CMsvOperation Class Reference

#include <mw/msvapi.h>

class CMsvOperation : public CActive, public CActive

Inherits from

Detailed Description

Defines an interface for use by objects which control asynchronous commands in the messaging system.

Such objects are returned by CMsvEntry and User Interface MTM functions that complete asynchronously. The interface allows clients to:

1. get progress information about the operation

2. cancel the operation

3. be signalled asynchronously when the operation completes; a client passes in a TRequestStatus of a suitable active object for this purpose

The client only needs to understand the CMsvOperation interface, not the concrete implementation used.

Writing derived classes:

As the base class interface for User Interface MTMs, CBaseUiMtm, defines functions that return CMsvOperation objects for control of asynchronous operations, implementers of these MTM components are required to provide suitable derived classes. For example, if CBaseUiMtm::EditL() is implemented to provide message editing, a CMsvOperation -derived class would be provided that completes when the editing operation is complete.

Concrete derived classes must provide implementations of the pure virtual DoCancel() and RunL() functions defined by CActive. DoCancel() should be provided in the normal way to cancel the operation. RunL() should, in addition to any other required functionality, always end by signalling the client that the operation is complete with a suitable completion code.

Member Attribute Documentation

iMsvSession

CMsvSession &iMsvSession[protected]

Message Server session used by object. This is set by the constructor.

iMtm

TUid iMtm[protected]

The UID of the MTM associated with the operation.

The appropriate value should be set by the derived class constructor.

See also: Mtm()

iObserverRequestStatus

TRequestStatus &iObserverRequestStatus[protected]

Request status of the operation observer.

This is the aObserverRequestStatus passed in the constructor.

iService

TMsvId iService[protected]

The ID of the service that is associated with this operation.

Usually, the derived class constructor will contain a suitable argument to allow the caller to set this.

See also: Service()

Constructor & Destructor Documentation

CMsvOperation ( CMsvSession &, TInt, TRequestStatus & )

IMPORT_CCMsvOperation(CMsvSession &aMsvSession,
TIntaPriority,
TRequestStatus &aObserverRequestStatus
)

Constructor. This is called by MTM implementers from the derived class constructor.

CMsvOperation-derived objects are not created by message client applications. The constructor uses the CMsvSession object to obtain a ID for the operation. This ID can be accessed by clients through Id().

aPriority is the priority used by the active object. Typically, this is EPriorityStandard.

aObserverRequestStatus is the asynchronous status object of an active object provided by the caller. The derived class is required to signal the caller through this when the operation completes. It is stored by the constructor in the iObserverRequestStatus member.

Parameters
aMsvSessionSession object
aPriorityActive object priority
aObserverRequestStatusRequest status of operation observer

~CMsvOperation ( )

IMPORT_C~CMsvOperation()

Destructor.

This base class function takes no action. Derived classes should implement a destructor to do the clean up tasks that they require. Minimally, they should call Cancel() to cancel any outstanding request.

Member Function Documentation

Extension_ ( TUint, TAny *&, TAny * )

IMPORT_C TIntExtension_(TUintaExtensionId,
TAny *&a0,
TAny *a1
)[protected, virtual]

Reimplemented from CActive::Extension_(TUint,TAny *&,TAny *)

The extension method provides a polymorphic behaviour to call the correct SystemProgress function.

Parameters
aExtensionIdThe Uid passed in as KUIDMsgMsvSystemProgress to obtain the System Progress.
Return Value
KErrExtensionNotSupported retuned if no Extension_ function is overriddden by the derived class.

FinalProgress ( )

IMPORT_C const TDesC8 &FinalProgress()[virtual]

Gets information about a completed operation.

Unlike ProgressL(), this is guaranteed to provide status information reflecting the outcome of a completed operation.

Requirements:

The default implementation of this function returns the result from ProgressL(). If the operation is active or ProgressL() leaves, a panic occurs.

A derived class should implement the function to meet the requirement to provide appropriate final status information. Typically, on active object completion, it will store progress information in a private member, and return that stored information from this function.

Return Value
Descriptor holding progress information
Panic Codes
MSGS285 Operation is active
MSGS286 Could not get final progress information, as

Id ( )

TMsvOp Id()const [inline]

Gets the operation ID.

This ID is unique within a Message Server session. The ID allows the client to keep track of different operations.

Return Value
The ID of the operation

Mtm ( )

IMPORT_C TUidMtm()const [virtual]

Gets the UID of the MTM associated with the operation.

This UID can be used to determine the appropriate method of getting information from a progress descriptor.

The default implementation returns iMtm.

See also: ProgressL()

Return Value
The UID of the MTM associated with the operation

ProgressL ( )

const TDesC8 &ProgressL()[pure virtual]

Gets information on the progress of the operation.

All operations on local entries share the same progress information format, which defined by TMsvLocalOperationProgress.

For MTM-specific operations, progress information can be extracted by calling CBaseUiMtm::GetProgress() or displayed by CBaseUiMtm::DisplayProgressSummary() on the appropriate User Interface MTM.

Requirements:

Derived classes should implement this function so that the client can check on the progress of the operation. The function should share an understanding of the format of the buffer with the implementations of CBaseUiMtm::GetProgress() and CBaseUiMtm::DisplayProgressSummary() in the User Interface MTM. The arguments of CBaseUiMtm::GetProgress() show some information that should be included where appropriate.

Return Value
Descriptor holding progress information. The maximum buffer size should be KMsvProgressBufferLength (defined in msvipc.h).
Leave Codes
KErrNotReadyThe operation has not yet been started: it has been queued for execution in the Message Server

Service ( )

TMsvId Service()const [inline]

Gets the ID of the service that is associated with this operation.

If the operation is not associated with a service, the function returns KMsvLocalServiceIndexEntryId.

Return Value
ID of the service associated with the operation

SystemProgress ( TMsvSystemProgress & )

IMPORT_C TIntSystemProgress(TMsvSystemProgress &aOutSysProg)

This call leads to calling SystemProgress() in the server to populate the TMsvSystemProgress structure.

Parameters
aOutSysProgThe TMsvSystemProgress structure to be populated by the server
Return Value
the error of the Extension_ method call