feat(content-distribution): reserved taxonomies

includes/class-content-distribution.php

@@ -248,6 +248,24 @@ public static function get_reserved_post_meta_keys() {
 		);
 	}
 
+	/**
+	 * Get taxonomies that should not be distributed.
+	 *
+	 * @return string[] The reserved taxonomies.
+	 */
+	public static function get_reserved_taxonomies() {
+		$reserved_taxonomies = [
+			'author', // Co-Authors Plus 'author' taxonomy should be ignored as it requires custom handling.
+		];
+
+		/**
+		 * Filters the reserved taxonomies that should not be distributed.
+		 *
+		 * @param string[] $reserved_taxonomies The reserved taxonomies.
+		 */
+		return apply_filters( 'newspack_network_content_distribution_reserved_taxonomies', $reserved_taxonomies );
+	}
+
 	/**
 	 * Whether a given post is distributed.
 	 *

includes/content-distribution/class-incoming-post.php

@@ -288,16 +288,20 @@ protected function upload_thumbnail() {
 	 * @return void
 	 */
 	protected function update_taxonomy_terms() {
-		$data = $this->payload['post_data']['taxonomy'];
+		$reserved_taxonomies = Content_Distribution::get_reserved_taxonomies();
+		$data                = $this->payload['post_data']['taxonomy'];
 		foreach ( $data as $taxonomy => $terms ) {
+			if ( in_array( $taxonomy, $reserved_taxonomies, true ) ) {
+				continue;
+			}
 			if ( ! taxonomy_exists( $taxonomy ) ) {
 				continue;
 			}
 			$term_ids = [];
 			foreach ( $terms as $term_data ) {
-				$term = get_term_by( 'slug', $term_data['slug'], $taxonomy, ARRAY_A );
+				$term = get_term_by( 'name', $term_data['name'], $taxonomy, ARRAY_A );
 				if ( ! $term ) {
-					$term = wp_insert_term( $term_data['name'], $taxonomy, [ 'slug' => $term_data['slug'] ] );
+					$term = wp_insert_term( $term_data['name'], $taxonomy );
 					if ( is_wp_error( $term ) ) {
 						continue;
 					}

includes/content-distribution/class-outgoing-post.php

@@ -215,9 +215,13 @@ protected function get_processed_post_content() {
 	 * @return array The taxonomy term data.
 	 */
 	protected function get_post_taxonomy_terms() {
-		$taxonomies = get_object_taxonomies( $this->post->post_type, 'objects' );
-		$data       = [];
+		$reserved_taxonomies = Content_Distribution::get_reserved_taxonomies();
+		$taxonomies          = get_object_taxonomies( $this->post->post_type, 'objects' );
+		$data                = [];
 		foreach ( $taxonomies as $taxonomy ) {
+			if ( in_array( $taxonomy->name, $reserved_taxonomies, true ) ) {
+				continue;
+			}
 			if ( ! $taxonomy->public ) {
 				continue;
 			}

tests/unit-tests/test-incoming-post.php

@@ -330,4 +330,29 @@ public function test_post_meta_sync() {
 		// Assert that the custom post meta was removed on relink.
 		$this->assertEmpty( get_post_meta( $post_id, 'custom', true ) );
 	}
+
+	/**
+	 * Test reserved taxonomies.
+	 */
+	public function test_reserved_taxonomies() {
+		$payload = $this->get_sample_payload();
+		$taxonomy = 'author';
+
+		// Register a reserved taxonomy.
+		register_taxonomy( $taxonomy, 'post', [ 'public' => true ] );
+
+		$payload['post_data']['taxonomy']['author'] = [
+			[
+				'name' => 'Author 1',
+				'slug' => 'author-1',
+			],
+		];
+
+		// Insert the linked post.
+		$post_id = $this->incoming_post->insert( $payload );
+
+		// Assert that the post does not have the reserved taxonomy term.
+		$terms = wp_get_post_terms( $post_id, $taxonomy );
+		$this->assertEmpty( $terms );
+	}
 }

tests/unit-tests/test-outgoing-post.php

@@ -166,4 +166,19 @@ public function test_post_meta() {
 		$this->assertSame( 'a', $payload['post_data']['post_meta'][ $multiple_meta_key ][0] );
 		$this->assertSame( 'b', $payload['post_data']['post_meta'][ $multiple_meta_key ][1] );
 	}
+
+	/**
+	 * Test reserved taxonomies.
+	 */
+	public function test_reserved_taxonomies() {
+		$post = $this->outgoing_post->get_post();
+		$taxonomy = 'author';
+		register_taxonomy( $taxonomy, 'post', [ 'public' => true ] );
+
+		$term = $this->factory->term->create( [ 'taxonomy' => $taxonomy ] );
+		wp_set_post_terms( $post->ID, [ $term ], $taxonomy );
+
+		$payload = $this->outgoing_post->get_payload();
+		$this->assertTrue( empty( $payload['post_data']['taxonomy'][ $taxonomy ] ) );
+	}
 }