diff --git a/serial.inc b/serial.inc
index cb3dec2..15eeb92 100644
--- a/serial.inc
+++ b/serial.inc
@@ -1,5 +1,4 @@
 <?php
-
 /**
  * @file
  * Internal functions for the Serial module.
@@ -16,94 +15,93 @@
 /**
  * Creates an assistant serial table for a new created field.
  *
- * @param $field
+ * @param array $field
  *   a serial field
- * @param $instance
+ * @param array $instance
  *   a new instance of that serial field
  */
-function _serial_create_table($field, $instance) {
-  $table = _serial_get_field_table_name($field, $instance);
-  $schema = _serial_get_table_schema();
-  db_create_table($table, $schema);
+function _serial_create_table(array $field, array $instance) {
+  db_create_table(
+    _serial_get_field_table_name($field, $instance),
+    _serial_get_table_schema()
+  );
 }
 
 /**
  * Drops an assistant serial table for a deleted field.
  *
- * @param $field
- *   a serial field
- * @param $instance
- *   a deleted instance of that serial field
+ * @param array $field
+ *   Serial field.
+ * @param array $instance
+ *   Deleted instance of that serial field.
  */
-function _serial_drop_table($field, $instance) {
-  $table = _serial_get_field_table_name($field, $instance);
-  db_drop_table($table);
+function _serial_drop_table(array $field, array $instance) {
+  db_drop_table(_serial_get_field_table_name($field, $instance));
 }
 
 /**
  * Renames serial table(s) when a content type us renamed.
  *
- * @param $old_type
- *   an old node type machine name
- * @param $new_type
- *   a new node type machine name
+ * @param string $old_type
+ *   An old node type machine name.
+ * @param string $new_type
+ *   A new node type machine name.
  */
 function _serial_rename_tables($old_type, $new_type) {
-
   // Build the query to find all affected tables.
-  $query = db_select('field_config', 'f')->fields('f', array('field_name'));
-  $table_joined_alias = $query->join(
-      'field_config_instance', 'i',
-      '(f.field_name = i.field_name) AND ' .
-      '(f.type = :field_type) AND (i.bundle = :bundle_type)',
-      array(':field_type' => 'serial', ':bundle_type' => $new_type)
-  );
+  $query = db_select('field_config', 'f')
+    ->fields('f', array('field_name'));
 
-  // Add an access check and execute it.
-  $result = $query->addTag('node_access')->execute();
+  $query->join(
+    'field_config_instance',
+    'i',
+    "f.field_name = i.field_name AND f.type = 'serial' AND i.bundle = '$new_type'"
+  );
 
   // Rename each affected table.
-  foreach ($result as $record) {
-    $old_table = _serial_get_table_name($old_type, $record->field_name);
-    $new_table = _serial_get_table_name($new_type, $record->field_name);
-    db_rename_table($old_table, $new_table);
+  foreach ($query->addTag('node_access')->execute() as $record) {
+    db_rename_table(
+      _serial_get_table_name($old_type, $record->field_name),
+      _serial_get_table_name($new_type, $record->field_name)
+    );
   }
 }
 
 /**
  * Gets the name of the assistant table for a specific field.
  *
- * @param $field
- *   a serial field
- * @param $instance
- *   an instance of that serial field
- * @return
- *   the name of the assistant table of the specified field instance.
+ * @param array $field
+ *   Serial field.
+ * @param array $instance
+ *   An instance of that serial field.
+ *
+ * @return string
+ *   The name of the assistant table of the specified field instance.
  */
-function _serial_get_field_table_name($field, $instance) {
+function _serial_get_field_table_name(array $field, array $instance) {
   return _serial_get_table_name($instance['bundle'], $field['field_name']);
 }
 
 /**
  * Gets the name of the assistant table for a specific field.
  *
- * @param $bundle
- *   the name of the entity type that contains the field
- * @param $field_name
- *   the name of the field
- * @return
+ * @param string $bundle
+ *   The name of the entity type that contains the field.
+ * @param string $field_name
+ *   The name of the field.
+ *
+ * @return string
  *   the name of the assistant table of the specified field.
  */
 function _serial_get_table_name($bundle, $field_name) {
-  return db_escape_table( // be on the safe side
-    'serial_' . $bundle . '_' . $field_name);
+  return db_escape_table('serial_' . $bundle . '_' . $field_name);
 }
 
