Lesson 96 – Implementation: Complete My Watchlist Frontend Integration

Team Wpnzee on July 12, 2026

Overview

In this lesson, we completed the implementation of the My Watchlist feature for the Flipnzee Auctions plugin. The feature now provides logged-in users with a dedicated page to view and manage all auctions they have saved.

Unlike previous lessons that focused on the AJAX add/remove functionality, this implementation connects the entire workflow—from the watchlist database table to the auction and listing information displayed on the frontend.

Objectives

The objectives of this lesson were to:

Retrieve the logged-in user’s watchlist.
Load the corresponding auction records.
Retrieve the associated WordPress listing posts.
Display auction information in a user-friendly layout.
Provide direct links back to each listing.
Synchronize the Add/Remove Watchlist button state.
Eliminate debugging code and prepare the feature for production.

Watchlist Retrieval

The shortcode begins by confirming that the visitor is logged in.

if ( ! is_user_logged_in() ) {
    return '<p>Please log in to view your Watchlist.</p>';
}

After authentication, the current user’s ID is obtained.

$user_id = get_current_user_id();

The watchlist entries are then retrieved using the Watchlist Manager.

$watchlist = Flipnzee_Watchlist_Manager::get_user_watchlist(
    $user_id
);

Auction Lookup

Each watchlist record stores an auction_id.

For every saved item, the shortcode retrieves the corresponding auction.

$auction = Flipnzee_Auction_Manager::get_auction(
    $item['auction_id']
);

Invalid auctions are skipped automatically.

if ( ! $auction ) {
    continue;
}

Listing Retrieval

Every auction references its associated WordPress listing.

$listing = get_post(
    $auction->listing_id
);

If a listing has been deleted or is unavailable, it is skipped gracefully.

if ( ! $listing ) {
    continue;
}

Displaying Auction Information

Each watchlist item now displays:

Listing title
Auction status
Current bid
Auction ending date
View Listing button
Watchlist button

Example:

<h3><?php echo esc_html( get_the_title( $listing ) ); ?></h3>

Current bid:

<?php echo esc_html(
    number_format_i18n(
        $auction->current_bid,
        2
    )
); ?>

Auction end date:

mysql2date(
    'F j, Y g:i A',
    $auction->auction_end
);

Watchlist Button Synchronization

One of the final bugs discovered during development involved the Watchlist button displaying “Add to Watchlist” even when an auction already existed inside the user’s watchlist.

This issue was traced to the button state logic and corrected so that the frontend accurately reflects whether an auction is already saved.

Users now immediately see the correct button state without inconsistent behaviour.

Frontend Result

Each watchlist item is rendered in a clean card layout containing:

Website title
Auction status
Current bid
Auction end time
View Listing button
Remove from Watchlist button

This provides buyers with a convenient dashboard for tracking auctions they intend to follow.

Debugging Process

This lesson involved extensive debugging and verification.

During development we verified:

Watchlist database records
Auction retrieval
Listing retrieval
WordPress post loading
Auction-to-listing relationships
Shortcode rendering
Frontend output

Temporary debugging statements such as:

var_dump()
print_r()
<pre>
diagnostic echo statements

were removed after successful verification.

WordPress Coding Standards

Throughout the implementation we continued following WordPress coding standards by:

Escaping all frontend output.
Sanitizing user input.
Using prepared database queries.
Separating business logic into manager classes.
Keeping shortcode rendering focused on presentation.

Testing Completed

The completed feature has been tested for:

Logged-in users
Empty watchlists
Multiple watchlist items
Invalid auctions
Missing listings
Add to Watchlist
Remove from Watchlist
AJAX updates
Frontend rendering
Button state synchronization

Files Updated

Primary files updated during this lesson include:

includes/class-shortcodes.php
includes/class-watchlist-manager.php
includes/class-watchlist-ajax.php
assets/js/watchlist.js

Download Source Code

Download the starting version of the plugin before the lesson:

⬇ Download Plugin (After Lesson 95) (59 downloads )

Download the completed version after this lesson:

⬇ Download Plugin (After Lesson 96) (29 downloads )

Outcome

Lesson 96 completes the My Watchlist feature for Flipnzee Auctions.

Users can now save auctions, revisit them later, monitor their progress, and quickly navigate back to the corresponding listing page. This feature significantly improves buyer engagement and lays the foundation for future buyer dashboard functionality.

Git Commit

Lesson 96: Complete My Watchlist frontend integration and production-ready Watchlist system

This marks another major milestone in the Flipnzee Auctions plugin roadmap, with the buyer-facing Watchlist feature now fully functional and ready for production use.

Category: Flipnzee Auctions – Design & Planning