How to represent Javascript object creation with an UML class diagram?

javascript object uml class-diagram prototype-programming
Pavel Maximov picture Pavel Maximov · Feb 4, 2014 · Viewed 17.2k times · Source

I'm having some trouble drawing an accurate UML Class diagram for my JavaScript APP. I've read several UML reference resources, but still didn't find an answer for my situation, since all the examples are based on the classical inheritance and class model of C++/Java.

I want to represent the creation of a custom JavaScript object with a constructor function and extension of it's prototype object, which is quite different from C++/Java class instantiation.

How would you represent this simplified version of my code with an UML class diagram?

var Book = function(title, author) {
    this.title = title || 'No title specified';
    this.author = author || 'No author specified';
}

Book.prototype.isDigital = false;

Book.prototype.titleDisplay = function() {
    alert(this.title);
};

var theHobbit = new Book ("The Hobbit", "J.R.R. Tolkien");

NOTE: I'm especially aiming to show in the diagram how exactly all the involved objects (Book, Book.prototype and theHobbit) are related to each other and to show which parameters are defined in the prototype vs those defined in the constructor. I know I could just pretend Book is a "classical" class, and draw it like it was Java, simplifying the particular JavaScript inheritance mechanism, but I'm sure UML is flexible enough to describe precisely my case.

Is there maybe a UML guide especially for JavaScript projects?

Answer

Josh picture Josh · Feb 5, 2014

I would take a look at Object Playground.

It will create a diagram that exactly shows what is going on in your JS object hierarchy.

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