defineSetters and defineGetters

def_getters_setters.js

"use strict"

/*exported defineGetters*/

/**
 * Applies a function as the getter function for all the custom properties
 * of a component named in an array.
 * This is useful to avoid repeating yourself when the getter for two or more
 * custom properties is the same —e.g.
 * <pre><code>
 * 	defineGetters(this, ['foo','bar'], prop => { return this['_' + prop] })
 * </code></pre>
 *
 * @param {Controller} ctrl - The controller of the component for which the custom properties are defined.
 * @param {Array} props - The array of the properties for which the getter will be set.
 * @param {Function} getter - The function that will be defined as the getter for the properties mentioned in the array.
 */
const defineGetters = (ctrl, props, getter) => {
	props.forEach((prop/*, i, arr*/) => {
		/*globals defineGetter*/
		defineGetter(ctrl, prop, () => {
			getter.call(ctrl, prop)
		})
	})
}

/*exported defineSetters*/

/**
 * Applies a function as the setter function for all the custom properties
 * of a component named in an array.
 * This is useful to avoid repeating yourself when the setter for two or more
 * custom properties is the same —e.g.
 * <pre><code>
 * 	defineSetters(this, ['foo','bar'], (value, prop) => { this['_' + prop] = value })
 * </code></pre>
 *
 * @param {Controller} ctrl - The controller of the component for which the custom properties are defined.
 * @param {Array} props - The array of the properties for which the setter will be set.
 * @param {Function} setter - The function that will be defined as the setter for the properties mentioned in the array.
 */
const defineSetters = (ctrl, props, setter) => {
	props.forEach((prop/*, i, arr*/) => {
		/*global defineSetter*/
		defineSetter(ctrl, prop, (value) => {
			setter.call(ctrl, value, prop)
		})
	})
}

//Then, in a component, just define something like:

initGettersSetters: function() {

	/*globals defineSetters defineGetters*/
	const stringProps = ['foo', 'bar']
	defineSetters(this, stringProps, (value, prop) => {
		this['_' + prop] = value
	})

	const floatProps = ['qux', 'baz']
	defineSetters(this, floatProps, (value, prop) => {
		this['_' + prop] = parseFloat(value || 0)
	})

	const allProps = stringProps.concat(floatProps)
	defineGetters(this, allProps, prop => {
		return this['_' + prop]
	})
}