title: Adding products to PrestaShop 1.6.0.9 with WebService
body: <p>I am trying to add products to my shop powered by PrestaShop 1.6.0.9. Here is my code:</p>
  
  <pre><code>&lt;?php
      ini_set('display_errors',1);
      ini_set('display_startup_errors',1);
      error_reporting(-1);
      define('DEBUG', true);
      define('_PS_DEBUG_SQL', true);
      define('PS_SHOP_PATH', 'http://myshop.com');
      define('PS_WS_AUTH_KEY', 'E6R9IDPK2R519WB9QAJ45MUACZ9GANC2');
  
      require_once('PSWebServiceLibrary.php');
  
      try {
              $webService = new PrestaShopWebservice(PS_SHOP_PATH, PS_WS_AUTH_KEY, DEBUG);
              $opt = array('resource' =&gt; 'products');
  
              $xml = $webService-&gt;get(array('url' =&gt; PS_SHOP_PATH.'/api/products?schema=synopsis'));
              $resources = $xml-&gt;children()-&gt;children();
  
              unset($resources-&gt;position_in_category);
              unset($resources-&gt;manufacturer_name);
  
              $resources-&gt;price = '1000';
              $resources-&gt;active = '1';
              $resources-&gt;quantity = '50';
              $resources-&gt;link_rewrite = 'blabla';
              $resources-&gt;name-&gt;language[0][0] = 'blabla';
              $resources-&gt;description-&gt;language[0][0] = '&lt;p&gt;blabla&lt;/p&gt;';
              $resources-&gt;description_short-&gt;language[0][0] = 'blabla';
              $resources-&gt;associations = '';
  
              $opt = array('resource' =&gt; 'products');
              $opt['postXml'] = $xml-&gt;asXML();
              $xml = $webService-&gt;add($opt); 
      }
      catch (PrestaShopWebserviceException $ex) {
          echo 'Other error: &lt;br/&gt;'.$ex-&gt;getMessage();
      }
  ?&gt;
  </code></pre>
  
  <p>But I receive this error as XML:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;prestashop xmlns:xlink="http://www.w3.org/1999/xlink"&gt;
  &lt;errors&gt;
  &lt;error&gt;
  &lt;code&gt;&lt;![CDATA[127]]&gt;&lt;/code&gt;
  &lt;message&gt;&lt;![CDATA[XML error : String could not be parsed as XML
  XML length : 7891
  Original XML : %3C%3Fxml+version%3D%221.0%22+encoding%3D%22UTF-8%22%3F%3E%0A%3Cprestashop+xmlns%3Axlink%3D...................
  &lt;/error&gt;
  &lt;/errors&gt;
  &lt;/prestashop&gt;
  </code></pre>
  
  <p>I receive  error for every update or insert. What can be the problem? And how can I fix this? My PrestaShop version is 1.6.0.9. </p>