Frequently Bought Together for OpenCart

Overview

An Amazon-style "Frequently bought together" block for OpenCart 4. The recommendations are learned from your completed orders, so you do not build bundles by hand: the shopper sees the product plus one to three companions, ticks what they want, watches the combined price follow the ticks and adds everything with one button.

• Learned from your orders: products that were in the same order, counted from the order statuses you choose (Complete and Processing by default), within a history window, recent orders weighing more. Minimum orders and minimum confidence keep chance pairs out; very large orders are skipped
• Product page block: product images with "+", a tick box per product ("This item" first), a total that follows the ticks, Add all 3 to cart / Add both to cart, one request. Only products a shopper can buy at once are shown: enabled, in stock (or checkout of out-of-stock products allowed), priced, minimum quantity 1, no required options, no subscription plan
• Cart suggestions: "Frequently bought with items in your cart" under the cart, one-click Add to cart; the block follows the cart when it changes
• Manual control per product: pin products (shown first, in your order), exclude products or hide the block for one product
• Optional bundle discount: a percentage off one unit of each product of a set added with the block, as its own taxed Frequently bought together line in the order totals; the block shows "You save"
• Analytics: block views, add-to-cart clicks, click rate, products added, orders and revenue of the added products, a daily chart, the products whose block sells most and the strongest pairs
• Scales: the pairs are rebuilt in batches by cron (or after admin page views, or with Rebuild now), never while shoppers browse. A product page reads a few rows from an indexed table
• Safe: the add-all endpoint accepts only the product and its own recommendations that a shopper can really buy, rate-limited, the beacon needs a signed token, every shown value is escaped
• No OCMOD and no core file changes: OpenCart events, an order total extension and a daily cron entry
• OpenCart 4.1.0.x

Installation

Requirements: OpenCart 4.1.0.x, PHP 7.4 or newer with the mbstring extension.

1. In the OpenCart admin open Extensions > Installer, upload kv_frequently_bought_together.ocmod.zip and click Install.
2. Open Extensions > Extensions, choose Modules, find Frequently Bought Together, click the green Install button, then the blue pencil.
3. Installing creates the tables, registers the events and the daily cron entry, adds the Frequently bought together discount order total (status on, right after the sub-total) and builds the first set of pairs from your orders. A big order history is finished by the daily task or by Rebuild now on the Data tab.
4. The blocks are switched on after installing. Open a product page: a product that has companions in your orders (or, with the default setting, popular products of its category) shows the block.
5. Make sure the OpenCart cron job runs (php /path/to/cron.php every few minutes), or call the address shown on the Data tab.

Uninstall: Extensions > Modules > Uninstall removes the events, the cron entry and the order total line. It keeps your rules, statistics, the discounts saved with placed orders, the licence and your settings, because OpenCart 4 updates an extension by uninstalling and installing it again. To remove everything, switch on Delete all data on uninstall (Data tab), save, and then uninstall.

Update (OpenCart 4.1): Extensions > Modules > Uninstall, then Extensions > Installer: Uninstall and Delete the old entry, upload the new zip, Install, and Extensions > Modules > Install. Settings, rules, statistics, order records and the licence are restored; open the settings page once so database changes of the new version run. Installing again never resets existing settings.

Configuration

Extensions > Extensions > Modules > Frequently Bought Together (pencil). Tabs: Settings, Product rules, Data, Analytics, License.

Settings

Data (also on the Settings tab)

Product rules

Search a product, then pin products (shown first, in your order; use the arrow to move one up), exclude products (never recommended with it) or hide the block for it. The tab also shows what is computed from orders for that product right now. Pins and exclusions apply at once.

Data tab

Last build, number of pairs, Rebuild now (starts over, shows progress) and the cron address with its secret key.

License

Enter the license key from your Kavio Labs account and press Check now. A new installation works for 14 days without a key. Development hosts (localhost, *.test) work with every valid key. Without a valid license the storefront blocks are hidden and the pairs are not rebuilt; the admin pages always work, and your data stays.

Usage

The product block

On a product page that has recommendations the block appears between the buy box and the tabs (Description, Reviews, ...).

• The viewed product comes first ("This item"), followed by up to three products bought with it.
• Shoppers untick what they do not want. The total, the saving and the button follow at once: Add all 3 to cart, Add both to cart, Add selected to cart.
• One click adds the ticked products (quantity 1 each) and shows "Added 3 to your shopping cart"; the mini cart updates.
• Shown are only products that can be bought at once: enabled in this store, available, in stock (or checkout of out-of-stock products allowed), with a price, minimum quantity 1, no required option and no subscription plan. Prices follow the shopper's currency, customer group and the store's tax display. When prices are for signed-in customers only, the block is hidden for guests.

