Plugin Standard

Skill: WordPress Plugin Standard (WP.org Compliant)

This skill guides the creation of a high-quality, secure, and WordPress.org compliant plugin. It focuses on adherence to the Plugin Check (PCP) requirements and provides a robust structure including admin interfaces.

Purpose

Standardize WordPress plugin development to ensure acceptance into the official repository, maximize security, and promote maintainability through strict separation of concerns.

Required Variables

• {{plugin_name}}: Human-readable name (e.g., My Awesome Plugin).
• {{plugin_slug}}: Unique slug (e.g., my-awesome-plugin).
• {{namespace}}: PHP Namespace (e.g., PolyXGO\MyPlugin).
• {{prefix}}: Unique prefix for functions/variables (e.g., pxmp_).
• {{text_domain}}: I18n text domain (usually same as plugin slug).

Core Requirements (WordPress.org & PCP)

1. Security & Protection

• Direct Access: Use if ( ! defined( 'ABSPATH' ) ) exit; at the top of every PHP file.
• Nonces: Verify nonces for all form submissions and AJAX requests.
• Validation & Sanitization: Sanitize all inputs (sanitize_text_field, absint, etc.) and validate data before processing.
• Escaping: Escape all outputs strictly based on context (esc_html, esc_attr, wp_kses, etc.).
• Capabilities: Explicitly check user capabilities (current_user_can) for all admin actions.

2. Code Organization & Standards

• Naming: Use the {{prefix}} for all global functions, variables, and constants.
• Namespace: Use PSR-4 namespacing ({{namespace}}) to avoid class collisions.
• Separation of Concerns: Keep CSS and JS in separate files. AVOID inline styles or scripts unless dynamically generated values are required (use wp_localize_script or wp_add_inline_style only when necessary).
• No Prohibited Constructs: Never use eval(), base64_decode() for obfuscation, or short tags (<?).

3. Required Components

• Main Plugin File: Must contain the required header comment.
• readme.txt: Standard WordPress.org format.
• Admin Interface:
  • A top-level or sub-menu item for the Dashboard.
  • A dedicated Settings page for configuration.
• Uninstallation: Provide an uninstall.php file to clean up data (options, tables) when the plugin is deleted.

Implementation Steps

Step 1: Initialize Main Structure

1. Create the main plugin file {{plugin_slug}}.php with the correct header.
2. Initialize the main class with a singleton or static instance.
3. Hook into plugins_loaded to start the plugin logic.

Step 2: Register Admin Menu

1. Hook into admin_menu.
2. Add a menu page and a sub-page for Settings.
3. Enqueue admin-specific assets (CSS/JS) only on plugin pages.

Step 3: Integrate UI/UX Skill

When designing the Dashboard or Settings page:

1. Call Skill: Use (skill: ui-ux) to define the design language.
2. Apply Styles: Use the colors, typography, and spacing defined by the ui-ux skill result.
3. Write styles in assets/admin.css.

Step 4: Handle Data Persistence

1. Use the Options API (get_option, update_option) for settings.
2. Ensure all data saved to the database is sanitized.
3. Ensure all data retrieved from the database is escaped on output.

Standards and Rules

The Prefixing Rule

Every global identifier MUST start with {{prefix}}.

• ✅ {{prefix}}get_settings()
• ❌ get_settings()

The "No Inline" Rule

• CSS must be in assets/css/admin.css.
• JS must be in assets/js/admin.js.
• Use wp_enqueue_style and wp_enqueue_script correctly.

The "Smart Flush" Rule (Friendly URLs)

If the plugin uses custom post types or custom permalink structures, you MUST implement a "Queue & Flush" mechanism to update rewrite rules automatically. NEVER call flush_rewrite_rules() on every page load or init hook directly without a condition.

Implementation Pattern:

1. Queue Flush: When settings verify (e.g., via update_option hook), set a temporary flag.

   add_action('update_option_{{prefix}}permalink_settings', function($old, $new) {
       update_option('{{prefix}}flush_rewrite_flag', true);
   }, 10, 2);
   

2. Execute Flush: On the next admin_init, check and flush.

   add_action('admin_init', function() {
       if (get_option('{{prefix}}flush_rewrite_flag')) {
           flush_rewrite_rules();
           delete_option('{{prefix}}flush_rewrite_flag');
       }
   });
   

Templates

• plugin-main.php
• admin-dashboard.php
• admin-settings.php
• readme.txt
• uninstall.php
• assets/admin-css.css
• assets/admin-js.js