thingsboard/ui-ngx/src/app/core/services/window.service.ts

///
/// Copyright © 2016-2020 The Thingsboard Authors
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///


import { isPlatformBrowser } from '@angular/common';
import { ClassProvider, FactoryProvider, InjectionToken, PLATFORM_ID, Injectable } from '@angular/core';

/* Create a new injection token for injecting the window into a component. */
export const WINDOW = new InjectionToken('WindowToken');

/* Define abstract class for obtaining reference to the global window object. */
export abstract class WindowRef {

  get nativeWindow(): Window | object {
    throw new Error('Not implemented.');
  }

}

/* Define class that implements the abstract class and returns the native window object. */
@Injectable()
export class BrowserWindowRef extends WindowRef {

  constructor() {
    super();
  }

  get nativeWindow(): Window | object {
    return window;
  }

}

/* Create an factory function that returns the native window object. */
export function windowFactory(browserWindowRef: BrowserWindowRef, platformId: object): Window | object {
  if (isPlatformBrowser(platformId)) {
    return browserWindowRef.nativeWindow;
  }
  return new Object();
}

/* Create a injectable provider for the WindowRef token that uses the BrowserWindowRef class. */
export const browserWindowProvider: ClassProvider = {
  provide: WindowRef,
  useClass: BrowserWindowRef
};

/* Create an injectable provider that uses the windowFactory function for returning the native window object. */
export const windowProvider: FactoryProvider = {
  provide: WINDOW,
  useFactory: windowFactory,
  deps: [ WindowRef, PLATFORM_ID ]
};

/* Create an array of providers. */
export const WINDOW_PROVIDERS = [
  browserWindowProvider,
  windowProvider
];