P_PPM_TaskReadyToStart

@VDM.viewType: #COMPOSITE
@VDM.private: true
@AbapCatalog.sqlViewName: 'PPPMTSKRDYTOST'
@AccessControl.authorizationCheck: #PRIVILEGED_ONLY
@ClientHandling.algorithm: #SESSION_VARIABLE
@ObjectModel.usageType.serviceQuality: #X
@ObjectModel.usageType.sizeCategory:  #L
@ObjectModel.usageType.dataClass:  #MIXED
@ObjectModel.representativeKey: 'TaskUUID'

/*  Specification: 1 record is returned for every task */
define view P_PPM_TaskReadyToStart as select
             from I_PPM_Task as Task
// A task is ready to start if it has no predecessor

  left outer join P_PPM_SuccessorTskReadyToStart as SuccessorReadyToWork

                              on Task.TaskUUID                              = SuccessorReadyToWork.SuccessorTaskUUID

/* Or when defined as successor in relationships, the relation shows that all its predecessors are in states
   that enable the start of the successor */
/*  left outer join P_PPM_TaskNotReadyToStart      as SuccessorNotReadyToWork
               on Task.TaskUUID                              = SuccessorNotReadyToWork.SuccessorTaskUUID */

{
  key Task.TaskUUID,
      Task.ExternalId as Task,
     cast ( case
      // Task has no predeccessors which blocks its start

         //when SuccessorNotReadyToWork.SuccessorTaskUUID is null then

       when SuccessorReadyToWork.IsTaskReadyToStart = 'X' then
          case
      // check status 'released'

            when Task.TaskProcessingStatus = '10' or Task.TaskProcessingStatus = '11' then
                  'X'
     //  check status 'blocked'

/*          when Task.TaskProcessingStatus = '20' or Task.TaskProcessingStatus = '21' then
              ' ' */
            else
              ' '
          end
        when SuccessorReadyToWork.SuccessorTaskUUID is not null and SuccessorReadyToWork.IsTaskReadyToStart = ' ' then
              ' '
         when Task.TaskProcessingStatus = '10' or Task.TaskProcessingStatus = '11' then
           'X'
        else
      // Task has at least 1 predecessor not ready to start

              ' '
      end as xfeld preserving type ) as IsTaskReadyToStart

}