Using an entity wrapper to change node->body value (with localization)

Question

I try to programmatically modify the body of a node using an entity wrapper.
In my Drupal installation I also use Locale module (language for node is 'en', for body it is 'und') and Revisioning module.

Now, I've created a simple code to do this task:

<?php
// in database: field_data_body->body_value = 'old_value'
$node = node_load(1);

$wrapper = entity_metadata_wrapper('node', $node);

print_r($wrapper->body->value->value());   // prints 'old_value'
$wrapper->body->value = 'new_value';
print_r($wrapper->body->value->value());   // still prints 'old_value'

$wrapper->save();
node_save($node);
?>

yet it seems not to make any changes to the node.

Although, if I've tried to change the title:

$wrapper->title = 'ABC';

everyting worked fine.

I guess it's the problem related to using localization, but I can't find sufficient documentation on how to achieve what I want.

Could someone tell me how can I put it to work?

Answer 1

Documentation is up to date now.

Examples from drupal.org :

 $wrapper->author = 0;
 $wrapper->url = 'dummy';
 $wrapper->author->mail = 'foo';
 $wrapper->author = NULL;
 $wrapper->author->set($GLOBALS['user']->uid);
 $wrapper->author->set($GLOBALS['user']);

 // Localization Here
 $wrapper->body->set(array('value' => "<b>The second body.</b>"));
 $wrapper->language('de');
 $wrapper->body->set(array('value' => "<b>Der zweite Text.</b>"));
 $wrapper->language(LANGUAGE_NONE);
 $wrapper->set($node);

 $wrapper->reference->name->set('foo');
 $wrapper->reference->set($wrapper);
 $wrapper->save();
 $wrapper->delete();
 $wrapper->type->set('article');
 $wrapper->author = $user->uid;
 $wrapper->{$property}[0] = '2009-10-05';
 $wrapper->field_image = array('fid' => $file->fid);
 $wrapper->$name->value();
 $wrapper->parent[] = $term_parent2;
 $wrapper->field_tags[1] = $term_parent;
 $wrapper->field_tags->set(array(2));
 $wrapper->field_tags = NULL;
 $wrapper->$field_name->set(NULL);
 $wrapper->field_text[0] = 'the text';
 $wrapper->field_text[0]->set(array('value' => "<b>The second body.</b>"));
 $wrapper->field_text2->summary = 'the summary';
 $wrapper->field_text2->value = 'the text';
 $wrapper->field_file[0] = array('fid' => $file->fid, 'display' => FALSE);
 $wrapper->field_file[0]->description = 'foo';
 $wrapper->field_file[0]->display = TRUE;
 $wrapper->field_file[1]->file = $file;
 $wrapper->field_file[] = array('description' => 'test');
 $wrapper->field_file = NULL;
 $wrapper->field_image = array('fid' => $file->fid);
 $wrapper->field_image->alt = 'foo';
 $wrapper->field_image->file = $file;
 $wrapper->field_image = array();

You can follow this link to see full documentation and examples about entity metadata wrappers and localization.

Documentation about entity metadata wrappers on Drupal.org