https://github.com/tchar/js-singleton
A singleton wrapper for creating single instances of functions.
https://github.com/tchar/js-singleton
Last synced: 6 months ago
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A singleton wrapper for creating single instances of functions.
- Host: GitHub
- URL: https://github.com/tchar/js-singleton
- Owner: tchar
- License: mit
- Created: 2017-12-17T14:01:10.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-12-17T18:42:07.000Z (over 8 years ago)
- Last Synced: 2025-10-27T15:58:44.414Z (9 months ago)
- Language: JavaScript
- Size: 12.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# js-singleton
A singleton wrapper for creating single instances of functions.
This module can wrap an arbitrary number of functions in the same
Singleton meaning you can init everything you need and then just
use `require('js-singleton');` in other modules and it will work just fine.
# Examples
## Simple example in multi mode
```javascript
const Singleton = require('js-singleton')();
function Person(firstname, lastname){
this.firstname = firstname;
this.lastname = lastname;
}
var person = Singleton.getInstance(Person, 'George', 'Clooney');
console.log(person.firstname, person.lastname); // Prints George Clooney
var anotherPerson = Singleton.getInstance(Person, 'Michael', 'Jackson');
console.log(anotherPerson.firstname, anotherPerson.lastname); // Prints George Clooney
var anotherPersonMaybe = Singleton.getInstance(Person);
console.log(anotherPersonMaybe.firstname, anotherPersonMaybe.lastname); // Prints George Clooney
```
## Simple example in single mode
```javascript
function ff(d){
this.d = d;
}
const SingletonSingle = require('js-singleton')(ff, 125);
const Singleton = require('js-singleton')();
var i1 = SingletonSingle.getInstance();
var i2 = SingletonSingle.getInstance();
var i3 = Singleton.getInstance(ff);
console.log(i1.d); // Prints 125
console.log(i2.d); // Prints 125
console.log(i3.d); // Prints 125
```
## Example with getInstance() by passing a string alias of the function via setName()
```javascript
function Complex(a, b){
this.a = a;
this.b = b;
}
var complex = Singleton.getInstance(Complex, 1, 2);
const SingletonSingle = require('js-singleton')(Complex);
Singleton.setName("MyCustomComplexClass", Complex);
SingletonSingle.setName("MyCustomComplexClass"); // Equivalent to previous line
var anotherComplex = Singleton.getInstance("MyCustomComplexClass");
var someOtherComplex = SingletonSingle.getInstance();
console.log(anotherComplex.a, anotherComplex.b); // Prints 1 2;
console.log(complex.a, complex.b); // Prints 1 2;
console.log(someOtherComplex.a, someOtherComplex.b); // Prints 1 2;
```
## Example with creating multiple aliases for the same function via setName()
```javascript
const Singleton = require('js-singleton')();
function Door(height, width){
this.height = height;
this.width = width;
}
var door = Singleton.getInstance(Door, 1.1, 2.3);
Singleton.setName("door", Door);
Singleton.setName("door", "otherDoorAlias");
var anotherDoor = Singleton.getInstance("door");
var anotherDoorMaybe = Singleton.getInstance("otherDoorAlias");
const SingletonSingle = require('js-singleton')("otherDoorAlias)";
var aDoorAlso = SingletonSingle.getInstace();
console.log(door.width, door.height); // Prints 2.3 1.1
console.log(anotherDoor.width, anotherDoor.height); // Prints 2.3 1.1
console.log(anotherDoorMaybe.width, anotherDoorMaybe.height); // Prints 2.3 1.1
console.log(aDoorAlso.width, aDoorAlso.height); // Prints 2.3 1.1
```
## Real world example
```javascript
/**
*
* This module is the server module (server.js)
*
* @author Some Author
*
*/
function server(options){
// Some beautiful code
}
var options = {}; // some options
const Singleton = require('js-singleton')();
Singleton.getInstance(server, options);
// equivalent
const SingletonSingle = require('js-singleton')(server, options);
Singleton.setName("myServer", server);
// equivalent
SingletonSingle.setName("myServer");
// No need to module.export
/*
*
* In another file do
*
*/
require('/path/to/server');
const Singleton = require('js-singleton')();
var myServer = Singleton.getInstance("myServer");
// equivalent
const SingletonSingle = require('js-singleton')("myServer");
var myServer = SingletonSingle.getInstance();
```