ReactNativeComponent.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 ReactNativeComponent
 */

'use strict';

var assign = require('Object.assign');
var invariant = require('invariant');

var autoGenerateWrapperClass = null;
var genericComponentClass = null;
// This registry keeps track of wrapper classes around native tags
var tagToComponentClass = {};
var textComponentClass = null;

var ReactNativeComponentInjection = {
  // This accepts a class that receives the tag string. This is a catch all
  // that can render any kind of tag.
  injectGenericComponentClass: function(componentClass) {
    genericComponentClass = componentClass;
  },
  // This accepts a text component class that takes the text string to be
  // rendered as props.
  injectTextComponentClass: function(componentClass) {
    textComponentClass = componentClass;
  },
  // This accepts a keyed object with classes as values. Each key represents a
  // tag. That particular tag will use this class instead of the generic one.
  injectComponentClasses: function(componentClasses) {
    assign(tagToComponentClass, componentClasses);
  },
  // Temporary hack since we expect DOM refs to behave like composites,
  // for this release.
  injectAutoWrapper: function(wrapperFactory) {
    autoGenerateWrapperClass = wrapperFactory;
  }
};

/**
 * Get a composite component wrapper class for a specific tag.
 *
 * @param {ReactElement} element The tag for which to get the class.
 * @return {function} The React class constructor function.
 */
function getComponentClassForElement(element) {
  if (typeof element.type === 'function') {
    return element.type;
  }
  var tag = element.type;
  var componentClass = tagToComponentClass[tag];
  if (componentClass == null) {
    tagToComponentClass[tag] = componentClass = autoGenerateWrapperClass(tag);
  }
  return componentClass;
}

/**
 * Get a native internal component class for a specific tag.
 *
 * @param {ReactElement} element The element to create.
 * @return {function} The internal class constructor function.
 */
function createInternalComponent(element) {
  invariant(
    genericComponentClass,
    'There is no registered component for the tag %s',
    element.type
  );
  return new genericComponentClass(element.type, element.props);
}

/**
 * @param {ReactText} text
 * @return {ReactComponent}
 */
function createInstanceForText(text) {
  return new textComponentClass(text);
}

/**
 * @param {ReactComponent} component
 * @return {boolean}
 */
function isTextComponent(component) {
  return component instanceof textComponentClass;
}

var ReactNativeComponent = {
  getComponentClassForElement: getComponentClassForElement,
  createInternalComponent: createInternalComponent,
  createInstanceForText: createInstanceForText,
  isTextComponent: isTextComponent,
  injection: ReactNativeComponentInjection
};

module.exports = ReactNativeComponent;