Fixes #17: adds potential references limit setting

config/references.settings.json

@@ -0,0 +1,4 @@
+{
+    "_config_name": "references.settings",
+    "potential_references_limit": "25"
+  }

node_reference/node_reference.module

@@ -847,13 +847,14 @@ function _node_reference_options($field, $flat = TRUE) {
  * @codingStandardsIgnoreStart
  */
 function node_reference_potential_references($field, $options = array()) {
+  $config = config('references.settings');
   // @codingStandardsIgnoreEnd
   // Fill in default options.
   $options += array(
     'string' => '',
     'match' => 'contains',
     'ids' => array(),
-    'limit' => 25,
+    'limit' => $config->get('potential_references_limit'),
   );
 
   $results = &backdrop_static(__FUNCTION__, array());

references.info

@@ -4,6 +4,7 @@ package = Fields
 core = 7.x
 backdrop = 1.x
 type = module
+configure = admin/config/content/references
 dependencies[] = field
 dependencies[] = options
 files[] = views/references_handler_relationship.inc

references.module

@@ -232,3 +232,62 @@ function references_element_validate_integer_positive($element, &$form_state) {
     form_error($element, t('%name must be a positive integer.', array('%name' => $element['#title'])));
   }
 }
+
+/**
+ * Implements hook_config_info().
+ */
+function references_config_info() {
+  return array(
+    'references.settings' => array(
+      'label' => t('References settings'),
+      'group' => t('Configuration'),
+    ),
+  );
+}
+
+/**
+ * Implements hook_menu().
+ */
+function references_menu() {
+  $items['admin/config/content/references'] = array(
+      'title' => 'References settings',
+      'description' => 'Configure References.',
+      'page callback' => 'backdrop_get_form',
+      'page arguments' => array('references_configuration_form'),
+      'access arguments' => array('administer references'),
+  );
+
+  return $items;
+}
+
+
+/**
+ * Implements hook_permission().
+ */
+function references_permission() {
+  return array(
+    'administer references' => array(
+      'title' => t('Administer References'),
+    ),
+  );
+}
+
+/**
+ * References configuration form.
+ */
+function references_configuration_form($form, &$form_state) {
+  // Form values will be saved to this config file. See system_settings_form().
+  $form['#config'] = 'references.settings';
+
+  // Use $config->get() for default values.
+  $config = config('references.settings');
+
+  $form['potential_references_limit'] = array(
+    '#type' => 'textfield',
+    '#title' => t('Potential references limit'),
+    '#default_value' => $config->get('potential_references_limit'),
+    '#description' => t('This limit is used in various places (allowed values, autocomplete results, input validation...).'),
+  );
+
+  return system_settings_form($form);
+}

user_reference/user_reference.module

@@ -841,13 +841,14 @@ function _user_reference_options($field, $flat = TRUE) {
  * @codingStandardsIgnoreStart
  */
 function user_reference_potential_references($field, $options = array()) {
+  $config = config('references.settings');
   // @codingStandardsIgnoreEnd
   // Fill in default options.
   $options += array(
     'string' => '',
     'match' => 'contains',
     'ids' => array(),
-    'limit' => 25,
+    'limit' => $config->get('potential_references_limit'),
   );
 
   $results = &backdrop_static(__FUNCTION__, array());