 /**
  * Gets the schema of the assistant tables for generating serial values.
  *
- * @return
- *   the assistant table schema.
+ * @return array
+ *   Assistant table schema.
  */
 function _serial_get_table_schema() {
   return array(
@@ -131,28 +129,24 @@ function _serial_get_table_schema() {
 /**
  * Generates a unique serial value (unique per node type).
  *
- * @param $nid
- *   id of the node for which to generate a serial value
- * @param $bundle
- *   a containing bundle (e.g. content type)
- * @param $field_name
- *   the field name
- * @param $delete
- *   indicates if temporary records should be deleted
- * @return
+ * @param string $bundle
+ *   Containing bundle (e.g. content type).
+ * @param string $field_name
+ *   The field name.
+ * @param bool $delete
+ *   Indicates if temporary records should be deleted.
+ *
+ * @return int
  *   the unique serial value number.
  */
 function _serial_generate_value($bundle, $field_name, $delete = TRUE) {
-
   // Get the name of the relevant table.
   $table = _serial_get_table_name($bundle, $field_name);
 
   // Insert a temporary record to get a new unique serial value.
   $uniqid = uniqid('', TRUE);
   $sid = db_insert($table)
-    ->fields(array(
-      'uniqid' => $uniqid,
-    ))
+    ->fields(array('uniqid' => $uniqid))
     ->execute();
 
   // If there's a reason why it's come back undefined, reset it.
@@ -160,9 +154,9 @@ function _serial_generate_value($bundle, $field_name, $delete = TRUE) {
 
   // Delete the temporary record.
   if ($delete && ($sid % 10) == 0) {
-  db_delete($table)
-    ->condition('uniqid', $uniqid, '=')
-    ->execute();
+    db_delete($table)
+      ->condition('uniqid', $uniqid)
+      ->execute();
   }
 
   // Return the new unique serial value.
@@ -172,46 +166,49 @@ function _serial_generate_value($bundle, $field_name, $delete = TRUE) {
 /**
  * Initializes the value of a new serial field in existing nodes.
  *
- * @param $bundle
- *   a containing bundle (e.g. content type)
- * @param $field_name
- *   the field name
- * @return
- *   the number of existing nodes that have been initialized.
+ * @todo Currently works only for nodes - should support comments and users.
+ *
+ * @param string $bundle
+ *   Containing bundle (e.g. content type).
+ * @param string $field_name
+ *   The field name.
+ *
+ * @return int
+ *   Number of existing nodes that have been initialized.
  */
 function _serial_init_old_nodes($bundle, $field_name) {
-  // Retrieve all the node ids of that type:
-  $query = "SELECT nid FROM {node} WHERE type = :type ORDER BY nid";
-    // TODO: Currently works only for nodes - should support comments and users.
-  $result = db_query($query, array('type' => $bundle));
-
-  // Allocate a serial number for every old node:
-  $count = 0;
-  foreach ($result as $node) {
-    $nid = $node->nid;
-    $node = node_load($nid);
-    $sid = _serial_generate_value($bundle, $field_name, FALSE);
-    $node->{$field_name} = array('und' => array(array('value' => $sid)));
+  $nodes = node_load_multiple(array(), array('type' => $bundle));
+
+  // Allocate a serial number for every old node.
+  foreach ($nodes as $node) {
+    $node->{$field_name} = array(
+      LANGUAGE_NONE => array(
+        array(
+          'value' => _serial_generate_value($bundle, $field_name, FALSE),
+        ),
+      ),
+    );
+
     node_save($node);
-    $count++;
   }
 
-  // Return the number of existing nodes that have been initialized:
-  return $count;
+  // Return the number of existing nodes that have been initialized.
+  return count($nodes);
 }
 
 /**
  * Retrieves all the managed serial fields.
  *
- * @return result set containing pairs of (node type name, field name).
+ * @return array
+ *   Pairs of node type name, field name.
  */
 function _serial_get_all_fields() {
   $query = db_select('field_config', 'f');
   $query->join('field_config_instance', 'i', 'i.field_name = f.field_name');
-  $query->fields('i', array('bundle', 'field_name'))
-        ->condition('f.type', 'serial', '=')
-        ->condition('i.deleted', 0, '=');
-  $result = $query->execute();
-  return $result->fetchAll();
-}
 
+  return $query->fields('i', array('bundle', 'field_name'))
+    ->condition('f.type', 'serial')
+    ->condition('i.deleted', 0)
+    ->execute()
+    ->fetchAll();
+}
diff --git a/serial.install b/serial.install
index 18e72bf..e3abdcf 100644
--- a/serial.install
+++ b/serial.install
@@ -1,24 +1,15 @@
 <?php
-
 /**
  * @file
  * Install, update and uninstall functions for the Serial module.
  */
 
