optionjs

optionjs

Option manager for javascript components.

Why

Optionjs handles options creation using default values and read/write operations. The most interesting part of using optionjs is the ability to attach handler on an option value change.

Using kind of util inside a component to read/write related options also gives more flexibility to add more options in the future without changing your shipped interfaces.

Installation

Using bower package manager:

bower install https://github.com/gghez/optionjs.git

Using npm package manager for nodejs module:

npm install optionjs

Usage

You can use optionjs as client side javascript resource as well as nodejs module.

Client side (Regular/HTML JS)

Reference optionjs.js script:

<script src="bower_components/optionjs/src/optionjs.js"></script>

Assuming you create a prototype which needs to be configurable using option list. Optionjs replaces option management logical layer. Use optionjs this way:

// onOpt1Change handler
function onOpt1Change(newValue, oldValue) {
    console.log('opt1 option value changed from', opt1OldValue, 'to', opt1NewValue);
}

// Constructor
var MyProto = function(options) {
    this.options = new OptionsManager(options, {
        'opt1': 'opt1 default value',
        'opt2': null
    });

    // An opt1 value change raises onOpt1Change function.
    this.options.onChange('opt1', onOpt1Change);
};

// Getter / Setter example
MyProto.prototype.options = function(optKey, optValue) {
    if (optValue === undefined) { // Use as getter
        return this.options.get(optKey);
    } else { // Use as setter
        this.options.set(optKey, optValue);
    }
}

Server side (NodeJS)

var optionjs = require('optionjs');

var options = optionjs(
    { opt1: 'string1', opt3: 'string3'},
    { opt2: 'default string 2' }
);

console.log(options.get('opt1')); // string 1
console.log(options.get('opt2')); // default string 2

API

###OptionsManager(options, defaults) Constructor creates a new instance of OptionsManager. Example:

var options = OptionsManager(
  {opt1: 'string1', opt3: null},
  {opt2: 'string2', opt3: 'string3'});

console.log(options.get('opt1')); // string1
console.log(options.get('opt2')); // string2
console.log(options.get('opt3')); // null

Parameter	Description
options	Options object using keys as option names and values as option values.
defaults	Options object used to complete options on non-existing option name.

###.get(optKey) Retrieves an option value given its name (optKey).

###.set(optKey, optValue) Defines or overrides existing option given its name (optKey) and new value (optValue).

###.onChange(optKey, handler) Attach an event handler called each time option has its value changed.

Parameter	Description
optKey	The option name.
handler	A user defined function called with respectively new value and old value of option on which it has been attached.

###.hasChangeHandler(optKey) Indicates whether option named optKey has an attached handler spying its value changes. Returns true or false only.

##Development

1. Clone git repository

git clone https://github.com/gghez/optionjs.git

1. Installation

npm install

1. Run tests

   a. Continuous integration

   grunt run

   b. One time

   grunt test

License

MIT