Re: Optional user field webservice

For this at first you have to find the external function in services.php of Moodle which u r using,

find out the methodname and classpath, classpath is the path of the methodname.

You have to customize the method parameters.

Example---->

For core_user_create_users external function

'core_user_create_users' => array(
'classname' => 'core_user_external',           
'methodname' => 'create_users',                  #method name
'classpath' => 'user/externallib.php',             #path
'description' => 'Create users.',
'type' => 'write',
'capabilities'=> 'moodle/user:create',
),

Have to customize---->

public static function create_users_parameters()

You will get help from the link

http://docs.moodle.org/dev/Creating_a_web_service_and_a_web_service_function