readme.md

option-chain

Use fluent property chains in lieu of options objects

Install

$ npm install option-chain

Usage

const optionChain = require('option-chain');

const optionDefinition = {
	defaults: {
		bar: false
	},
	chainableMethods: {
		foo: {foo: true},
		notFoo: {foo: false},
		bar: {bar: true}
	}
};

function printOptionsAndArgs(options, args) {
	console.log(options);

	if (args.length) {
		console.log(args);
	}
}

const fn = optionChain(optionDefinition, printOptionsAndArgs);

fn();
//=> [{bar: false}]
fn.bar();
//=> [{bar: true}]
fn.foo.bar();
//=> [{foo: true, bar: false}]

fn.foo('a', 'b');
//=> [{foo: true, bar: false}]
//=> ['a', 'b']

API

optionChain(options, callback, target?)

options

Type: object

chainableMethods

Required
Type: object

A map of chainable property names to the options set by adding property to the chain.

Given the following:

const chainableMethods = {
	foo: {foo: true},
	notFoo: {foo: false},
	bar: {bar: true},
	both: {foo: true, bar: true}
}

Then:

• fn.foo would set foo to true.
• fn.bar would set bar to true.
• fn.both sets both foo and bar to true.
• The last property in the chain takes precedence, so fn.foo.notFoo would result in foo being false.

defaults

Type: object
Default: {}

A set of default starting properties.

spread

Type: boolean
Default: false

By default, any arguments passed to the wrapper are passed as an array to the second argument of the wrapped function. When this is true, additional arguments will be spread out as additional arguments:

function withoutSpread(opts, args) {
	let foo = args[0];
	let bar = args[1];
	// …
}

function withSpread(opts, foo, bar) {
	// …
}

callback

Type: Function

This callback is called with the accumulated options as the first argument. Depending on the value of options.spread, arguments passed to the wrapper will either be an array as the second argument or spread out as the 2nd, 3rd, 4th... arguments.

target

If supplied, the target object is extended with the property getters and returned. Otherwise a wrapper function is created for options.defaults, then that wrapper is extended and returned.

Hint: If you want to extend a target and add a method that simply uses the defaults, add a chainable method definition with an empty spec:

const chainableMethods = {
	defaultMethodName: {}
}