react-native/Libraries/ReactNative/ReactNativeTextComponent.js

/**
 * Copyright (c) 2015-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.
 *
 * @providesModule ReactNativeTextComponent
 */

'use strict';

var ReactNativeTagHandles = require('ReactNativeTagHandles');
var UIManager = require('UIManager');

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

var ReactNativeTextComponent = function(props) {
  // This constructor and its argument is currently used by mocks.
};

assign(ReactNativeTextComponent.prototype, {

  construct: function(text) {
    // This is really a ReactText (ReactNode), not a ReactElement
    this._currentElement = text;
    this._stringText = '' + text;
    this._rootNodeID = null;
  },

  mountComponent: function(rootID, transaction, context) {
    invariant(
      context.isInAParentText,
      'RawText "' + this._stringText + '" must be wrapped in an explicit ' +
        '<Text> component.'
    );
    this._rootNodeID = rootID;
    var tag = ReactNativeTagHandles.allocateTag();
    var nativeTopRootID = ReactNativeTagHandles.getNativeTopRootIDFromNodeID(rootID);
    UIManager.createView(
      tag,
      'RCTRawText',
      nativeTopRootID ? ReactNativeTagHandles.rootNodeIDToTag[nativeTopRootID] : null,
      {text: this._stringText}
    );
    return {
      rootNodeID: rootID,
      tag: tag,
    };
  },

  receiveComponent: function(nextText, transaction, context) {
    if (nextText !== this._currentElement) {
      this._currentElement = nextText;
      var nextStringText = '' + nextText;
      if (nextStringText !== this._stringText) {
        this._stringText = nextStringText;
        UIManager.updateView(
          ReactNativeTagHandles.mostRecentMountedNodeHandleForRootNodeID(
            this._rootNodeID
          ),
          'RCTRawText',
          {text: this._stringText}
        );
      }
    }
  },

  unmountComponent: function() {
    this._currentElement = null;
    this._stringText = null;
    this._rootNodeID = null;
  }

});

module.exports = ReactNativeTextComponent;