Wiki

Registers a custom post type for managing a wiki/knowledge base and specific custom blocks & templates

link Extension name

t2/wiki

The Wiki extension (t2/wiki) provides a complete knowledge base / documentation system for WordPress. It registers a custom post type for wiki articles with hierarchical topics, search functionality, and specialized blocks for navigation and discovery.

link For End Users

link What Does This Extension Do?

The Wiki extension allows you to:

• Create structured documentation with wiki articles and hierarchical topics
• Search wiki content with a dedicated search block
• Navigate topic hierarchies with automatic topic trees
• Display related articles organized by topics
• Enable table of contents for long-form articles
• Customize article layouts with sidebar support for navigation

link Features Available

link Post Type: Wiki Article

• Custom post type for knowledge base articles
• Full block editor support for rich content
• Featured images and excerpts
• Hierarchical topic taxonomy for organization

link Taxonomy: Topics

• Hierarchical taxonomy for organizing articles
• Nested topic structure (topics and subtopics)
• Topic-based article filtering and display

link Article Features

• Table of Contents: Automatic TOC generation for articles
• Topic Tree: Sidebar navigation showing topic hierarchy
• Related Articles: Automatic article suggestions per topic

link Custom Blocks

• Wiki Search (t2/wiki-search): Dedicated search interface for wiki articles
• Wiki Topics (t2/wiki-topics): Display topic lists with article counts and navigation

link How to Use

1. Enable the Extension

   • Go to WordPress Admin → T2 Settings
   • Enable the "Wiki" extension
   • Important: Also enable dependencies:
     • t2/enable-generate-anchors (for TOC support)
     • t2/table-of-contents (for TOC block)
   • Or add to your theme's t2.json:

     {
       "mu-extensions": [
         "t2/wiki",
         "t2/enable-generate-anchors",
         "t2/table-of-contents"
       ]
     }

2. Create Topics

   • Navigate to "Wiki" → "Topics" in WordPress admin
   • Create parent topics (e.g., "Getting Started", "Advanced")
   • Create child topics under parents for nested structure
   • Topics can have descriptions and custom slugs

3. Create Wiki Articles

   • Go to "Wiki" → "All articles"
   • Click "New article"
   • Write your article content using the block editor
   • Assign one or more topics
   • Add featured image and excerpt (optional)
   • Configure article settings in the sidebar:
     • Enable/disable Table of Contents
     • Enable/disable Topic Tree in sidebar

4. Add Search to Your Site

   • Edit any page where you want wiki search
   • Add the Wiki Search block
   • Configure initial articles display:
     • Empty: Show search box only
     • Latest: Display recent articles
     • Manual: Choose specific articles to show
   • Customize search placeholder and styling

5. Display Topics

   • Add the Wiki Topics block to any page
   • Choose display mode:
     • All topics
     • Manual selection of specific topics
     • Subtopics of a parent topic
   • Configure articles per topic limit
   • Show/hide article counters

link Best Practices

• Use hierarchical topics for better organization (e.g., "API" → "Authentication", "API" → "Endpoints")
• Enable TOC for long articles to improve navigation
• Keep topic trees shallow (2-3 levels) for better UX
• Use featured images for visual consistency in search results
• Write clear excerpts that appear in search and topic listings

link For Developers

link Architecture

link File Structure

packages/extension-library/src/wiki/
├── block-library/
│   ├── wiki-search/          # Search interface block
│   │   ├── block.json
│   │   ├── block.php
│   │   ├── editor.js
│   │   ├── view.js           # Frontend search functionality
│   │   └── style.css
│   └── wiki-topics/          # Topics display block
│       ├── block.json
│       ├── block.php
│       ├── editor.js
│       └── style.css
├── inc/
│   ├── api/                  # REST API endpoints
│   ├── assets.php            # Asset enqueueing
│   ├── config.php            # Configuration helpers
│   ├── helpers.php           # Utility functions
│   ├── rest-api.php          # REST API registration
│   ├── schema.php            # Post type & taxonomy registration
│   └── templating.php        # Featured content templates
├── templates/                # PHP templates for rendering
├── src/                      # Source files (if applicable)
├── extension.json            # Extension metadata
├── extension.php             # Entry point
├── constants.js              # JS constants
├── index.js                  # Frontend JS initialization
├── view.js                   # Frontend interactions
├── style.css                 # Frontend styles
├── style-sidebar.css         # Sidebar-specific styles
└── props.css                 # Additional property styles

link Key Components

REST API (inc/rest-api.php, inc/api/)

• Custom endpoints for wiki-specific queries
• Search functionality
• Topic tree data
• Article filtering by topics

Schema Registration (inc/schema.php)

• Wiki post type registration
• Topic taxonomy registration
• Post meta registration (TOC, topic tree toggles)
• Transient caching for topic trees

Templating (inc/templating.php, templates/)

• Featured Content card templates
• Custom rendering for wiki articles

link Configuration Options

Configure via t2.json in your theme root:

{
  "version": 1,
  "mu-extensions": [
    "t2/wiki",
    "t2/enable-generate-anchors",
    "t2/table-of-contents"
  ],
  "t2/wiki": {
    "postTypeKey": "wiki",
    "taxonomyTopicKey": "topic",
    "features": {
      "toc": true,
      "topicTree": true
    }
  }
}

link Configuration Reference

link Post Meta Keys

The extension registers the following post meta fields:

• enable_toc (boolean, default: true): Whether to display table of contents for this article
• enable_topic_tree (boolean, default: true): Whether to display topic tree sidebar for this article

Both fields are:

• Exposed via REST API (show_in_rest: true)
• Available in the block editor sidebar
• Accessible on the post object after the_post hook

link Enhanced WP_Post Object

The wiki extension enhances WP_Post objects with additional properties:

// After the_post() hook, wiki posts have:
$post->display_toc        // boolean: TOC enabled?
$post->display_topic_tree // boolean: Topic tree enabled?

