LoDash.js / Underscore.js mixins

Jonathan Stassen — Wed, 23 Sep 2015 21:44:01 +0000

Here are a few mixins I’ve created for LoDash.js I’ve found handy.

_.getDeep
/** * Safely retrieves the value of a deeply nested object value * @param {object} O The Object to be searched * @param {string} str Dot notation string of the address of the attribute to be retrieved * @return {mixed} Value of nested item or undefined * @link http://stackoverflow.com/a/15400575/417822 */ _.mixin({'getDeep': function(O, str) { if ( !_.isObject(O) ) return;


	var seg= str.split('.');

	while(O && seg.length) {

		O = O[seg.shift()];

	}

	return O;

}});

_.hasDeep


/**

 * Tests if a deep value has a value/exists. Uses _.getDeep to retrieve value.

 * @param  {object} O   The Object to be tested

 * @param  {string} str Dot notation string of the address of the attributed to be tested

 * @return {boolean}

 * @todo validate that falesy values 'false' '0' etc come back as true.

 */

_.mixin({'hasDeep': function(O, str) {

	return !_.isUndefined( _.getDeep(O, str) );

}});

_.isDefined
Because typing !_.isUndefined() all the time is tiresome. Using _.isDefined is clear and more readable.


/**

 * Shorthand for !_.isUndefined

 * @param  {mixed} e Item to be tested

 * @return {boolean}

 */

_.mixin({'isDefined': function(e) {

	return !_.isUndefined(e);

}});

_.compactObject


/**

 * Removes all falsy and undefined values from an object

 * @param  {object} o Object to be compacted

 * @return {object}   Compact Object

 * @link http://stackoverflow.com/a/14058408/417822

 */

_.mixin({'compactObject': function(o) {

	var clone = _.clone(o);
	_.each(clone, function(v, k) {

		if(!v) delete clone[k];

	});
	return clone;

}});

_.compactObject
/** * Toggles an array element * @param {Array} arr Source Array * @param {Mixed} val Value to toggle * @param {Boolean} Optional: Boolean to determine whether to add or remove * @return {Array} Result */ _.mixin({'arrayToggle': function(arr, val, state) { if ( _.indexOf(arr,val)==-1 || state) return _.union(arr,[val]); else return _.without(arr,val); }});

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