[Block Library - Post Terms]: Add dynamic variations of custom taxonomies

docs/reference-guides/core-blocks.md

@@ -71,7 +71,7 @@ A calendar of your site’s posts. ([Source](https://github.com/WordPress/gutenb
 -	**Supports:** align
 -	**Attributes:** month, year
 
-## Categories
+## Categories List
 
 Display a list of all categories. ([Source](https://github.com/WordPress/gutenberg/tree/trunk/packages/block-library/src/categories))
 

packages/block-library/package.json

@@ -29,7 +29,8 @@
 		"src/**/*.scss",
 		"src/navigation-link/index.js",
 		"src/template-part/index.js",
-		"src/query/index.js"
+		"src/query/index.js",
+		"src/post-terms/index.js"
 	],
 	"dependencies": {
 		"@babel/runtime": "^7.16.0",

packages/block-library/src/categories/block.json

@@ -2,7 +2,7 @@
 	"$schema": "https://schemas.wp.org/trunk/block.json",
 	"apiVersion": 2,
 	"name": "core/categories",
-	"title": "Categories",
+	"title": "Categories List",
 	"category": "widgets",
 	"description": "Display a list of all categories.",
 	"textdomain": "default",

packages/block-library/src/post-terms/hooks.js

@@ -0,0 +1,27 @@
+/**
+ * WordPress dependencies
+ */
+import { postCategories, postTerms } from '@wordpress/icons';
+
+const variationIconMap = {
+	category: postCategories,
+	post_tag: postTerms,
+};
+
+// We add `icons` to categories and tags. The remaining ones use
+// the block's default icon.
+export default function enhanceVariations( settings, name ) {
+	if ( name !== 'core/post-terms' ) {
+		return settings;
+	}
+	const variations = settings.variations.map( ( variation ) => ( {
+		...variation,
+		...( variationIconMap[ variation.name ] && {
+			icon: variationIconMap[ variation.name ],
+		} ),
+	} ) );
+	return {
+		...settings,
+		variations,
+	};
+}

packages/block-library/src/post-terms/index.js

@@ -1,20 +1,27 @@
 /**
- * Internal dependencies
+ * WordPress dependencies
  */
-import metadata from './block.json';
-import edit from './edit';
-import variations from './variations';
+import { postCategories as icon } from '@wordpress/icons';
+import { addFilter } from '@wordpress/hooks';
 
 /**
- * WordPress dependencies
+ * Internal dependencies
  */
-import { postTerms as icon } from '@wordpress/icons';
+import metadata from './block.json';
+import edit from './edit';
+import enhanceVariations from './hooks';
 
 const { name } = metadata;
 export { metadata, name };
 
 export const settings = {
 	icon,
-	variations,
 	edit,
 };
+
+// Importing this file includes side effects. This is whitelisted in block-library/package.json under sideEffects
+addFilter(
+	'blocks.registerBlockType',
+	'core/template-part',
+	enhanceVariations
+);

packages/block-library/src/post-terms/index.php

@@ -59,10 +59,48 @@ function render_block_core_post_terms( $attributes, $content, $block ) {
  * Registers the `core/post-terms` block on the server.
  */
 function register_block_core_post_terms() {
+	$taxonomies = get_taxonomies(
+		array(
+			'public'       => true,
+			'show_in_rest' => true,
+		),
+		'objects'
+	);
+
+	// Split the available taxonomies to `built_in` and custom ones,
+	// in order to prioritize the `built_in` taxonomies at the
+	// search results.
+	$built_ins         = array();
+	$custom_variations = array();
+
+	// Create and register the eligible taxonomies variations.
+	foreach ( $taxonomies as $taxonomy ) {
+		$variation = array(
+			'name'        => $taxonomy->name,
+			'title'       => $taxonomy->label,
+			/* translators: %s: taxonomy's label */
+			'description' => sprintf( __( 'Display the assigned taxonomy: %s' ), $taxonomy->label ),
+			'attributes'  => array(
+				'term' => $taxonomy->name,
+			),
+			'isActive'    => array( 'term' ),
+		);
+		// Set the category variation as the default one.
+		if ( 'category' === $taxonomy->name ) {
+			$variation['isDefault'] = true;
+		}
+		if ( $taxonomy->_builtin ) {
+			$built_ins[] = $variation;
+		} else {
+			$custom_variations[] = $variation;
+		}
+	}
+
 	register_block_type_from_metadata(
 		__DIR__ . '/post-terms',
 		array(
 			'render_callback' => 'render_block_core_post_terms',
+			'variations'      => array_merge( $built_ins, $custom_variations ),
 		)
 	);
 }