plainToClass to call object.method() in web worker thread

Question

I am using angular, trying to pass an object to the web worker for the background process. the class is

Article{
  method1();
  propertyA;
}

addEventListener('message', ({ data }) => {
  // if without plainToClass, how to call article.method1()
  data.article=plainToClass(Article, data.article);
  console.log(data.article.method1());
});

Because in the web worker thread, I want to use article.method1(),

1. After the object is passed to web worker, it becomes an object that does not have methods but only properties. Why is this? pass as a string?

2. Tried to use plainToClass() to convert the passed obj to an Object with method, which in main thread I am able to do so, load string and convert to Class object. but in web worker, it complains about Reflect.getMetadata is not a function . Which seems it cannot find the imported import 'reflect-metadata' in polyfills.ts

Answer:

It turns out I need to import this in Article class file

import 'reflect-metadata';
export class Article implements Clonable{
}

Answer 1

Passing data to a Web worker is done by serializing the object , so you won't be able to pass in behavior. Instead, you'll need to either use plainToClass as you have in your example, or you can provide the functionality in a helper function.

Additionally, import reflect-metadata is an import for side-effects. This code is run once per context , so it will need to be run again inside the worker , and then plainToClass should work.

That said, a simpler approach might be to try to call the class constructor using the values passed in - if that's possible?