JarCasting
d
Property descriptor factory
Originally derived from d package.
Defining properties with descriptors is very verbose:
var Account = function () {};
Object.defineProperties(Account.prototype, {
deposit: {
value: function () {
/* ... */
},
configurable: true,
enumerable: false,
writable: true
},
withdraw: {
value: function () {
/* ... */
},
configurable: true,
enumerable: false,
writable: true
},
balance: {
get: function () {
/* ... */
},
configurable: true,
enumerable: false
}
});
D cuts that to:
var d = require("d");
var Account = function () {};
Object.defineProperties(Account.prototype, {
deposit: d(function () {
/* ... */
}),
withdraw: d(function () {
/* ... */
}),
balance: d.gs(function () {
/* ... */
})
});
By default, created descriptor follow characteristics of native ES5 properties, and defines values as:
{ configurable: true, enumerable: false, writable: true }
You can overwrite it by preceding value argument with instruction:
d("c", value); // { configurable: true, enumerable: false, writable: false }
d("ce", value); // { configurable: true, enumerable: true, writable: false }
d("e", value); // { configurable: false, enumerable: true, writable: false }
// Same way for get/set:
d.gs("e", value); // { configurable: false, enumerable: true }
Installation
$ npm install d
To port it to Browser or any other (non CJS) environment, use your favorite CJS bundler. No favorite yet? Try: Browserify, Webmake or Webpack
Other utilities
autoBind(obj, props) (d/auto-bind)
Define methods which will be automatically bound to its instances
var d = require('d');
var autoBind = require('d/auto-bind');
var Foo = function () { this._count = 0; };
Object.defineProperties(Foo.prototype, autoBind({
increment: d(function () { ++this._count; });
}));
var foo = new Foo();
// Increment foo counter on each domEl click
domEl.addEventListener('click', foo.increment, false);
lazy(obj, props) (d/lazy)
Define lazy properties, which will be resolved on first access
var d = require("d");
var lazy = require("d/lazy");
var Foo = function () {};
Object.defineProperties(Foo.prototype, lazy({ items: d(function () { return []; }) }));
var foo = new Foo();
foo.items.push(1, 2); // foo.items array created and defined directly on foo
Tests
$ npm test
Security contact information
To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.
Get professional support for d with a Tidelift subscription
Tidelift helps make open source sustainable for maintainers while giving companies
assurances about security, maintenance, and licensing for their dependencies.
Tidelift helps make open source sustainable for maintainers while giving companies
assurances about security, maintenance, and licensing for their dependencies.