 /**
- * Implements hook_uninstall().
- */
-function serial_uninstall() {
-  /*
-   * Schema tables are now dropped automatically.  However, if any work needs
-   * to be done before this, do it here.
-   */
-}
-
-/**
  * Implements hook_field_schema().
  */
 function serial_field_schema($field) {
+  $columns = array();
+
   switch ($field['type']) {
     case 'serial':
       $columns['value'] = array(
@@ -31,9 +22,8 @@ function serial_field_schema($field) {
       );
       break;
   }
-  return array(
-    'columns' => $columns
-  );
+
+  return array('columns' => $columns);
 }
 
 /**
@@ -42,45 +32,40 @@ function serial_field_schema($field) {
 function serial_schema() {
   // Get the standard schema:
   module_load_include('inc', 'serial');
-  $table_schema = _serial_get_table_schema();
 
-  // Build the schema by iteration over all the serial field instances:
+  $table_schema = _serial_get_table_schema();
   $schema = array();
-  $result = _serial_get_all_fields();
-  foreach ($result as $field) {
-    $table = _serial_get_table_name($field->bundle, $field->field_name);
-    $schema[$table] = $table_schema;
+
+  foreach (_serial_get_all_fields() as $field) {
+    $schema[_serial_get_table_name($field->bundle, $field->field_name)] = $table_schema;
   }
 
-  // Return the schema of all the assistant tables (one per serial field instance):
+  // Return the schema of all the assistant tables (one per field instance).
   return $schema;
 }
 
 /**
  * Upgrade path.
  *
- * Switches from nids to uniqid.
+ * Switches from nids to uniqids.
  */
 function serial_update_7130() {
-  // Get the new field schema.
   module_load_include('inc', 'serial');
+
   $table_schema = _serial_get_table_schema();
-  $uniqid_schema = $table_schema['fields']['uniqid'];
 
   // Update the schema of old assistant tables.
-  $result = _serial_get_all_fields();
-  foreach ($result as $field) {
+  foreach (_serial_get_all_fields() as $field) {
     // Empty the table.
     $table = _serial_get_table_name($field->bundle, $field->field_name);
     db_delete($table)->execute();
 
-    // Drop nid field and key
+    // Drop nid field and key.
     db_drop_field($table, 'nid');
     db_drop_unique_key($table, 'nid');
 
-    // Add uniqid field and key
-    db_add_field($table, 'uniqid', $uniqid_schema);
+    // Add uniqid field and key.
+    db_add_field($table, 'uniqid', $table_schema['fields']['uniqid']);
     db_add_unique_key($table, 'uniqid', array('uniqid'));
   }
 }
-
diff --git a/serial.module b/serial.module
index 688bb10..9567fab 100644
--- a/serial.module
+++ b/serial.module
@@ -1,14 +1,9 @@
 <?php
-
 /**
  * @file
  * The Serial module main file.
  */
 
-//==================//
-// Field Definition //
-//==================//
-
 /**
  * Implements hook_field_info().
  */
@@ -17,6 +12,9 @@ function serial_field_info() {
     'serial' => array(
       'label' => t('Serial'),
       'description' => t('Auto increment serial field type.'),
+      // The "property_type" should be defined for accessing the
+      // field by entity metadata wrapper.
+      'property_type' => 'serial',
       'default_widget' => 'serial',
       'default_formatter' => 'serial_formatter_default',
     ),
@@ -28,18 +26,19 @@ function serial_field_info() {
  */
 function serial_field_create_instance($instance) {
   $field = field_read_field($instance['field_name']);
-  if ($field['type'] == 'serial') {
+
+  if ('serial' == $field['type']) {
     // Create the assistant table:
     module_load_include('inc', 'serial');
     _serial_create_table($field, $instance);
 
