wordpress-plugin-development

# WordPress Plugin Development Workflow

## Overview

Specialized workflow for creating WordPress plugins with proper architecture, hooks system, admin interfaces, REST API endpoints, and security practices. Now includes WordPress 7.0 features for modern plugin development.

## WordPress 7.0 Plugin Development

### Key Features for Plugin Developers

1. **Real-Time Collaboration (RTC) Compatibility**
   - Yjs-based CRDT for simultaneous editing
   - Custom transport via `sync.providers` filter
   - **Requirement**: Register post meta with `show_in_rest => true`

2. **AI Connector Integration**
   - Provider-agnostic AI via `wp_ai_client_prompt()`
   - Settings > Connectors admin screen
   - Works with OpenAI, Claude, Gemini, Ollama

3. **Abilities API**
   - Declare plugin capabilities for AI agents
   - REST API: `/wp-json/abilities/v1/manifest`
   - MCP adapter support

4. **DataViews & DataForm**
   - Modern admin interfaces
   - Replaces WP_List_Table patterns
   - Built-in validation

5. **PHP-Only Blocks**
   - Register blocks without JavaScript
   - Auto-generated Inspector controls

## When to Use This Workflow

Use this workflow when:
- Creating custom WordPress plugins
- Extending WordPress functionality
- Building admin interfaces
- Adding REST API endpoints
- Integrating third-party services
- Implementing WordPress 7.0 AI/Collaboration features

## Workflow Phases

### Phase 1: Plugin Setup

#### Skills to Invoke
- `app-builder` - Project scaffolding
- `backend-dev-guidelines` - Backend patterns

#### Actions
1. Create plugin directory structure
2. Set up main plugin file with header
3. Implement activation/deactivation hooks
4. Set up autoloading
5. Configure text domain

#### WordPress 7.0 Plugin Header
```php
/*
Plugin Name: My Plugin
Plugin URI: https://example.com/my-plugin
Description: A WordPress 7.0 compatible plugin with AI and RTC support
Version: 1.0.0
Requires at least: 6.0
Requires PHP: 7.4
Author: Developer Name
License: GPL2+
*/
```

#### Copy-Paste Prompts
```
Use @app-builder to scaffold a new WordPress plugin
```

### Phase 2: Plugin Architecture

#### Skills to Invoke
- `backend-dev-guidelines` - Architecture patterns

#### Actions
1. Design plugin class structure
2. Implement singleton pattern
3. Create loader class
4. Set up dependency injection
5. Configure plugin lifecycle

#### WordPress 7.0 Architecture Considerations
- Prepare for iframed editor compatibility
- Design for collaboration-aware data flows
- Consider Abilities API for AI integration

#### Copy-Paste Prompts
```
Use @backend-dev-guidelines to design plugin architecture
```

### Phase 3: Hooks Implementation

#### Skills to Invoke
- `wordpress-penetration-testing` - WordPress patterns

#### Actions
1. Register action hooks
2. Create filter hooks
3. Implement callback functions
4. Set up hook priorities
5. Add conditional hooks

#### Copy-Paste Prompts
```
Use @wordpress-penetration-testing to understand WordPress hooks
```

### Phase 4: Admin Interface

#### Skills to Invoke
- `frontend-developer` - Admin UI

#### Actions
1. Create admin menu
2. Build settings pages
3. Implement options registration
4. Add settings sections/fields
5. Create admin notices

#### WordPress 7.0 Admin Considerations
- Test with new admin color scheme
- Consider DataViews for data displays
- Implement view transitions
- Use new validation patterns

#### DataViews Example
```javascript
import { DataViews } from '@wordpress/dataviews';

const MyPluginDataView = () => {
    const data = [/* records */];
    const fields = [
        { id: 'title', label: 'Title', sortable: true },
        { id: 'status', label: 'Status', filterBy: true }
    ];
    const view = {
        type: 'table',
        perPage: 10,
        sort: { field: 'title', direction: 'asc' }
    };

    return (
        <DataViews
            data={data}
            fields={fields}
            view={view}
            onChangeView={handleViewChange}
        />
    );
};
```

