https://github.com/benjamn/cls
Class factory featuring inheritance of static properties, static constructors, lazy population of prototypes, and this._super
https://github.com/benjamn/cls
Last synced: 12 months ago
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Class factory featuring inheritance of static properties, static constructors, lazy population of prototypes, and this._super
- Host: GitHub
- URL: https://github.com/benjamn/cls
- Owner: benjamn
- License: mit
- Created: 2013-06-15T18:45:13.000Z (about 13 years ago)
- Default Branch: master
- Last Pushed: 2017-03-18T16:27:06.000Z (over 9 years ago)
- Last Synced: 2025-06-12T22:18:53.447Z (about 1 year ago)
- Language: JavaScript
- Size: 10.7 KB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
Introduction
---
Standardized `class` syntax
[is coming](http://wiki.ecmascript.org/doku.php?id=strawman:maximally_minimal_classes)
in ECMAScript 6, supposedly, but until then I need a class factory that fills the gap.
For me that means (in no particular order):
* prototypal inheritance under the hood
* access to overridden properties (`super`)
* inheritance of `static` properties
* `static` constructors
* close correspondence to ES6 syntax
* ES5/browser compatibility
* only-pay-for-what-you-use performance
* excellent test coverage: [](https://travis-ci.org/benjamn/cls)
I have no delusions of persuading the world to use this tool. Just try
`npm search inheritance` some time to see how many other people have come
up with solutions that work for them.
If you have a special interest in the tired me-too sport of
pure-JavaScript class factory implementations, you might find this one
interesting for its solutions to each of the requirements listed above,
particularly the lazy (just-in-time) population of prototype properties.
Note that I did not mention privacy enforcement as a requirement. If you
need a mechanism like the `private` keyword in other languages, I have a
separate [project](https://npmjs.org/package/private) that works
seamlessly alongside this one.
Installation
---
From NPM:
npm install cls
From GitHub:
cd path/to/node_modules
git clone git://github.com/benjamn/cls.git
cd cls
npm install .
Usage
---
One example will have to suffice for now:
```js
var cls = require("cls");
var BaseClass = cls.extend({
init: function(a, b) {
this.sum = a + b;
},
getSum: function() {
return this.sum;
},
statics: {
name: "BaseClass",
init: function(cls) {
cls.zero = new cls(0, 0);
}
}
});
var SubClass = BaseClass.extend({
init: function(arg) {
this._super(arg, arg);
this.sum += 1;
},
statics: {
name: "SubClass"
}
});
assert(BaseClass.name === "BaseClass");
assert(SubClass.name === "SubClass");
assert(new BaseClass(2).getSum() === 4);
assert(new SubClass(2).getSum() === 5);
assert(SubClass.zero !== BaseClass.zero);
assert(SubClass.zero instanceof SubClass);
assert(SubClass.zero.getSum() === 1);
```
For more complex examples, see `test/run.js`.