-    // Set serial values for old objects
+    // Set serial values for old objects.
     $old_count = _serial_init_old_nodes($instance['bundle'], $field['field_name']);
-    if ($old_count) {
-      drupal_set_message(
-        t('Serial values have been automatically set for %count existing nodes.',
-          array('%count' => $old_count))
-      );
+
+    if ($old_count > 0) {
+      drupal_set_message(t('Serial values have been automatically set for %count existing nodes.', array(
+        '%count' => $old_count,
+      )));
     }
   }
 }
@@ -49,8 +48,9 @@ function serial_field_create_instance($instance) {
  */
 function serial_field_delete_instance($instance) {
   $field = field_read_field($instance['field_name']);
-  if ($field['type'] == 'serial') {
-    // Drop the assistant table:
+
+  if ('serial' == $field['type']) {
+    // Drop the assistant table.
     module_load_include('inc', 'serial');
     _serial_drop_table($field, $instance);
   }
@@ -60,18 +60,12 @@ function serial_field_delete_instance($instance) {
  * Implements hook_form_alter().
  */
 function serial_form_alter(&$form, $form_state, $form_id) {
+  if ('field_ui_field_settings_form' == $form_id && 'serial' == $form['field']['type']['#value']) {
+    drupal_set_message(t('Serial field %field has been created.', array(
+      '%field' => $form['field']['field_name']['#value'],
+    )));
 
-  if ($form_id == 'field_ui_field_settings_form' && $form['field']['type']['#value'] == 'serial') {
-    // Show messages:
-    $field_name = $form['field']['field_name']['#value'];
-    drupal_set_message(
-      t('Serial field %field has been created.',
-        array('%field' => $field_name))
-    );
-
-    // Go back to Managed Fields:
-    $type = $form['#bundle'];
-    drupal_goto("admin/structure/types/manage/$type/fields");
+    drupal_goto("admin/structure/types/manage/{$form['#bundle']}/fields");
   }
 }
 
@@ -79,19 +73,19 @@ function serial_form_alter(&$form, $form_state, $form_id) {
  * Implements hook_field_presave().
  */
 function serial_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
-  module_load_include('inc', 'serial');
   if (empty($items)) {
-    $sid = _serial_generate_value($instance['bundle'], $field['field_name']);
-    $items = array(array('value' => $sid));
+    module_load_include('inc', 'serial');
+
+    $items = array(array('value' => _serial_generate_value($instance['bundle'], $field['field_name'])));
   }
 }
 
-
 /**
  * Implements hook_field_is_empty().
  */
 function serial_field_is_empty($item, $field) {
-  return FALSE; // never should be treated as empty
+  // Never should be treated as empty.
+  return FALSE;
 }
 
 /**
@@ -116,39 +110,6 @@ function serial_node_type_update($info) {
   }
 }
 
-// Tokens for fields are currently not supported - http://drupal.org/node/691078.
-
-///**
-// * Implements hook_token_info().
-// */
-//function serial_token_info() {
-//  $type = array(
-//    'name' => t('Nodes'),
-//    'description' => t('Tokens related to individual nodes.'),
-//    'needs-data' => 'node',
-//  );
-//  $node['serial'] = array(
-//    'name' => t("Serial Field"),
-//    'description' =>  t('Serial field value (unique per node type)'),
-//    'needs-data' => 'node',
-//  );
-//  return array(
-//    'types' => array('node' => $type),
-//    'tokens' => array('node' => $node),
-//  );
-//}
-//
-///**
-// * Implements hook_tokens().
-// */
-//function serial_tokens($type, $tokens, $data, $options) {
-//  // TODO
-//}
-
-//=================//
-// Field Formatter //
-//=================//
-
 /**
  * Implements hook_field_formatter_info().
  */
@@ -157,7 +118,7 @@ function serial_field_formatter_info() {
     'serial_formatter_default' => array(
       'label' => t('Default'),
       'field types' => array('serial'),
-    )
+    ),
   );
 }
 
@@ -172,21 +133,17 @@ function serial_field_formatter_view($entity_type, $entity, $field, $instance, $
     $element[$delta] = array(
       '#markup' => theme('serial_formatter_default', array(
         'serial_id' => $item['value'],
-      ))
+      )),
     );
   }
+
   return $element;
 }
 
 /**
- * Theme Functions
- */
-
-/**
  * Implements hook_theme().
  */
 function serial_theme() {
-
   // Register the theme for the default formatter.
   return array(
     'serial_formatter_default' => array(
@@ -204,10 +161,6 @@ function theme_serial_formatter_default($variables) {
   return $variables['serial_id'];
 }
 
-//==============//
-// Field Widget //
-//==============//
-
 /**
  * Implements hook_field_widget_info().
  */
@@ -228,7 +181,6 @@ function serial_field_widget(&$form, &$form_state, $field, $instance, $items, $d
     'value' => array(
       '#type' => 'hidden',
       '#default_value' => $items[$delta]['value'],
-    )
+    ),
   );
 }
-