#### Copy-Paste Prompts
```
Use @frontend-developer to create WordPress admin interface
```

### Phase 5: Database Operations

#### Skills to Invoke
- `database-design` - Database design
- `postgresql` - Database patterns

#### Actions
1. Create custom tables
2. Implement CRUD operations
3. Add data validation
4. Set up data sanitization
5. Create data upgrade routines

#### RTC-Compatible Post Meta
```php
// Register meta for Real-Time Collaboration
register_post_meta('post', 'my_custom_field', [
    'type' => 'string',
    'single' => true,
    'show_in_rest' => true,  // Required for RTC
    'sanitize_callback' => 'sanitize_text_field',
]);

// For WP 7.0, also consider:
register_term_meta('category', 'my_term_field', [
    'type' => 'string',
    'show_in_rest' => true,
]);
```

#### Copy-Paste Prompts
```
Use @database-design to design plugin database schema
```

### Phase 6: REST API

#### Skills to Invoke
- `api-design-principles` - API design
- `api-patterns` - API patterns

#### Actions
1. Register REST routes
2. Create endpoint callbacks
3. Implement permission callbacks
4. Add request validation
5. Document API endpoints

#### WordPress 7.0 REST API Enhancements
- Abilities API integration
- AI Connector endpoints
- Enhanced validation

#### Copy-Paste Prompts
```
Use @api-design-principles to create WordPress REST API endpoints
```

### Phase 7: Security

#### Skills to Invoke
- `wordpress-penetration-testing` - WordPress security
- `security-scanning-security-sast` - Security scanning

#### Actions
1. Implement nonce verification
2. Add capability checks
3. Sanitize all inputs
4. Escape all outputs
5. Secure database queries

#### WordPress 7.0 Security Considerations
- Test Abilities API permission boundaries
- Validate AI connector credential handling
- Review collaboration data isolation
- PHP 7.4+ requirement compliance

#### Copy-Paste Prompts
```
Use @wordpress-penetration-testing to audit plugin security
```

### Phase 8: WordPress 7.0 Features

#### Skills to Invoke
- `api-design-principles` - AI integration
- `backend-dev-guidelines` - Block development

#### AI Connector Implementation
```php
// Using WordPress 7.0 AI Connector
add_action('save_post', 'my_plugin_generate_ai_summary', 10, 2);

function my_plugin_generate_ai_summary($post_id, $post) {
    if (wp_is_post_autosave($post_id) || wp_is_post_revision($post_id)) {
        return;
    }
    
    // Check if AI client is available
    if (!function_exists('wp_ai_client_prompt')) {
        return;
    }
    
    $content = strip_tags($post->post_content);
    if (empty($content)) {
        return;
    }
    
    // Build prompt - direct string concatenation for input
    $result = wp_ai_client_prompt(
        'Create a compelling 2-sentence summary for social media: ' . substr($content, 0, 1000)
    );
    
    if (is_wp_error($result)) {
        return;
    }
    
    // Set temperature for consistent output
    $result->using_temperature(0.3);
    $summary = $result->generate_text();
    
    if ($summary && !is_wp_error($summary)) {
        update_post_meta($post_id, '_ai_summary', sanitize_textarea_field($summary));
    }
}
```

#### Abilities API Registration
```php
// Register ability categories on their own hook
add_action('wp_abilities_api_categories_init', function() {
    wp_register_ability_category('content-creation', [
        'label' => __('Content Creation', 'my-plugin'),
        'description' => __('Abilities for generating and managing content', 'my-plugin'),
    ]);
});

// Register abilities on their own hook
add_action('wp_abilities_api_init', function() {
    wp_register_ability('my-plugin/generate-summary', [
        'label' => __('Generate Summary', 'my-plugin'),
        'description' => __('Creates an AI-powered summary of content', 'my-plugin'),
        'category' => 'content-creation',
        'input_schema' => [
            'type' => 'object',
            'properties' => [
                'content' => ['type' => 'string'],
                'length' => ['type' => 'integer', 'default' => 2]
            ],
            'required' => ['content']
        ],
        'output_schema' => [
            'type' => 'object',
            'properties' => [
                'summary' => ['type' => 'string']
            ]
        ],
        'execute_callback' => 'my_plugin_generate_summary_cb',
        'permission_callback' => function() {
            return current_user_can('edit_posts');
        }
    ]);
});

// Handler callback
function my_plugin_generate_summary_cb($input) {
    $content = isset($input['content']) ? $input['content'] : '';
    $length = isset($input['length']) ? absint($input['length']) : 2;
    
    if (empty($content)) {
        return new WP_Error('empty_content', 'No content provided');
    }
    
    if (!function_exists('wp_ai_client_prompt')) {
        return new WP_Error('ai_unavailable', 'AI not available');
    }
    
    $prompt = sprintf('Create a %d-sentence summary of: %s', $length, substr($content, 0, 2000));
    
    $result = wp_ai_client_prompt($prompt)
        ->using_temperature(0.3)
        ->generate_text();
    
    if (is_wp_error($result)) {
        return $result;
    }
    
    return ['summary' => sanitize_textarea_field($result)];
}
```

