Allow to remove predefined order parameters when using "start order parameterized"

Current Situation

• If a user makes use of the operation "start order parameterized" then parameters can be added or modified, parameters cannot be removed.

Desired Behavior

• In addition, the user should be able to remove existing parameters of the order with JOC.

Resolution

• Currently the following command is used to add or to modify parameters of an order.

  <modify_order ...>
    <params>
      <param name="my_param_name" value="my_param_value"/>
      ...
    </params>
  </modify_order>
  

• If a parameter is omitted in the above command then this parameter is still active with JobScheduler.
• The JobScheduler doesn't provide a command to remove a parameter.
• Therefore it is not possible to remove a parameter from JOC.

Workaround

• Implement your scripts to handle empty parameter values in the same way as missing parameters.
• When using API methods to retrieve parameters then
  • an empty parameter returns an empty string.
  • a missing parameter returns null.
• For shell jobs
  • an empty parameter is represented by an environment variable with no value.
  • a missing parameteter is not assgined an environment variable.