Brewdog "Out of Stock" Remover - Hide all out of stock products on the Brewdog online store.

Brewdog.user.js

// ==UserScript==
// @name           Brewdog "Out of Stock" Remover
// @description    Live in blissful ignorance of the things you can't buy!
// @author         Madzen
// @include        http://www.brewdog.com/shop*
// @include        https://www.brewdog.com/shop*
// @include        http://www.brewdog.com/product*
// @include        https://www.brewdog.com/product*
// @version        1.0
// ==/UserScript==

/******************************************************************************
 * Copyright (c) 2012 Madzen
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *****************************************************************************/

/******************************************************************************
 * There is quite a mixture of activity and inactivity on the Brewdog online
 * shop from time to time, as special beers are announced, swathes of guest
 * beers are added all at once (and immediately begin to disappear almost as
 * fast as they are being posted) or as regular stock builds up and winds down.
 *
 * This script avoids some of the frustration by simply removing any options
 * from the store which are out of stock. If just some options of a product are
 * unavailable, it just removes the ones that aren't there. If all of them are
 * out, the product is removed entirely from view.
 *
 * This script will work across the main shop link, the shop sub-sections and
 * the specific product pages.
 *****************************************************************************/

var removeClassName, products, numProd;

/**
 * Determines the parent element of a particular node at a given depth.
 *
 * @param  {Object} nodeName The name of the node to determine parents for.
 * @param  {Number} depth    The depth the desired node is sitting at.
 * @return {Object}          The relevant parent node.
 */
function getParentNode(nodeName, depth) {
    var node = nodeName;
    for (var x = 0; x < depth; x++) {
        node = node.parentNode;
    }
    return node;
}

/**
 * Removes the given elements from within a wider element group.
 *
 * @param {Object} eList The wider element group to remove from.
 * @param {String} eName The name of the element class to remove.
 * @param {Number} depth The depth of the embedded element.
 */
function removeElement(eList, eName, depth) {
    var elementList = eList.getElementsByClassName(eName),
        numElements = elementList.length,
        elementNode;

    while (numElements--) {
        elementNode = getParentNode(elementList[numElements], depth);
        elementNode.style.display = 'none';
    }
}

// The format is slightly different between the product page and the main shop
// so the location needs to be checked first.
if (window.location.pathname.split('/')[1] === 'product') {
    removeClassName = 'product_versions';
}
else {
    removeClassName = 'product_listing';
}

// Grab the list of the relevant products.
products = document.getElementsByClassName(removeClassName);
numProd = products.length;

while (numProd--) {

    // Check whether the product contains any "Add to cart" options and if
    // not, all versions are out of stock, so remove the entire product.
    var regExp = /\+ Add to cart/;
    if (products[numProd].innerHTML.search(regExp) === -1) {
        products[numProd].style.display = 'none';
    }

    // If the option to add to cart was found, we need to dig a little deeper
    // and only remove the specific options that are unavailable.
    else {

        // Find any products with the out of stock span class and remove them.
        removeElement(products[numProd], 'outofstock', 2);

        // Each out of stock product has an email notifier option that needs
        // removed separately.
        removeElement(products[numProd], 'email_reminder', 1);
    }
}