insertArray.js

/**
 * Inserts an object into an array at a given index or recursively adds items if an array is given.
 * When inserting another array, passing in false for unpackArray will result in the array being inserted
 * rather than its items.
 * @param {Array} arr - The target array
 * @param {Array} item - The item being inserted
 * @param {Number} index - Where to place the item
 * @param {boolean} unpackArray - Will insert the array instead of adding its items
 */
insertArray = Utils.insertArray = function( arr, item, index, unpackArray ) {
    unpackArray = unpackArray === false ? unpackArray : true;

    if( isArray( item ) && unpackArray ) {
        for( var i=0; i<=item.length+1; i++ ){
            insertArray( arr, item.pop(), index );
        }
    }
    else if( typeof index === 'undefined ') {
        arr.push( item );
    }
    else{
        arr.splice( index, 0, item );
    }
},