This allows easy access in templates:

if ( $post->display_topic_tree ) {
    // Render topic tree sidebar
}

link Topic Tree System

Caching Strategy

• Topic trees are cached in transients (1 hour TTL)
• Cache invalidated on topic create/update/delete
• Two cache variants: with and without empty topics

Helper Functions (inc/schema.php)

// Get the full topic tree
$tree = \T2\Extensions\Library\Wiki\Schema\get_topic_tree(
    $with_empty_topics = false,
    $no_cache = false
);

// Each tree item contains:
// - term_id, name, slug, description, count
// - children (array of child topic items)

link REST API

The extension provides custom REST API endpoints under t2/wiki/v1 namespace:

Constants

T2_EXTENSIONS_WIKI_REST_API_PREFIX = 't2/wiki/v1'

See inc/rest-api.php and inc/api/ for endpoint implementations.

link Block: Wiki Search

Block Name: t2/wiki-search

Attributes:

{
  "initialArticlesList": "empty|latest|manual",
  "maxNumberOfInitialArticles": 9,
  "manualArticles": [],
  "displayInitialArticlesTitle": true,
  "initialArticlesTitle": "Latest articles"
}

Frontend Behavior (view.js):

• Real-time search using REST API
• Debounced search input
• Results rendered with JS
• Accessible keyboard navigation

link Block: Wiki Topics

Block Name: t2/wiki-topics

Attributes:

{
  "selection": "all|manual|subtopics",
  "manualTopics": [],
  "subtopicsOf": 0,
  "articlesPerTopic": 10,
  "maxNumberOfTopics": 50,
  "hideArticlesCounter": false,
  "showSubtopicsOnly": false
}

Rendering:

• Server-side rendering in PHP
• Displays topic hierarchies with article lists
• Shows article counts per topic
• Supports nested topic display

link Helper Functions

get_wiki_post_type() (inc/config.php)
Returns the configured wiki post type key:

use function T2\Extensions\Library\Wiki\Config\get_wiki_post_type;

$post_type = get_wiki_post_type(); // 'wiki' by default

get_topic_taxonomy() (inc/config.php)
Returns the configured topic taxonomy key:

use function T2\Extensions\Library\Wiki\Config\get_topic_taxonomy;

$taxonomy = get_topic_taxonomy(); // 'topic' by default

get_taxonomy_terms_tree() (inc/helpers.php)
Build a hierarchical tree of taxonomy terms:

use function T2\Extensions\Library\Wiki\Helpers\get_taxonomy_terms_tree;

$tree = get_taxonomy_terms_tree(
    $taxonomy = 'topic',
    $parent_id = 0,
    $with_empty = false
);

link Featured Content Integration

The wiki extension automatically registers a card template for Featured Content Layout block:

register_featured_content_template(
    "post-type-{$wiki_post_type}",
    get_wiki_card_template()
);

This provides styled cards when displaying wiki articles in Featured Content blocks.

link Extension Dependencies

Required Extensions (must be enabled):

• t2/enable-generate-anchors: Generates anchor IDs for headings (required for TOC)
• t2/table-of-contents: Provides TOC block functionality

These dependencies are declared in extension.json:

{
  "extensionDependencies": [
    "t2/enable-generate-anchors",
    "t2/table-of-contents"
  ]
}

link Constants Defined

T2_EXTENSIONS_WIKI_PATH               // Path to wiki extension directory
T2_EXTENSIONS_WIKI_TEMPLATES_PATH     // Path to templates subdirectory
T2_EXTENSIONS_WIKI_REST_API_PREFIX    // REST API namespace (t2/wiki/v1)

link Development Tips

1. Build required for JS changes: Run npm run build after editing view.js or editor files
2. Transient cache: Clear transients during development: wp transient delete --all
3. REST API testing: Use wp-json/t2/wiki/v1/ endpoints for API testing
4. Topic tree performance: Large topic hierarchies benefit from caching; monitor transient usage
5. Search customization: Modify view.js for frontend search behavior

link Hooks & Actions

Actions

init - Registers post type, taxonomies, and meta fields
the_post - Enhances WP_Post objects with wiki-specific properties
created_{$topic_taxonomy} - Clears topic tree cache
edited_{$topic_taxonomy} - Clears topic tree cache
delete_{$topic_taxonomy} - Clears topic tree cache

link Common Use Cases

Custom Search Results Template
Modify the search results rendering by editing templates in templates/ directory.

Add Custom Post Meta

add_action( 'init', function() {
    register_post_meta( 'wiki', 'custom_field', [
        'type'         => 'string',
        'single'       => true,
        'show_in_rest' => true,
    ] );
}, 11 ); // After wiki registers its post type

Customize Topic Display
Filter topic queries before rendering in the Wiki Topics block.

Extend REST API
Add custom endpoints under T2_EXTENSIONS_WIKI_REST_API_PREFIX namespace:

add_action( 'rest_api_init', function() {
    register_rest_route( T2_EXTENSIONS_WIKI_REST_API_PREFIX, '/custom-endpoint', [
        'methods'  => 'GET',
        'callback' => 'your_callback_function',
    ] );
} );

link Known Limitations

• Search is client-side only (no server-side fallback)
• Topic tree depth is not limited programmatically (UX recommendation: 3 levels max)
• TOC requires Generate Anchors extension to be enabled
• No built-in article versioning or revision comparison