react-native/Libraries/Image/nativeImageSource.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 * @format
 */

'use strict';

const Platform = require('Platform');

// TODO: Change `nativeImageSource` to return this type.
export type NativeImageSource = {|
  +deprecated: true,
  +height: number,
  +uri: string,
  +width: number,
|};

type NativeImageSourceSpec = {|
  +android?: string,
  +ios?: string,

  // For more details on width and height, see
  // http://facebook.github.io/react-native/docs/images.html#why-not-automatically-size-everything
  +height: number,
  +width: number,
|};

/**
 * In hybrid apps, use `nativeImageSource` to access images that are already
 * available on the native side, for example in Xcode Asset Catalogs or
 * Android's drawable folder.
 *
 * However, keep in mind that React Native Packager does not guarantee that the
 * image exists. If the image is missing you'll get an empty box. When adding
 * new images your app needs to be recompiled.
 *
 * Prefer Static Image Resources system which provides more guarantees,
 * automates measurements and allows adding new images without rebuilding the
 * native app. For more details visit:
 *
 *   http://facebook.github.io/react-native/docs/images.html
 *
 */
function nativeImageSource(spec: NativeImageSourceSpec): Object {
  let uri = Platform.select(spec);
  if (uri == null) {
    console.warn(
      'nativeImageSource(...): No image name supplied for `%s`:\n%s',
      Platform.OS,
      JSON.stringify(spec, null, 2),
    );
    uri = '';
  }
  return {
    deprecated: true,
    height: spec.height,
    uri,
    width: spec.width,
  };
}

module.exports = nativeImageSource;