#### PHP-Only Block Registration
```php
// Register block entirely in PHP (WordPress 7.0)
// Note: For full PHP-only blocks, use block.json with PHP render_callback

// First, create a block.json file in build/ or includes/blocks/
// Then register in PHP:

// Simple PHP-only block registration (WordPress 7.0+)
if (function_exists('register_block_type')) {
    register_block_type('my-plugin/featured-post', [
        'render_callback' => function($attributes, $content, $block) {
            $post_id = isset($attributes['postId']) ? absint($attributes['postId']) : 0;
            
            if (!$post_id) {
                $post_id = get_the_ID();
            }
            
            $post = get_post($post_id);
            
            if (!$post) {
                return '';
            }
            
            $title = esc_html($post->post_title);
            $excerpt = esc_html(get_the_excerpt($post));
            
            return sprintf(
                '<div class="featured-post"><h2>%s</h2><p>%s</p></div>',
                $title,
                $excerpt
            );
        },
        'attributes' => [
            'postId' => ['type' => 'integer', 'default' => 0],
            'showExcerpt' => ['type' => 'boolean', 'default' => true]
        ],
    ]);
}
```

#### Disable Collaboration (if needed)
```javascript
// Disable RTC for specific post types
import { addFilter } from '@wordpress/hooks';

addFilter(
    'sync.providers',
    'my-plugin/disable-collab',
    () => []
);
```

### Phase 9: Testing

#### Skills to Invoke
- `test-automator` - Test automation
- `php-pro` - PHP testing

#### Actions
1. Set up PHPUnit
2. Create unit tests
3. Write integration tests
4. Test with WordPress test suite
5. Configure CI

#### WordPress 7.0 Testing Priorities
- Test RTC compatibility
- Verify AI connector functionality
- Validate DataViews integration
- Test Interactivity API with watch()

#### Copy-Paste Prompts
```
Use @test-automator to set up plugin testing
```

## Plugin Structure

```
plugin-name/
├── plugin-name.php
├── includes/
│   ├── class-plugin.php
│   ├── class-loader.php
│   ├── class-activator.php
│   └── class-deactivator.php
├── admin/
│   ├── class-plugin-admin.php
│   ├── css/
│   └── js/
├── public/
│   ├── class-plugin-public.php
│   ├── css/
│   └── js/
├── blocks/           # PHP-only blocks (WP 7.0)
├── abilities/        # Abilities API
├── ai/               # AI Connector integration
├── languages/
└── vendor/
```

## WordPress 7.0 Compatibility Checklist

- [ ] PHP 7.4+ requirement documented
- [ ] Post meta registered with `show_in_rest => true` for RTC
- [ ] Meta boxes migrated to block-based UIs
- [ ] AI Connector integration tested
- [ ] Abilities API registered (if applicable)
- [ ] DataViews integration tested (if applicable)
- [ ] Interactivity API uses `watch()` not `effect`
- [ ] Tested with iframed editor
- [ ] Collaboration fallback works (post locking)

## Quality Gates

- [ ] Plugin activates without errors
- [ ] All hooks working
- [ ] Admin interface functional
- [ ] Security measures implemented
- [ ] Tests passing
- [ ] Documentation complete
- [ ] WordPress 7.0 compatibility verified

## Related Workflow Bundles

- `wordpress` - WordPress development
- `wordpress-theme-development` - Theme development
- `wordpress-woocommerce` - WooCommerce