From Forum Nokia Wiki

ID	CS000991	Creation date	May 28, 2008
Platform	S60 3rd Edition, FP1	Tested on devices	Nokia N93
Category	Symbian C++	Subcategory	Files/Data

Keywords (APIs, classes, methods, functions): RScheduler, TSchedulerItemRef, TTaskSchedulerCondition, TTaskInfo, TTsTime, RProperty, RScheduler::Connect(), RScheduler::Register(), RScheduler::Close(), RScheduler::CreatePersistentSchedule(), RScheduler::ScheduleTask(), RScheduler::EditSchedule(), RScheduler::EnableSchedule(), RScheduler::DisableSchedule(), TTsTime::SetLocalTime(), RProperty::Define(), RProperty::Set(), RProperty::Delete()

Overview

This code snippet shows how to create, disable, enable, and edit a condition-based schedule using the class RScheduler. When schedules are created, they are enabled by default. By disabling a schedule the scheduled tasks are not executed even if they become due. The RScheduler methods EnableSchedule() and DisableSchedule() are used to enable/disable the example schedule. There are separate methods for time-based and condition-based schedules with different parameters for editing schedules. The condition-based EditSchedule() is used for editing the schedule in this example.

This snippet can be self-signed.

MMP file

The following libraries are required:

LIBRARY             schsvr.lib

Preconditions

ExampleTaskHandler.exe must be created before this code snippet can be executed. See CS000986 - Creating and registering a task handler with RScheduler.

Resource files

.rss

RESOURCE MENU_PANE r_schedulerexample_menu
    {
    items = 
        {
        //...
        MENU_ITEM {command = EEditExample;             txt = "EditExample";},
        //...
        MENU_ITEM {command = EAknSoftkeyExit;          txt = "Exit";}
        };
    }

.hrh

enum TSchedulerExampleIds
    {
   //...
    EEditExample,
    //...
    };

Header file

#ifndef __SCHEDULEREXAMPLEAPPUI_H__
#define __SCHEDULEREXAMPLEAPPUI_H__
 
#include <csch_cli.h> // RScheduler
#include <schinfo.h>  // TSchedulerItemRef, TTaskInfo... 
 
class CSchedulerExampleAppUi : public CAknAppUi
    {
    //...
public:   
    void HandleCommandL(TInt aCommand);
    //...
private:    
    void CreateConditionVariableL();
   
    void SetConditionVariableL(TInt aKeyValue); 
    
    void DeleteConditionVariableL();
    
    TInt EnableOrDisableSchedule(RScheduler& aScheduler, TInt aScheduleId, TBool aDoEnable);
    
    TInt CreateInitialConditionScheduleWithTaskL(
                                            TSchedulerItemRef& aSchedulerItem,
                                            RScheduler& aScheduler,
                                            TInt aKeyId, TInt aExpectedValue,
                                            const TTsTime& aDefaultRunTime
                                            );
 
 
 
    //...    
private:
 
    RScheduler iScheduler;
};
    
#endif // __SCHEDULEREXAMPLEAPPUI_H__

Source file

#include <e32property.h>
 
const TUid KExampleUid = TUid::Uid(0xE0060BBB); //UID3 from .mmp file
const TInt KExampleKey = 1;
 
void CSchedulerExampleAppUi::ConstructL()
    {
    //...
    User::LeaveIfError(iScheduler.Connect());
    
    _LIT(KExampleTaskHandlerExe, "ExampleTaskHandler.exe");
    TFileName exampleHandler(KExampleTaskHandlerExe);
        
    User::LeaveIfError(iScheduler.Register(exampleHandler, CActive::EPriorityStandard));    
    }
    
CSchedulerExampleAppUi::~CSchedulerExampleAppUi()
    {
 
    //...    
    iScheduler.Close(); 
    
    DeleteConditionVariableL(); 
    }    
 
void CSchedulerExampleAppUi::HandleCommandL(TInt aCommand)
  {
  TBuf<100> Text1; //first line of dialog text 
  TBuf<100> Text2; //second line of dialog text
      
  switch(aCommand)
    {
    case EEikCmdExit:
    case EAknSoftkeyExit:
      Exit();
      break;
//...
    case EEditExample:
      {
      TInt err(KErrNone);
                      
      CreateConditionVariableL();
      TSchedulerItemRef tempRef;
            
      TTsTime defaultTime;
      TTime time;
      time.HomeTime();
      time = time.operator+(TTimeIntervalMonths(1));
      defaultTime.SetLocalTime( time );
  
      err = CreateInitialConditionScheduleWithTaskL(tempRef, iScheduler, 
KExampleKey, 1, defaultTime );
      
      //disable the schedule
      err = EnableOrDisableSchedule(iScheduler, tempRef.iHandle, EFalse);
                
      //set condition variable to trigger the example task    
      SetConditionVariableL(1);
      
      //NOTE: nothing happens because the schedule is disabled!         
      //User::After(1000*1000*2);
 
