react/src/classic/element/ReactElementValidator.js

/**
 * Copyright 2014-2015, 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.
 *
 * @providesModule ReactElementValidator
 */

/**
 * ReactElementValidator provides a wrapper around a element factory
 * which validates the props passed to the element. This is intended to be
 * used only in DEV and could be replaced by a static type checker for languages
 * that support it.
 */

'use strict';

var ReactElement = require('ReactElement');
var ReactFragment = require('ReactFragment');
var ReactPropTypeLocations = require('ReactPropTypeLocations');
var ReactPropTypeLocationNames = require('ReactPropTypeLocationNames');
var ReactCurrentOwner = require('ReactCurrentOwner');
var ReactNativeComponent = require('ReactNativeComponent');

var getIteratorFn = require('getIteratorFn');
var monitorCodeUse = require('monitorCodeUse');
var invariant = require('invariant');
var warning = require('warning');

function getDeclarationErrorAddendum() {
  if (ReactCurrentOwner.current) {
    var name = ReactCurrentOwner.current.getName();
    if (name) {
      return ' Check the render method of `' + name + '`.';
    }
  }
  return '';
}

/**
 * Warn if there's no key explicitly set on dynamic arrays of children or
 * object keys are not valid. This allows us to keep track of children between
 * updates.
 */
var ownerHasKeyUseWarning = {
  'react_key_warning': {},
  'react_numeric_key_warning': {}
};
var ownerHasMonitoredObjectMap = {};

var loggedTypeFailures = {};

var NUMERIC_PROPERTY_REGEX = /^\d+$/;

/**
 * Gets the instance's name for use in warnings.
 *
 * @internal
 * @return {?string} Display name or undefined
 */
function getName(instance) {
  var publicInstance = instance && instance.getPublicInstance();
  if (!publicInstance) {
    return undefined;
  }
  var constructor = publicInstance.constructor;
  if (!constructor) {
    return undefined;
  }
  return constructor.displayName || constructor.name || undefined;
}

/**
 * Gets the current owner's displayName for use in warnings.
 *
 * @internal
 * @return {?string} Display name or undefined
 */
function getCurrentOwnerDisplayName() {
  var current = ReactCurrentOwner.current;
  return (
    current && getName(current) || undefined
  );
}

/**
 * Warn if the element doesn't have an explicit key assigned to it.
 * This element is in an array. The array could grow and shrink or be
 * reordered. All children that haven't already been validated are required to
 * have a "key" property assigned to it.
 *
 * @internal
 * @param {ReactElement} element Element that requires a key.
 * @param {*} parentType element's parent's type.
 */
function validateExplicitKey(element, parentType) {
  if (element._store.validated || element.key != null) {
    return;
  }
  element._store.validated = true;

  warnAndMonitorForKeyUse(
    'react_key_warning',
    'Each child in an array or iterator should have a unique "key" prop.',
    element,
    parentType
  );
}

/**
 * Warn if the key is being defined as an object property but has an incorrect
 * value.
 *
 * @internal
 * @param {string} name Property name of the key.
 * @param {ReactElement} element Component that requires a key.
 * @param {*} parentType element's parent's type.
 */
function validatePropertyKey(name, element, parentType) {
  if (!NUMERIC_PROPERTY_REGEX.test(name)) {
    return;
  }
  warnAndMonitorForKeyUse(
    'react_numeric_key_warning',
    'Child objects should have non-numeric keys so ordering is preserved.',
    element,
    parentType
  );
}

/**
 * Shared warning and monitoring code for the key warnings.
 *
 * @internal
 * @param {string} warningID The id used when logging.
 * @param {string} message The base warning that gets output.
 * @param {ReactElement} element Component that requires a key.
 * @param {*} parentType element's parent's type.
 */
function warnAndMonitorForKeyUse(warningID, message, element, parentType) {
  var ownerName = getCurrentOwnerDisplayName();
  var parentName = parentType.displayName || parentType.name;

  var useName = ownerName || parentName;
  var memoizer = ownerHasKeyUseWarning[warningID];
  if (memoizer.hasOwnProperty(useName)) {
    return;
  }
  memoizer[useName] = true;

  message += ownerName ?
    ` Check the render method of ${ownerName}.` :
    ` Check the React.render call using <${parentName}>.`;

  // Usually the current owner is the offender, but if it accepts children as a
  // property, it may be the creator of the child that's responsible for
  // assigning it a key.
  var childOwnerName = null;
  if (element &&
      element._owner &&
      element._owner !== ReactCurrentOwner.current) {
    // Name of the component that originally created this child.
    childOwnerName = getName(element._owner);

    message += ` It was passed a child from ${childOwnerName}.`;
  }

  message += ' See http://fb.me/react-warning-keys for more information.';
  monitorCodeUse(warningID, {
    component: useName,
    componentOwner: childOwnerName
  });
  console.warn(message);
}

/**
 * Ensure that every element either is passed in a static location, in an
 * array with an explicit keys property defined, or in an object literal
 * with valid key property.
 *
 * @internal
 * @param {ReactNode} node Statically passed child of any type.
 * @param {*} parentType node's parent's type.
 */
function validateChildKeys(node, parentType) {
  if (Array.isArray(node)) {
    for (var i = 0; i < node.length; i++) {
      var child = node[i];
      if (ReactElement.isValidElement(child)) {
        validateExplicitKey(child, parentType);
      }
    }
  } else if (ReactElement.isValidElement(node)) {
    // This element was passed in a valid location.
    node._store.validated = true;
  } else if (node) {
    var iteratorFn = getIteratorFn(node);
    // Entry iterators provide implicit keys.
    if (iteratorFn) {
      if (iteratorFn !== node.entries) {
        var iterator = iteratorFn.call(node);
        var step;
        while (!(step = iterator.next()).done) {
          if (ReactElement.isValidElement(step.value)) {
            validateExplicitKey(step.value, parentType);
          }
        }
      }
    } else if (typeof node === 'object') {
      var fragment = ReactFragment.extractIfFragment(node);
      for (var key in fragment) {
        if (fragment.hasOwnProperty(key)) {
          validatePropertyKey(key, fragment[key], parentType);
        }
      }
    }
  }
}

