diff --git a/feeds.api.php b/feeds.api.php
index 9aee118..b40c310 100644
--- a/feeds.api.php
+++ b/feeds.api.php
@@ -459,10 +459,6 @@ function my_module_mapper_unique(FeedsSource $source, $entity_type, $bundle, $ta
 /**
  * Example of the preprocess_callbacks specified in hook_feeds_processor_targets().
  *
- * @param FeedsSource $source
- *   The Feed source.
- * @param object $entity
- *   The entity being processed.
  * @param array $target
  *   The full target definition.
  * @param array &$mapping
@@ -470,7 +466,7 @@ function my_module_mapper_unique(FeedsSource $source, $entity_type, $bundle, $ta
  *
  * @see hook_feeds_processor_targets()
  */
-function my_module_preprocess_callback(FeedsSource $source, $entity, array $target, array &$mapping) {
+function my_module_preprocess_callback(array $target, array &$mapping) {
   // Add in default values.
   $mapping += array('setting_value' => TRUE);
 }
diff --git a/mappers/locale.inc b/mappers/locale.inc
index f1aef3a..5f235a1 100644
--- a/mappers/locale.inc
+++ b/mappers/locale.inc
@@ -19,7 +19,7 @@ function locale_feeds_processor_targets_alter(array &$targets, $entity_type, $bu
 /**
  * Preprocess callback that sets the configured mapping language.
  */
-function locale_feeds_preprocess_callback(FeedsSource $source, $target_item, array $target, array &$mapping) {
+function locale_feeds_preprocess_callback(array $target, array &$mapping) {
   if (empty($mapping['field_language'])) {
     return;
   }
diff --git a/plugins/FeedsProcessor.inc b/plugins/FeedsProcessor.inc
index 4ed85aa..d7102dc 100644
--- a/plugins/FeedsProcessor.inc
+++ b/plugins/FeedsProcessor.inc
@@ -706,7 +706,7 @@ abstract class FeedsProcessor extends FeedsPlugin {
     // Many mappers add to existing fields rather than replacing them. Hence we
     // need to clear target elements of each item before mapping in case we are
     // mapping on a prepopulated item such as an existing node.
-    foreach ($this->config['mappings'] as $mapping) {
+    foreach ($this->getMappings() as $mapping) {
       if (isset($targets[$mapping['target']]['real_target'])) {
         $target_name = $targets[$mapping['target']]['real_target'];
       }
@@ -714,20 +714,12 @@ abstract class FeedsProcessor extends FeedsPlugin {
         $target_name = $mapping['target'];
       }
 
-      // If the target is a field and a mapping language is specified, empty the
-      // value for the targeted language only.
+      // If the target is a field empty the value for the targeted language
+      // only.
       // In all other cases, just empty the target completely.
-      // @todo The definitive language to use is decided later, in
-      // ::mapToTarget(). In theory values for the wrong language could be
-      // emptied.
-      if (isset($mapping['field_language']) && isset($fields[$target_name])) {
-        // First check if the specified language is available.
-        $languages = language_list('enabled');
-        if (!isset($languages[1][$mapping['field_language']])) {
-          $mapping['field_language'] = LANGUAGE_NONE;
-        }
+      if (isset($fields[$target_name])) {
         // Empty the target for the specified language.
-        $target_item->{$target_name}[$mapping['field_language']] = array();
+        $target_item->{$target_name}[$mapping['language']] = array();
       }
       else {
         // Empty the whole target.
@@ -739,7 +731,7 @@ abstract class FeedsProcessor extends FeedsPlugin {
     // the parser's getSourceElement() method to retrieve the value of the
     // source element and pass it to the processor's setTargetElement() to stick
     // it on the right place of the target item.
-    foreach ($this->config['mappings'] as $mapping) {
+    foreach ($this->getMappings() as $mapping) {
       $value = $this->getSourceValue($source, $result, $mapping['source']);
 
