Add category listing endpoints for the REST API

docs/5.rest-api.md

@@ -107,6 +107,99 @@ curl https://example.com/wp-json/wp/v2/abilities
 ]
 ```
 
+## List Categories
+
+### Definition
+
+`GET /wp/v2/abilities/categories`
+
+### Arguments
+
+- `page` _(integer)_: Current page of the collection. Default: `1`.
+- `per_page` _(integer)_: Maximum number of items to return per page. Default: `50`, Maximum: `100`.
+
+### Example Request
+
+```bash
+curl -u 'USERNAME:APPLICATION_PASSWORD' \
+  https://example.com/wp-json/wp/v2/abilities/categories
+```
+
+### Example Response
+
+```json
+[
+  {
+    "slug": "data-retrieval",
+    "label": "Data Retrieval",
+    "description": "Abilities that retrieve and return data from the WordPress site.",
+    "meta": {},
+    "_links": {
+      "self": [
+        {
+          "href": "https://example.com/wp-json/wp/v2/abilities/categories/data-retrieval"
+        }
+      ],
+      "collection": [
+        {
+          "href": "https://example.com/wp-json/wp/v2/abilities/categories"
+        }
+      ],
+      "abilities": [
+        {
+          "href": "https://example.com/wp-json/wp/v2/abilities?category=data-retrieval"
+        }
+      ]
+    }
+  }
+]
+```
+
+## Retrieve a Category
+
+### Definition
+
+`GET /wp/v2/abilities/categories/{slug}`
+
+### Arguments
+
+- `slug` _(string)_: The unique slug of the category.
+
+### Example Request
+
+```bash
+curl -u 'USERNAME:APPLICATION_PASSWORD' \
+  https://example.com/wp-json/wp/v2/abilities/categories/data-retrieval
+```
+
+### Example Response
+
+```json
+{
+  "slug": "data-retrieval",
+  "label": "Data Retrieval",
+  "description": "Abilities that retrieve and return data from the WordPress site.",
+  "meta": {},
+  "_links": {
+    "self": [
+      {
+        "href": "https://example.com/wp-json/wp/v2/abilities/categories/data-retrieval"
+      }
+    ],
+    "collection": [
+      {
+        "href": "https://example.com/wp-json/wp/v2/abilities/categories"
+      }
+    ],
+    "abilities": [
+      {
+        "href": "https://example.com/wp-json/wp/v2/abilities?category=data-retrieval"
+      }
+    ]
+  }
+}
+```
+
 ## Retrieve an Ability
 
 ### Definition
@@ -247,5 +340,6 @@ The API returns standard WordPress REST API error responses with these common co
 - `ability_invalid_output` - output validation failed according to the ability's schema.
 - `ability_invalid_execute_callback` - the ability's execute callback is not callable.
 - `rest_ability_not_found` - the requested ability is not registered.
+- `rest_category_not_found` - the requested category is not registered.
 - `rest_ability_invalid_method` - the requested HTTP method is not allowed for executing the selected ability (e.g., using GET on a read-only ability, or POST on a regular ability).
 - `rest_ability_cannot_execute` - the ability cannot be executed due to insufficient permissions.

includes/rest-api/class-wp-rest-abilities-init.php

@@ -24,6 +24,10 @@ class WP_REST_Abilities_Init {
 	public static function register_routes(): void {
 		require_once __DIR__ . '/endpoints/class-wp-rest-abilities-run-controller.php';
 		require_once __DIR__ . '/endpoints/class-wp-rest-abilities-list-controller.php';
+		require_once __DIR__ . '/endpoints/class-wp-rest-abilities-categories-controller.php';
+
+		$categories_controller = new WP_REST_Abilities_Categories_Controller();
+		$categories_controller->register_routes();
 
 		$run_controller = new WP_REST_Abilities_Run_Controller();
 		$run_controller->register_routes();