Plain Javascript as Angular 2 service

Update 1: Based on the comments, the previous solution will be not help you.

You can do that by using OpaqueToken in Angular2

1. Create a Token that is used to find an instance as below in a separate ts file.

import { OpaqueToken } from '@angular/core'

export let name_of_The_Token = new OpaqueToken('name_Of_The_Window_Object');

2. In your App.module, you need to import and declare a variable that is the name of your window object which makes the Token as a angular2 service so that you can use properties, methods in that javascript file across your components.

import { name_of_The_Token } from '/* file_Path */';
declare let name_Of_The_Window_Object : any;  //below your import statements

Step 3: Inject it to providers array of your module.

{ provide : name_of_The_Token , useValue : name_Of_The_Window_Object }

Guidance to use this token in components

1. Import the token just like any other service and @Inject from angular-core

    import { name_of_The_Token } from '/* file_Path */';
    import { Inject } from '@angular/core';
   

2. In constructor of the component

    constructor(@Inject( name_of_The_Token ) private _serviceObject : any )       
   

3. Any where in your component you can use the variables and methods of your javascript file as

    this._serviceObject.method1()
    this._serviceObject.variable1
    .....
   

Note: One drawback is that you will not get intellisense.

Overcoming it:
If you are looking for intellisense you need to wrap the methods and variables inside an interface and use it in the type**(instead of any)** of your token as

export interface myCustom {
      method1(args): return_Type;
      method2(args): void;
      .....
   }

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