       $this->mapToTarget($source, $mapping['target'], $target_item, $value, $mapping);
@@ -786,24 +778,6 @@ abstract class FeedsProcessor extends FeedsPlugin {
   protected function mapToTarget(FeedsSource $source, $target, &$target_item, $value, array $mapping) {
     $targets = $this->getCachedTargets();
 
-    if (isset($targets[$target]['preprocess_callbacks'])) {
-      foreach ($targets[$target]['preprocess_callbacks'] as $callback) {
-        call_user_func_array($callback, array($source, $target_item, $targets[$target], &$mapping));
-      }
-    }
-
-    // Ensure there's always a language set.
-    if (empty($mapping['language'])) {
-      $mapping['language'] = LANGUAGE_NONE;
-    }
-    else {
-      // Check if the configured language is available. If not, fallback to LANGUAGE_NONE.
-      $languages = language_list('enabled');
-      if (!isset($languages[1][$mapping['language']])) {
-        $mapping['language'] = LANGUAGE_NONE;
-      }
-    }
-
     // Map the source element's value to the target.
     // If the mapping specifies a callback method, use the callback instead of
     // setTargetElement().
@@ -947,7 +921,38 @@ abstract class FeedsProcessor extends FeedsPlugin {
    * Get mappings.
    */
   public function getMappings() {
-    return isset($this->config['mappings']) ? $this->config['mappings'] : array();
+    $cache = &drupal_static('FeedsProcessor::getMappings', array());
+
+    if (!isset($cache[$this->id])) {
+      $mappings = $this->config['mappings'];
+      $targets = $this->getCachedTargets();
+      $languages = language_list('enabled');
+
+      foreach ($mappings as &$mapping) {
+
+        if (isset($targets[$mapping['target']]['preprocess_callbacks'])) {
+          foreach ($targets[$mapping['target']]['preprocess_callbacks'] as $callback) {
+            call_user_func_array($callback, array($targets[$mapping['target']], &$mapping));
+          }
+        }
+
+        // Ensure there's always a language set.
+        if (empty($mapping['language'])) {
+          $mapping['language'] = LANGUAGE_NONE;
+        }
+        else {
+          // Check if the configured language is available. If not, fallback to
+          // LANGUAGE_NONE.
+          if (!isset($languages[1][$mapping['language']])) {
+            $mapping['language'] = LANGUAGE_NONE;
+          }
+        }
+      }
+
+      $cache[$this->id] = $mappings;
+    }
+
+    return $cache[$this->id];
   }
 
   /**
@@ -1088,7 +1093,7 @@ abstract class FeedsProcessor extends FeedsPlugin {
   protected function uniqueTargets(FeedsSource $source, FeedsParserResult $result) {
     $parser = feeds_importer($this->id)->parser;
     $targets = array();
-    foreach ($this->config['mappings'] as $mapping) {
+    foreach ($this->getMappings() as $mapping) {
       if (!empty($mapping['unique'])) {
         // Invoke the parser's getSourceElement to retrieve the value for this
         // mapping's source.
@@ -1152,7 +1157,7 @@ abstract class FeedsProcessor extends FeedsPlugin {
   protected function hash($item) {
     $sources = feeds_importer($this->id)->parser->getMappingSourceList();
     $mapped_item = array_intersect_key($item, array_flip($sources));
-    return hash('md5', serialize($mapped_item) . serialize($this->config['mappings']));
+    return hash('md5', serialize($mapped_item) . serialize($this->getMappings()));
   }
 
   /**
diff --git a/tests/feeds_tests.module b/tests/feeds_tests.module
index 44fa2e8..2eea4d7 100644
--- a/tests/feeds_tests.module
+++ b/tests/feeds_tests.module
@@ -209,7 +209,7 @@ function feeds_tests_feeds_processor_targets_alter(array &$targets, $entity_type
  *
  * @see feeds_tests_feeds_processor_targets()
  */
-function feeds_tests_preprocess_callback(FeedsSource $source, $target_item, $target, array &$mapping) {
+function feeds_tests_preprocess_callback(array $target, array &$mapping) {
   $mapping['required_value'] = TRUE;
 }