If that is the exact error you are getting it seems very confusing to me. The include for the cart file should include another require once for the cart definition file. The definition file is where this function should be defined.
Perhaps you should try adding in a require once for the cart definition file to ensure that it is included before the call to GetContents. Here is what the require once should look like:
php:
require_once("WA_eCart_Definition_PHP.php");
I have not ever seen before where a php page throws an error about the function if it has been defined. It seems like either the include is being ignored, or that the file, or code for that file is not present. Here is what the function call looks like in the file:
php:
function GetContent() {
if ($this->PersistanceType == 0) { //Session
$this->Items = $this->Session_GetContent();
}
if ($this->PersistanceType == 1) { //Cookie
$this->Items = $this->Cookie_GetContent();
}
}
