Collaborative Wishlists

A wishlist in most stores is a private list of products. Here it is a collaborative, shareable object with followers, co-editors, gift purchases, and price-drop alerts — a small social layer on top of the catalog.

What a shopper can do

• Save products to one or more wishlists, with an optional target price.
• Share a wishlist publicly via a per-list token — no account needed to view it.
• Invite collaborators as editors or viewers.
• Follow someone else’s shared wishlist and get notified when they add items.
• Buy a gift from a wishlist; the purchase is hidden from the owner so the surprise holds.
• Set price alerts — get emailed when a saved item drops to a target price.

How sharing works

Sharing is implemented as a Wishlist::Sharable concern. Each wishlist carries its own share_token, and the public view is served from an unauthenticated route:

GET /shared_wishlist/:token        # public, no login required

Every other wishlist route lives inside an authenticate :user block, so the public surface is exactly one deliberate endpoint. The public page also emits Open Graph meta tags, so a shared link unfurls nicely in chat apps and social feeds.

Collaboration model

Three tables carry the social features:

Authorization for each action runs through Pundit policies, so a viewer can never mutate a list they were only invited to read.

Price alerts & re-engagement

Wishlists are also a marketing surface, driven by background jobs:

• Price alerts — wishlist_items store a target_price. When a product goes on sale, WishlistSaleNotificationJob checks watched items and emails matches, recording price_alert_notified_at so a shopper is not spammed.
• Restock alerts notify shoppers when an out-of-stock saved item returns.
• Abandoned-wishlist reminders — a daily job nudges shoppers who saved items but never came back, tracked by wishlist_last_visited_at and wishlist_reminder_sent_at.

Performance

Wishlist counts appear on every page, so they cannot trigger a query each time:

• Counter caches keep wishlist_items_count current on both User and Wishlist.
• WishlistCacheService caches rendered fragments and invalidates them per user on any change via WishlistCacheService.invalidate_for_user.
• A live count is broadcast over Turbo Streams so the header badge updates without a refresh.

Key files