      //set condition variable not to trigger the example task                      
      SetConditionVariableL(2);
        
      //enable the schedule again
      err = EnableOrDisableSchedule(iScheduler, tempRef.iHandle, ETrue);
            
      if(err == KErrNone)
        Text1.Append(_L("Schedule is enabled!"));      
            
      CArrayFixFlat<TTaskSchedulerCondition>* conditions = 
new (ELeave) CArrayFixFlat<TTaskSchedulerCondition>(1);        
                      
      CleanupStack::PushL(conditions);
      TTaskSchedulerCondition newCondition;
      newCondition.iCategory    = KExampleUid;
      newCondition.iKey         = KExampleKey;
      newCondition.iState       = 2;
      newCondition.iType        = TTaskSchedulerCondition::EEquals;
      conditions->AppendL(newCondition);
  
      //edit condition schedule to trigger the example task when 
      //condition variable equals to state 2
      err = iScheduler.EditSchedule(tempRef.iHandle, *conditions, defaultTime);
         
      if(err == KErrNone)
        Text2.Append(_L("Schedule is edited!"));
            
      CEikonEnv::Static()->InfoWinL(Text1, Text2);   
         
      //Task Scheduler launches the example task...      
            
      CleanupStack::PopAndDestroy(conditions);
      }
      break;
      
   default:
     //Panic(ESchedulerExampleUi);
     break;
     }
  }  
    
 
void CSchedulerExampleAppUi::CreateConditionVariableL()
  {
  TInt ret = RProperty::Define(KExampleUid, KExampleKey, RProperty::EInt);
  
  if (ret != KErrAlreadyExists)
    {      
    User::LeaveIfError(ret);
    }
  }
 
void CSchedulerExampleAppUi::SetConditionVariableL(TInt aKeyValue)              
  {  
  TInt ret = RProperty::Set(KExampleUid, KExampleKey, aKeyValue);
  
  User::LeaveIfError(ret);
  }
 
void CSchedulerExampleAppUi::DeleteConditionVariableL()
  {
  TInt ret = RProperty::Delete(KExampleUid, KExampleKey);
  
  if (ret != KErrNotFound)
    {
    User::LeaveIfError(ret);
    }
  }
 
TInt CSchedulerExampleAppUi::EnableOrDisableSchedule(
                                        RScheduler& aScheduler, 
                                        TInt aScheduleId, 
                                        TBool aDoEnable
                                        )
  {
  TInt ret(KErrNone);
  
  if(aDoEnable)
    {
    ret = aScheduler.EnableSchedule(aScheduleId);
    }
  else
    {
    ret = aScheduler.DisableSchedule(aScheduleId);
    }
  
  return ret;
  }
 
TInt CSchedulerExampleAppUi::CreateInitialConditionScheduleWithTaskL(
                       TSchedulerItemRef& aSchedulerItem,
                       RScheduler& aScheduler,
                       TInt aKeyId, TInt aTriggerValue,
                       const TTsTime& aDefaultRunTime
                    )
    {
    TInt ret(KErrNone);
    
    aSchedulerItem.iName = _L("Edit Schedule Example");
    
    CArrayFixFlat<TTaskSchedulerCondition>* conditions = 
new (ELeave) CArrayFixFlat<TTaskSchedulerCondition>(1);        
    CleanupStack::PushL(conditions);
    
    TTaskSchedulerCondition condition;
    condition.iCategory     = KExampleUid;
    condition.iKey          = aKeyId;
    condition.iState        = aTriggerValue;
    condition.iType         = TTaskSchedulerCondition::EEquals;
    conditions->AppendL(condition);
    
    ret = aScheduler.CreatePersistentSchedule(aSchedulerItem, *conditions, aDefaultRunTime);
    
    if (ret == KErrNone)
      {
      TTaskInfo taskInfo;
      taskInfo.iTaskId = 0;
      taskInfo.iName = _L("ExampleTask4");
      taskInfo.iPriority = 2;
      taskInfo.iRepeat = 0;
      HBufC* data = _L("ExampleData4").AllocLC();
        
      // schedule the example task
      ret = aScheduler.ScheduleTask(taskInfo, *data, aSchedulerItem.iHandle);
      CleanupStack::PopAndDestroy(); // data
      }
    else
      {
      //Creating persistent schedule failed, do something...    
      }
 
    CleanupStack::PopAndDestroy(conditions);
    
    return ret;
    }

Postconditions

The condition-based schedule with one example task has been created and the task execution is triggered using the Publish and Subscribe mechanism after the schedule is enabled and edited.

See also

• CS000986 - Creating and registering a task handler with RScheduler
• CS000987 - Creating persistent and transient schedules with RScheduler
• CS000988 - Creating a condition-based schedule with RScheduler
• CS000989 - Getting schedule and task info using RScheduler
• CS000990 - Getting schedule and task count using RScheduler
• CS000992 - Deleting schedules and tasks using RScheduler