CocktailJS is a small library for NodeJS to help developers defining classes and modules in a better, more readable and organised way. It also explores other technics to reuse code such as Annotations, Traits and Talents.
For those developers who likes Object Oriented Programming, CocktailJS helps to extend your classes without utils, to define modules, and to keep code structure more visually appealing making the code easier to understand and debug.
There is one principle behind CocktailJS's design: Keep code simple, readable and reusable. Simplicity is key in any design, and writing code is not an exception to that rule.
The entry point in Cocktail is a method named mix(). As in any cocktail, you mix things up. In the mix we can use an existing Object, Module or Class reference and mix it to add more value, like adding more properties or even methods.
Mix Object Example
var cocktail = require('cocktail'),
obj = {
name: 'My Object'
};
cocktail.mix(obj, {
value: 10,
print: function() {
console.log(this.name + ' ' + this.value);
}
});
obj.print(); //MyObject 10
Read more: Quick Start
Annotations are meta-data CocktailJS uses to apply some processes. As meta-data, they are not part of the resulting mix, they are declarative and they bring readability on your code.
A Class Example (Car.js)
var cocktail = require('cocktail');
cocktail.mix({
'@exports': module,
'@as': 'class',
'@properties': {
make: '',
model: '',
year: null
},
constructor: function(make, model, year) {
this.setMake(make);
this.setModel(model);
this.setYear(year);
}
});
Read more: Class Definitions
Traits are Composable Units of Behaviour (You can read more from this paper). Basically, a Trait is a Class, but a special type of Class that has only behaviour (methods) and no state. Traits are an alternative to reuse behaviour in a more predictable manner. They are more robust than Mixins, or Multiple Inheritance since name collisions must be solved by the developer beforehand. If you compose your class with one or more Traits and you have a method defined in more than one place, your program will fail giving no magic rule or any kind of precedence definition.
var cocktail = require('cocktail'),
Login = require('./trait/login');
cocktail.mix({
'@exports': module,
'@as': 'class',
'@traits': [Login]
});
Read More: Starting with Traits
Talents are very similar to Traits, in fact a Trait can be applied as a Talent in CocktailJS. The main difference is that a Talent can be applied to an object or module. So we can define a Talent as a Dynamically Composable Unit of Reuse (you can read more from this paper).
Note: While almost all functionality is implemented, the only missing part from the original paper is the ability to remove a Talent from a given instance.
var cocktail = require('cocktail'),
Login = require('./trait/login'),
user = require('./user');
cocktail.mix(user, {
'@talents': [Login]
});
Read More: Exploring Talents
Use npm to install and save it to your project.
$ npm install cocktail --save
CocktailJS is a very versatile library. You can follow the single argument class definition where you can define your properties and methods, extend from another class, mix traits and export the class all in one single operation. But sometimes you already have a module definition where you want to keep the current code style. In this post we are going to explore how to use Traits or Talents in an exisiting class definition.
JavaScript has five primitive data types: String, Number, Boolean, Null and Undefined. All of these are inmutable, meaning that their values cannot be changed, while Objects, Array, Date, and others are mutable.
This post is intended to show a very subtle difference while defining properties values for a Class inside a prototype versus in the constructor.
TL;DR Do not define mutable properties (Object, Array, Date, etc) in the prototype.
We are happy to announce a new version of CocktailJS! CocktailJS v0.5.0 is available on npm!
With this new release we added more functionality to cocktail by adding a new way to create, use and share custom annotations. We also improved the code by refactoring some internals to avoid duplicated code, fixed some issues and we have added some tests too.
But that's not all. We have created a few CocktailJS Extensions and you can expect more of them to be released in a near future.