be given refs ' + '(See ref "%s" in %s created by %s). ' + 'Attempts to access this ref will fail.', ref, componentName, this.getName()) : void 0;
    }
    var refs = inst.refs === emptyObject ? inst.refs = {} : inst.refs;
    refs[ref] = publicComponentInstance;
  },

  /**
   * Detaches a reference name.
   *
   * @param {string} ref Name to dereference.
   * @final
   * @private
   */
  detachRef: function (ref) {
    var refs = this.getPublicInstance().refs;
    delete refs[ref];
  },

  /**
   * Get a text description of the component that can be used to identify it
   * in error messages.
   * @return {string} The name or null.
   * @internal
   */
  getName: function () {
    var type = this._currentElement.type;
    var constructor = this._instance && this._instance.constructor;
    return type.displayName || constructor && constructor.displayName || type.name || constructor && constructor.name || null;
  },

  /**
   * Get the publicly accessible representation of this component - i.e. what
   * is exposed by refs and returned by render. Can be null for stateless
   * components.
   *
   * @return {ReactComponent} the public component instance.
   * @internal
   */
  getPublicInstance: function () {
    var inst = this._instance;
    if (this._compositeType === CompositeTypes.StatelessFunctional) {
      return null;
    }
    return inst;
  },

  // Stub
  _instantiateReactComponent: null
};

module.exports = ReactCompositeComponent;