41/add additional type support

headless.module

@@ -21,6 +21,12 @@ function headless_menu() {
     'access callback' => TRUE,
     'page arguments' => array(3, 4),
   );
+  // The following is for the node type where an id is not specified - to return all of the specified or a paginated subset.
+  $items['api/node/%'] = array(
+    'page callback' => 'headless_types',
+    'access callback' => TRUE,
+    'page arguments' => array(2),
+  );
   // Return JSON for individual terms.
   $items['api/%/term/%'] = array(
     'page callback' => 'headless_term_item',
@@ -133,6 +139,51 @@ function headless_type_v2($type, $nid) {
   }
 }
 
+/**
+ * Page callback for nodes type when no {$id} is specified - with or without pagination.
+ *
+ * Queries are in the format of :
+ * GET /api/node/{type}?page[number]=X&page[size]=Y
+ *                  OR
+ * GET /api/node/{type}
+ *
+ * @param string $type
+ *   A string indicating the node type to query
+ */
+function headless_types($type) {
+  $opt_page_number = NULL;
+  $opt_page_size   = NULL;
+
+  $config = config_get('headless.settings', 'node');
+  // Check if output is enabled... if not return an error.
+  if ($config[$type] != 1) {
+    $json_error = ['code' => 404];
+    backdrop_json_output($json_error);
+    backdrop_exit();
+  }
+
+  // Get any optional arguments provided -- specifically we're interested in page[number]=value and page[size]=value.
+  $opt_query_args = backdrop_get_query_parameters();
+  // Is this proper php etiquette? Can it be safely removed?
+  // furthermore, we ASSUME that both the page number AND page size will always be specified as a pair.
+  if (count($opt_query_args) > 0) {
+    $opt_page_number = $opt_query_args['page']["number"];
+    $opt_page_size   = $opt_query_args['page']['size'];
+  }
+
+  // Validate all the optional argument possibilities. If anything looks wonky, return the specified error.
+  $ret_json_err = _validate_optional_values($opt_page_size, $opt_page_number);
+  if (is_null($ret_json_err) == FALSE) {
+    backdrop_json_output($ret_json_err);
+    backdrop_exit();
+  }
+
+  // Get the items to be returned in this JSON query..
+  $nodes_to_return = _nodes_get_node_result($type, $opt_page_size, $opt_page_number);
+  backdrop_json_output($nodes_to_return);
+  backdrop_exit();
+}
+
 /**
  * Page callback for terms.
  */
@@ -301,3 +352,111 @@ function _views_get_view_result($name, $display_id = NULL, $args = NULL) {
     return array();
   }
 }
+
+/**
+ * Validate the various possible optional values if they're specified.
+ *
+ * Return the first issue found if any.
+ *
+ * @param int $opt_page_size
+ *   Specifies the optional page size for paginated queries or NULL if not desired
+ *
+ * @param int $opt_page_number
+ *   Specifies the optional page number for paginated queries or NULL if not desired
+ *
+ * @return array
+ *   An associative array identifying the JSON error to be returned
+ *   OR NULL if no error found
+ */
+function _validate_optional_values($opt_page_size, $opt_page_number) {
+  $ret_json_err = NULL;
+
+  // First check to see if neither were specified -- if so we can just return..
+  if ((is_null($opt_page_number) == TRUE) && (is_null($opt_page_size) == TRUE)) {
+    return $ret_json_err;
+  }
+
+  // Check the optional arguments to ensure both are specified and not just one.
+  if ((is_null($opt_page_number) == TRUE) && (is_null($opt_page_size) == FALSE)) {
+    // If either-or then this is considered an error and we can return one.
+    $ret_json_err = ['code' => 422,
+      'source' => "page[size] specified but NOT page[number]",
+      'title' => "Invalid optional argument",
+      'detail' => "Both Page size and Page number MUST be specified as a pair"];
+    return $ret_json_err;
+  }
+
+  if ((is_null($opt_page_number) == FALSE) && (is_null($opt_page_size) == TRUE)) {
+    // If either-or then this is considered an error and we can return one.
+    $ret_json_err = ['code' => 422,
+      'source' => "page[number] specified but NOT page[size]",
+      'title' => "Invalid optional argument",
+      'detail' => "Both Page size and Page number MUST be specified as a pair"];
+    return $ret_json_err;
+  }
+
+  // Check to see if either page number or page size = 0.  If so return an error..
+  if ($opt_page_size == 0) {
+    $ret_json_err = ['code' => 422,
+      'source' => "page[size] specified as zero",
+      'title' => "Invalid optional argument",
+      'detail' => "Page size must be >0"];
+    return $ret_json_err;
+  }
+
+  if ($opt_page_number == 0) {
+    $ret_json_err = ['code' => 422,
+      'source' => "page[number] specified as zero",
+      'title' => "Invalid optional argument",
+      'detail' => "Page number must be >0"];
+    return $ret_json_err;
+  }
+  return $ret_json_err;
+}
+
+/**
+ * Issue a query to the database to get the desired nodes for the specified type.
+ *
+ * Return the nodes matching what the user wants - pagination will be done if specified by the arguments below.
+ *
+ * @param string $type
+ *   A string specifying the node type to search for.
+ *
+ * @param int $page_size
+ *   An integer indicating the page size to use for queries using pagination. If pagination is not desired, use NULL.
+ *
+ * @param int $page_number
+ *   An integer indicating the page number to use for queries using pagination. If pagination is not desired, use NULL.
+ *
+ * @return bool|EntityInterface|null
+ *   An array of nodes matching the type specified and according to the pagination values (if provided).
+ */
+function _nodes_get_node_result($type, $page_size, $page_number) {
+  // Load the requested node and check to see if types match or not.
+  $query = new EntityFieldQuery();
+  $nodes = NULL;
+
+  // If pagination is not specified, just return the entire set of nodes..
+  if ((is_null($page_number) == TRUE) && (is_null($page_size) == TRUE)) {
+    $query->entityCondition('entity_type', 'node')
+      ->entityCondition('bundle', $type)
+      // Get only published items by checking the status.
+      ->propertyCondition('status', 1);
+  }
+  else {
+    // If we get here we're doing a paginated query.. Figure out what range we need to use.
+    $start_index = ($page_size * $page_number) - $page_size;
+    $query->entityCondition('entity_type', 'node')
+      ->entityCondition('bundle', $type)
+      // Get only published items by checking the status.
+      ->propertyCondition('status', 1)
+      ->range($start_index, $page_size);
+  }
+
+  // Do the query..
+  $result = $query->execute();
+  if (isset($result['node'])) {
+    $nodes = entity_load('node', array_keys($result['node']));
+  }
+  return ($nodes);
+}