validate request and return 404 when exposer dsnt suppor mapper

src/api/endpoints/class-tainacan-rest-items-controller.php

@@ -240,6 +240,16 @@ class REST_Items_Controller extends REST_Controller {
 		
 		$args = $this->prepare_filters($request);
 
+		/**
+		 * allow plugins to hijack the process.
+		 * 
+		 * If it returns a \WP_REST_Response, the method will return it and ignore the rest of the script
+		 */
+		$alternate_response = apply_filters('tainacan-api-get-items-alternate', false, $request);
+		if ( $alternate_response instanceof \WP_REST_Response ) {
+			return $alternate_response;
+		}
+		
 		$collection_id = [];
 		if($request['collection_id']) {
 			$collection_id = $request['collection_id'];

src/api/endpoints/class-tainacan-rest-metadatum-mappers-controller.php

@@ -101,7 +101,7 @@ class REST_Metadatum_Mappers_Controller extends REST_Controller {
 	           array_key_exists('metadata_mappers', $body) &&
 	           is_array($body['metadata_mappers']) &&
 	           count($body['metadata_mappers']) > 0 &&
-	           \Tainacan\Mappers_Handler::request_has_mapper($request)
+	           \Tainacan\Mappers_Handler::get_mapper_from_request($request)
 	    ) {
 	        $metadatum_mapper = $body['metadata_mappers'][0];
 	        $metadatum = \Tainacan\Repositories\Repository::get_entity_by_post($metadatum_mapper['metadatum_id']);
@@ -121,7 +121,7 @@ class REST_Metadatum_Mappers_Controller extends REST_Controller {
 	    $Tainacan_Mappers = \Tainacan\Mappers_Handler::get_instance();
 	    $Tainacan_Metadata = \Tainacan\Repositories\Metadata::get_instance();
 	    $body = json_decode( $request->get_body(), true );
-	    if($mapper = $Tainacan_Mappers::request_has_mapper($request)) {
+	    if($mapper = $Tainacan_Mappers::get_mapper_from_request($request)) {
 	        if(count($body['metadata_mappers']) > 0) {
 	            $response = [];
 	            $saved = [];

src/exposers/class-tainacan-exposer.php

@@ -80,6 +80,7 @@ abstract class Exposer {
 	
 	/**
 	 * Return list of supported mappers for this type 
+	 * @return array List of mappers
 	 */
 	public function get_mappers() {
 		$mappers = apply_filters('tainacan-exporser-type-mappers', $this->mappers, $this);
@@ -90,7 +91,7 @@ abstract class Exposer {
 		} elseif (is_array($mappers)) {
 			return $mappers;
 		}
-		return null;
+		return [];
 	}
 
 }

src/exposers/class-tainacan-exposers-handler.php

@@ -1,6 +1,7 @@
 <?php
 namespace Tainacan;
 
+use Tainacan\Mappers_Hanlder;
 use Tainacan\Mappers\Mapper;
 
 defined( 'ABSPATH' ) or die( 'No script kiddies please!' );
@@ -37,6 +38,8 @@ class Exposers_Handler {
 		do_action('tainacan-register-exposer', $this);
 		
 		add_filter( 'rest_request_after_callbacks', [$this, 'rest_request_after_callbacks'], 10, 3 ); //exposer types
+
+		add_filter( 'tainacan-api-get-items-alternate', [$this, 'filter_check_items_request'], 10, 2 );
 		
 	}
 	
@@ -205,8 +208,65 @@ class Exposers_Handler {
 	    }
 	    return $ret;
 	}
-	
-	
+
+	/**
+	 * Filters Items request
+	 * and checks if current exposer (if any) supports this mapper.
+	 * 
+	 * If it does not, return 404
+	 */
+	public function filter_check_items_request($response, $request) {
+		$exposer = $this->request_has_exposer($request);
+		$mapper = Mappers_Handler::get_instance()->get_mapper_from_request($request);
+		if ( false === $exposer ) {
+			return $response;
+		}
+
+		$accpeted_mappers = $exposer->get_mappers();
+
+		if ( $exposer->accept_no_mapper ) {
+			// translators: To be displayed in a list of supported mappers of a exposer. Example: Supported mappers: No mapper, Dublin Core
+			array_unshift($accpeted_mappers, __('No mapper', 'tainacan'));
+		}
+
+		$accpeted_mappers_string = implode(', ', $accpeted_mappers);
+
+		$return404 = false;
+
+		if ( $mapper == false ) {
+			
+			if ( $exposer->accept_no_mapper ) {
+				return $response;
+			} else {
+				$return404 = true;
+				// translators: 1: Exposer name, 2: List of accepted mappers. example: CSV exposer requires one of the following mappers: dublin-core, other-mapper
+				$error_message = sprintf( __('%1$s exposer requires one of the following mappers: %2$s', 'tainacan'), $exposer->get_name(), $accpeted_mappers_string);
+			}
+		} else {
+			
+			if ( in_array($mapper->slug, $accpeted_mappers) ) {
+				return $response;
+			} else {
+				$return404 = true;
+				// translators: 1: Exposer name. 2: List of accpeted mappers. example: CSV exposer does not support current mapper. Supported mappers are: dublin-core, other-mapper
+				$error_message = sprintf( __('%1$s exposer does not support current mapper. Supported mappers are: %2$s', 'tainacan'), $exposer->get_name(), $accpeted_mappers_string);
+			}
+
+		}
+		
+		if ( $return404 ) {
+			$response = new \WP_REST_Response([
+				'error_message' => $error_message,
+			], 404);
+			remove_filter( 'rest_request_after_callbacks', [$this, 'rest_request_after_callbacks']);
+		}
+
+		return $response;
+
+
+
+	}
+
 	