/**
 * Assert that the props are valid
 *
 * @param {string} componentName Name of the component for error messages.
 * @param {object} propTypes Map of prop name to a ReactPropType
 * @param {object} props
 * @param {string} location e.g. "prop", "context", "child context"
 * @private
 */
function checkPropTypes(componentName, propTypes, props, location) {
  for (var propName in propTypes) {
    if (propTypes.hasOwnProperty(propName)) {
      var error;
      // Prop type validation may throw. In case they do, we don't want to
      // fail the render phase where it didn't fail before. So we log it.
      // After these have been cleaned up, we'll let them throw.
      try {
        // This is intentionally an invariant that gets caught. It's the same
        // behavior as without this statement except with a better message.
        invariant(
          typeof propTypes[propName] === 'function',
          '%s: %s type `%s` is invalid; it must be a function, usually from ' +
          'React.PropTypes.',
          componentName || 'React class',
          ReactPropTypeLocationNames[location],
          propName
        );
        error = propTypes[propName](props, propName, componentName, location);
      } catch (ex) {
        error = ex;
      }
      if (error instanceof Error && !(error.message in loggedTypeFailures)) {
        // Only monitor this failure once because there tends to be a lot of the
        // same error.
        loggedTypeFailures[error.message] = true;

        var addendum = getDeclarationErrorAddendum(this);
        warning(false, 'Failed propType: ' + error.message + addendum);
      }
    }
  }
}

var warnedPropsMutations = {};

/**
 * Warn about mutating props when setting `propName` on `element`.
 *
 * @param {string} propName The string key within props that was set
 * @param {ReactElement} element
 */
function warnForPropsMutation(propName, element) {
  var type = element.type;
  var elementName = typeof type === 'string' ? type : type.displayName;
  var ownerName = element._owner ?
    element._owner.getPublicInstance().constructor.displayName : null;

  var warningKey = propName + '|' + elementName + '|' + ownerName;
  if (warnedPropsMutations.hasOwnProperty(warningKey)) {
    return;
  }
  warnedPropsMutations[warningKey] = true;

  var elementInfo = '';
  if (elementName) {
    elementInfo = ' <' + elementName + ' />';
  }
  var ownerInfo = '';
  if (ownerName) {
    ownerInfo = ' The element was created by ' + ownerName + '.';
  }

  warning(
    false,
    'Don\'t set .props.%s of the React component%s. ' +
    'Instead, specify the correct value when ' +
    'initially creating the element.%s',
    propName,
    elementInfo,
    ownerInfo
  );
}

/**
 * Given an element, check if its props have been mutated since element
 * creation (or the last call to this function). In particular, check if any
 * new props have been added, which we can't directly catch by defining warning
 * properties on the props object.
 *
 * @param {ReactElement} element
 */
function checkAndWarnForMutatedProps(element) {
  if (!element._store) {
    // Element was created using `new ReactElement` directly or with
    // `ReactElement.createElement`; skip mutation checking
    return;
  }

  var originalProps = element._store.originalProps;
  var props = element.props;

  for (var propName in props) {
    if (props.hasOwnProperty(propName)) {
      if (!originalProps.hasOwnProperty(propName) ||
          originalProps[propName] !== props[propName]) {
        warnForPropsMutation(propName, element);

        // Copy over the new value so that the two props objects match again
        originalProps[propName] = props[propName];
      }
    }
  }
}

var ReactElementValidator = {

  checkAndWarnForMutatedProps: checkAndWarnForMutatedProps,

  createElement: function(type, props, children) {
    // We warn in this case but don't throw. We expect the element creation to
    // succeed and there will likely be errors in render.
    warning(
      type != null,
      'React.createElement: type should not be null or undefined. It should ' +
        'be a string (for DOM elements) or a ReactClass (for composite ' +
        'components).'
    );

    var element = ReactElement.createElement.apply(this, arguments);

    // The result can be nullish if a mock or a custom function is used.
    // TODO: Drop this when these are no longer allowed as the type argument.
    if (element == null) {
      return element;
    }

    for (var i = 2; i < arguments.length; i++) {
      validateChildKeys(arguments[i], type);
    }

    if (type) {
      // Extract the component class from the element. Converts string types
      // to a composite class which may have propTypes.
      // TODO: Validating a string's propTypes is not decoupled from the
      // rendering target which is problematic.
      var componentClass = ReactNativeComponent.getComponentClassForElement(
        element
      );
      var name = componentClass.displayName || componentClass.name;
      if (__DEV__) {
        if (componentClass.propTypes) {
          checkPropTypes(
            name,
            componentClass.propTypes,
            element.props,
            ReactPropTypeLocations.prop
          );
        }
      }
      if (typeof componentClass.getDefaultProps === 'function') {
        warning(
          componentClass.getDefaultProps.isReactClassApproved,
          'getDefaultProps is only used on classic React.createClass ' +
          'definitions. Use a static property named `defaultProps` instead.'
        );
      }
    }

    return element;
  },

  createFactory: function(type) {
    var validatedFactory = ReactElementValidator.createElement.bind(
      null,
      type
    );
    // Legacy hook TODO: Warn if this is accessed
    validatedFactory.type = type;
    return validatedFactory;
  }

};

module.exports = ReactElementValidator;