Overview

This WordPress plugin allows users to subscribe to specific products and receive email notifications when the product is updated in terms of stock or new release. It supports both English and Finnish languages and provides options for subscription confirmation, un-subscription, and email notifications.

Features

• Product Subscription: Users can subscribe to individual products using their email.
• Email Notifications: Subscribers receive an email when the product is updated.
• Subscription Confirmation: Users must confirm their subscription via email before being added.
• Unsubscription Link: Each email contains an unsubscribe link.
• Multilingual Support: Works with English and Finnish (en, fi).
• Admin Management: Subscribed users are stored in the WordPress database.

Installation

1. Upload the Plugin
   • Go to Plugins > Add New in your WordPress dashboard.
   • Click Upload Plugin and select the plugin ZIP file.
   • Click Install Now and activate the plugin.
2. Settings
   • No separate settings page; the plugin works automatically when users subscribe to products.

How It Works

1. Subscribing to a Post

• A user enters their email in the subscription form on a post page.
• The plugin sends a confirmation email to verify the subscription.
• If the user clicks the confirmation link, their email is stored in the WordPress database.

2. Sending Update Notifications

• When an admin updates a product or getting updated via Product API, the plugin checks for subscribed users.
• An email is sent to each subscriber, informing them about the update.
• The email includes a link to view the updated post.

3. Unsubscribing

• Each email contains an unsubscribe link.
• Clicking the link removes the user from the subscriber list for that product.

Technical Details

Database Storage

• Subscriber data is stored in wp_options under the key subscribed_users.

Email Handling

• Emails are sent using wp_mail().
• Templates are language-dependent (en, fi).

Security & Performance

• Uses sanitize_text_field() and sanitize_email() to prevent SQL injection.
• Ensures users confirm subscriptions before storing their email.
• Implements caching (transients) for improved performance.