 	/**
 	 * 

src/exposers/class-tainacan-html.php

@@ -10,6 +10,8 @@ class Html extends Exposer {
 	
 	public $slug = 'html'; // type slug for url safe
 	public $name = 'HyperText Markup Language';
+	protected $mappers = true;
+	public $accept_no_mapper = true;
 	
 	function __construct() {
 		$this->set_name( 'HTML' );

src/exposers/class-tainacan-json-ld.php

@@ -24,7 +24,7 @@ class JSON_LD extends Exposer {
 		    'Content-Type: application/json; charset=' . get_option( 'blog_charset' ),
 		    'Link: <'.get_bloginfo('url').'/item.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"'
 		]);
-		$mapper = \Tainacan\Exposers_Handler::request_has_mapper($request);
+		$mapper = \Tainacan\Exposers_Handler::get_mapper_from_request($request);
 		if(property_exists($mapper, 'XML_namespace') && !empty($mapper->XML_namespace)) {
 		    $namespace = $mapper->XML_namespace;
 		    $context_slug = str_replace(':', '', $mapper->prefix);

src/exposers/class-tainacan-xml.php

@@ -23,7 +23,7 @@ class Xml extends Exposer {
 	 */
 	public function rest_request_after_callbacks( $response, $handler, $request ) {
 		$response->set_headers( ['Content-Type: application/xml; charset=' . get_option( 'blog_charset' )] );
-		$mapper = \Tainacan\Exposers_Handler::request_has_mapper($request);
+		$mapper = \Tainacan\Exposers_Handler::get_mapper_from_request($request);
 		$xml = new \SimpleXMLElement( '<?xml version="1.0"?><data></data>' );
 		$namespace = null;
 		$xml_root = $xml;

src/mappers/class-tainacan-mappers-handler.php

@@ -23,7 +23,7 @@ class Mappers_Handler {
 	    self::$instance = $this;
 
 		$this->register_mapper('Tainacan\Mappers\Dublin_Core');
-		//$this->register_mapper('Tainacan\Mappers\Value');
+		
 		do_action('tainacan-register-mappers', $this);
 		
 		add_filter( 'tainacan-admin-i18n', [$this, 'mappers_i18n']);
@@ -110,25 +110,27 @@ class Mappers_Handler {
 	 * @param \WP_REST_Request $request
 	 * @return Mappers\Mapper|boolean false
 	 */
-	public static function request_has_mapper($request) {
+	public static function get_mapper_from_request($request) {
 		$body = json_decode( $request->get_body(), true );
 		$Tainacan_Mappers = self::get_instance();
 		$query_url_params = $request->get_query_params();
 		
+		$return_mapper = false;
+
 		if( // There is a defined mapper
 			is_array($body) && array_key_exists(self::MAPPER_PARAM, $body) &&
 			$Tainacan_Mappers->mapper_exists($body[self::MAPPER_PARAM])
 		) {
 			$mapper = $Tainacan_Mappers->check_class_name($body[self::MAPPER_PARAM], true, self::MAPPER_CLASS_PREFIX);
-			return new $mapper;
+			$return_mapper = new $mapper;
 		} elseif(
 		    is_array($query_url_params) && array_key_exists(self::MAPPER_PARAM, $query_url_params) &&
 		    $Tainacan_Mappers->mapper_exists($query_url_params[self::MAPPER_PARAM])
 		) {
 			$mapper = $Tainacan_Mappers->check_class_name($query_url_params[self::MAPPER_PARAM], true, self::MAPPER_CLASS_PREFIX);
-			return new $mapper;
+			$return_mapper = new $mapper;
 		} 
-		return false; // No mapper need, using Tainacan defautls
+		return apply_filters('tainacan-get-mapper-from-request', $return_mapper, $request); 
 	}
 	
 	/**
@@ -224,7 +226,7 @@ class Mappers_Handler {
 	public function create_mapped_collection( $collection, $request ) {
 	    
 		
-		if ($mapper = $this->request_has_mapper($request)) {
+		if ($mapper = $this->get_mapper_from_request($request)) {
 			
 			$mapper_metadata = $mapper->metadata;
 			if(is_array($mapper_metadata) ) {
@@ -276,7 +278,7 @@ class Mappers_Handler {
 	
 	function filter_item_api_response($item_arr, $item, $request) {
 		
-		$mapper = $this->request_has_mapper($request);
+		$mapper = $this->get_mapper_from_request($request);
 		
 		if (!$mapper) {
 			return $item_arr;

src/mappers/class-tainacan-value.php

@@ -1,18 +0,0 @@
-<?php
-
-namespace Tainacan\Mappers;
-
-/**
- *  Mapper class for export metadata in key => value format where key can be defined
- *
- */
-class Value extends Mapper {
-	public $slug = 'value';
-	public $name = 'Value';
-	public $allow_extra_metadata = true;
-	public $context_url = '';
-	public $header = '';
-	public $metadata = false;
-	public $show_ui = false;
-	
-}