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Discussion on: The Revealing Module Pattern in JavaScript

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brunnerlivio profile image
Livio Brunner • Edited

I would not say its directly an alternative to ES6 classes since they need to be instantiated and can have its own context per instance. With this example, you will share the context with every call, similar to a static class. In fact, if you have the following example in TypeScript or ES6:

class clarkKent {
  private static fullname = 'Clark Kent';
  private static secretIdentiy = 'Superman';
  static introduce() {
    return `Hi, my name is ${this.fullname}`;
  }

  static issueReport() {
    return `${this.secretIdentiy} saves the day!`;
  }
}

and you compile it to ES5, you will end up with almost the same code as the author described.

var clarkKent = /** @class */ (function () {
    function clarkKent() {
    }
    clarkKent.introduce = function () {
        return "Hi, my name is " + this.fullname;
    };
    clarkKent.issueReport = function () {
        return this.secretIdentiy + " saves the day!";
    };
    clarkKent.fullname = 'Clark Kent';
    clarkKent.secretIdentiy = 'Superman';
    return clarkKent;
}());

The benefit of using this module pattern over static classes is to get rid of the this keyword. From a user perspective, they behave pretty much the same though. One thing to take into account is that ES6 static classes' private properties can be accessed if you disable the TypeScript compiler. With the module pattern, it will get very hard (if not impossible) to access those.

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pavelloz profile image
Paweł Kowalski

Im pretty sure es6 class doesnt have to be instantiated to do some of those things.

IE.

class Test {
  static hello() { console.log('world'); }
}

Test.hello(); // => 'world'
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brunnerlivio profile image
Livio Brunner

I think you are referring to:

ES6 classes since they need to be instantiated

I was not referring to static classes here :) I thought it would be clear with the rest of my comment.

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pavelloz profile image
Paweł Kowalski

Well, class is not static, it just has static methods on it, you can still do everything you do with any other class, plus you can run methods directly, which in combination gives a lot of flexibility.