CODEWITHSUNDEEP
javascript
zya
zya

Reputation: 850

Using constructor.prototype method for creating a JavaScript library

I am looking into systems for making JavaScript libraries. I have seen most of the libraries using methods such as "Immediately Invoked Function Expression". This method to me makes the code quite unreadable.

I want to know what are the advantages of using this method?

And what are limitations of using the basic .prototype system for creating a library?

For instance, what is wrong with using this pattern to create a library?:

function Library(){

  this.property = 'val';

}

Library.prototype.method = function(){
  // a method
}

//and to use the library
var lib = new Library();

Upvotes: 2

Views: 1082

Answers (1)

Mitya
Mitya

Reputation: 34556

Immediately-executed functions are essentially just a means of avoiding polluting the global scope with variables that should be private.

Your approach is fine, but what if you want your library to internally reference private data that should not be part of your public API? Example:

var Some_class = (function() {

    var foobar = 'foo'; //private; library can read it but public API can't

    var api = function() { /* constructor */ };
    api.prototype.method = function() { return foobar == 'foo' ? 1 : 0; }

    return api;

})();

var instance = new Some_class();
instance.method();

foobar is a private (i.e. internal) variable for use BY your library, but not publicly accessible via its API.

Upvotes: 2

Related Questions