Where the products come from

1. Pinned products of this product, in your order.
2. Pairs from your orders, strongest first.
3. Popular products of the deepest category of the product, when there is not enough data (setting).

Excluded products and products of excluded categories never appear.

The cart block

Under the cart, Frequently bought with items in your cart shows up to four products bought with the cart's products (and not in the cart yet), each with Add to cart. The block reloads with the cart. Products added here belong to the set of the cart product they were recommended for, so the bundle discount applies to them too.

Bundle discount

Set Discount when bought together (%) on the Settings tab, for example 10. A set is the product of a block plus the products added with the block for it. When the cart holds that product and at least one other product of its set, one unit of each product of the set is discounted. Products added in other ways are not discounted, and a product is never discounted twice.

The discount is a normal line of the order totals ("Frequently bought together (-10%)"): the tax of the discounted amount is taken off per tax rate, the line appears in the cart, checkout, order e-mails, invoices and the order page, and it is stored with the order. When staff recalculate a placed order in the admin the discount stays, because the sets are saved with the order. Its sort order is on the Data tab of the module; the line is also listed under Extensions > Extensions > Order Totals. The block shows "You save" only while the product of the page is ticked, because that is when the cart gives the discount.

Analytics

• Block views: a block counts as seen when at least a third of it is on the screen (once per page view).
• Add-to-cart clicks, the click rate and the products added through the blocks.
• Orders and revenue of the order lines added through the blocks, in orders with the statuses that count.
• A chart per day, the products whose block sells most and the strongest pairs (orders together and confidence).

Several stores

By default all stores share the order history. Switch on Learn per store to keep the pairs per store; the block of a store then uses only that store's orders.

FAQ

How is this different from "Also bought" modules?

Most modules list the products of earlier orders. This one learns pairs with recency, minimum orders and confidence, shows them as a set with a combined price and one Add all to cart button, lets you pin and exclude products, offers an optional taxed bundle discount, suggests products in the cart and measures what the blocks sell.

My store is new. Will the block be empty?

With the default setting the block shows popular products of the same category until enough orders exist. Lower Minimum orders with both products to 1 for small stores, or pin products by hand.

How often are the recommendations updated?

Once a day by the cron entry, or after an admin page view when the data is older than Rebuild every (hours). Rebuild now on the Data tab updates them at once. Pins and exclusions apply immediately.

Does it slow down my store?

No. The heavy work runs in batches by cron or in a few seconds of an admin page view. A product page reads a few rows from an indexed table and loads up to a dozen products with the normal catalog model.

Why is a product not recommended?

It is disabled or not in this store, out of stock (and out-of-stock checkout is off), has no price, needs a minimum quantity above 1, has a required option or a subscription plan, belongs to an excluded category, is excluded for this product, or has fewer shared orders than the minimum.

Which orders count?

The order statuses chosen on the Settings tab; by default the store's Complete and Processing statuses. Orders without a status (abandoned checkouts) never count.

Can I give a discount for buying together?

Yes: set the percentage on the Settings tab (see Usage). Only products added through the block for the same product are discounted, and only while that product and another product of the set are in the cart.

Does the discount work with taxes, coupons and reward points?

The line is created by an order total extension with its own sort order (default 4, right after the coupon, before Tax), so it works next to coupons, vouchers, reward points and shipping. It never takes more than is left of the order total and of the goods, so a 100 % coupon or a points-paid order leaves it at zero. Tax is reduced per percentage tax rate by the tax of the discounted amount, exactly like the core coupon; fixed-amount taxes such as Eco Tax are not changed. Only the products the block actually showed can be added as a set (the page carries a signed list), and the saving the block shows is the saving the cart gives.

What happens if the license lapses?

The blocks are hidden and the pairs are no longer rebuilt. Carts that already hold a set keep their discount, orders keep their lines, your data and statistics stay. The admin is never blocked.

Does it work with my theme?

It targets the default OpenCart 4.1 product page and cart. The block is placed before the tab bar (or before the description tab); themes that remove both do not show the product block. The cart block is added to the cart list, which every theme that keeps OpenCart's cart controller renders.

Do the e-mails or invoices change?

No, except that the discount appears as one more total line.