Issue #7108: add hook to respond to tranlsation set change

core/modules/translation/tests/translation.api.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * @file
+ * Hooks for translation module.
+ */
+
+/**
+ * Respond to changes in a node's translation set.
+ *
+ * The node object is extended with a 'translation_change' array containing
+ * both the old and new tnid.
+ *
+ * @param Node $node
+ *   The node being acted upon.
+ */
+function hook_node_translation_change(Node $node) {
+  $update = db_update('my_table')
+    ->fields(array(
+      'tnid' => $node->translation_change['new_tnid'],
+    ))
+    ->condition('tnid', $node->tnid, '=')
+    ->execute();
+}

core/modules/translation/tests/translation.test

@@ -24,8 +24,23 @@ class TranslationTestCase extends BackdropWebTestCase {
     parent::setUp('node', 'language', 'locale', 'translation', 'translation_test');
 
     // Setup users.
-    $this->admin_user = $this->backdropCreateUser(array('bypass node access', 'administer nodes', 'administer languages', 'administer content types', 'administer blocks', 'access administration pages', 'translate content'));
-    $this->translator = $this->backdropCreateUser(array('create page content', 'edit own page content', 'translate content'));
+    $this->admin_user = $this->backdropCreateUser(
+      array(
+        'bypass node access',
+        'administer nodes',
+        'administer languages',
+        'administer content types',
+        'administer blocks',
+        'access administration pages',
+        'translate content',
+      ));
+    $this->translator = $this->backdropCreateUser(
+      array(
+        'create page content',
+        'edit own page content',
+        'delete own page content',
+        'translate content',
+      ));
 
     $this->backdropLogin($this->admin_user);
 
@@ -126,6 +141,11 @@ class TranslationTestCase extends BackdropWebTestCase {
     $this->backdropPost('node/' . $node_translation->nid . '/edit', $edit, t('Save'));
     $this->assertRaw(t('Page %title has been updated.', array('%title' => $node_translation_title)), 'Translated node updated.');
 
+    // Delete the source node.
+    $this->backdropPost('node/' . $node->nid . '/delete', array(), t('Delete'));
+    // Assert that hook_translation_change() was called.
+    $this->assertEqual(state_get('translation_change_called', ''), $node->nid, t('hook_node_translation_change() was called.'));
+
     // Confirm that disabled languages are an option for translators when
     // creating nodes.
     $this->backdropGet('node/add/page');

core/modules/translation/tests/translation_test/translation_test.module

@@ -10,3 +10,10 @@
 function translation_test_node_insert(Node $node) {
   backdrop_write_record('node', $node, 'nid');
 }
+
+/**
+ * Implementation of hook_node_translation_change().
+ */
+function translation_test_node_translation_change($node) {
+  state_set('translation_change_called', $node->nid);
+}

core/modules/translation/translation.module

@@ -485,11 +485,22 @@ function translation_remove_from_set($node) {
 
     // Determine which nodes to apply the update to.
     $set_nids = db_query('SELECT nid FROM {node} WHERE tnid = :tnid', array(':tnid' => $node->tnid))->fetchCol();
+
+    $node->translation_change = array(
+      'old_tnid' => $node->tnid,
+      'new_tnid' => 0,
+      // Determine the remaining former member of the translation set.
+      // May be needed e.g. to reassign existing data from the tnid to this nid.
+      'remaining_nid' => $set_nids,
+    );
+
     if (count($set_nids) == 1) {
       // There is only one node left in the set: remove the set altogether.
       $query
         ->condition('tnid', $node->tnid)
         ->execute();
+      // Allow other modules to respond to the removal of this translation set.
+      node_invoke($node, 'translation_change');
 
       $flush_set = TRUE;
     }
@@ -502,10 +513,16 @@ function translation_remove_from_set($node) {
       // we pick a new source - preferably one that is up to date.
       if ($node->tnid == $node->nid) {
         $new_tnid = db_query('SELECT nid FROM {node} WHERE tnid = :tnid ORDER BY translate ASC, nid ASC', array(':tnid' => $node->tnid))->fetchField();
+        $node->translation_change = array(
+          'old_tnid' => $node->tnid,
+          'new_tnid' => $new_tnid,
+        );
         db_update('node')
           ->fields(array('tnid' => $new_tnid))
           ->condition('tnid', $node->tnid)
           ->execute();
+        // Allow other modules to respond to the removal of this translation set.
+        node_invoke($node, 'translation_change');
 
         $flush_set = TRUE;
       }