Akonadi::TransactionSequence Class Reference

#include <transactionsequence.h>

Inheritance diagram for Akonadi::TransactionSequence:

Public Member Functions
	TransactionSequence (QObject *parent=0)
	~TransactionSequence ()
void	commit ()
void	rollback ()
void	setAutomaticCommittingEnabled (bool enable)
void	setIgnoreJobFailure (KJob *job)
Public Member Functions inherited from Akonadi::Job
	Job (QObject *parent=0)
virtual	~Job ()
virtual QString	errorString () const
void	start ()

Protected Slots
void	slotResult (KJob *job)
Protected Slots inherited from Akonadi::Job
virtual void	slotResult (KJob *job)

Protected Member Functions
bool	addSubjob (KJob *job)
void	doStart ()
Protected Member Functions inherited from Akonadi::Job
virtual void	doHandleResponse (const QByteArray &tag, const QByteArray &data)
virtual bool	doKill ()
void	emitWriteFinished ()
virtual bool	removeSubjob (KJob *job)

Additional Inherited Members
Public Types inherited from Akonadi::Job
enum	Error {   ConnectionFailed = UserDefinedError, ProtocolVersionMismatch, UserCanceled, Unknown,   UserError = UserDefinedError + 42 }
typedef QList< Job * >	List
Signals inherited from Akonadi::Job
void	aboutToStart (Akonadi::Job *job)
void	writeFinished (Akonadi::Job *job)

Detailed Description

Base class for jobs that need to run a sequence of sub-jobs in a transaction.

As soon as the first subjob is added, the transaction is started. As soon as the last subjob has successfully finished, the transaction is committed. If any subjob fails, the transaction is rolled back.

Alternatively, a TransactionSequence object can be used as a parent object for a set of jobs to achieve the same behaviour without subclassing.

Example:

// Delete a couple of items inside a transaction
Akonadi::TransactionSequence *transaction = new Akonadi::TransactionSequence;
connect( transaction, SIGNAL( result( KJob* ) ), SLOT( transactionFinished( KJob* ) ) );

const Akonadi::Item::List items = ...

foreach ( const Akonadi::Item &item, items ) {
  new Akonadi::ItemDeleteJob( item, transaction );
}

...

MyClass::transactionFinished( KJob *job )
{
  if ( job->error() )
    qDebug() << "Error occurred";
  else
    qDebug() << "Items deleted successfully";
}

Author

Volker Krause vkrau.nosp@m.se@k.nosp@m.de.or.nosp@m.g

Definition at line 69 of file transactionsequence.h.

Constructor & Destructor Documentation

TransactionSequence::TransactionSequence ( QObject *  parent = 0 )

explicit

Creates a new transaction sequence.

Parameters

parent

The parent object.

Definition at line 75 of file transactionsequence.cpp.

TransactionSequence::~TransactionSequence

(

)

Destroys the transaction sequence.

Definition at line 80 of file transactionsequence.cpp.

Member Function Documentation

bool TransactionSequence::addSubjob ( KJob *  job )

protectedvirtual

Adds the given job as a subjob to this job.

This method is automatically called if you construct a job using another job as parent object. The base implementation does the necessary setup to share the network connection with the backend.

Parameters

job	The new subjob.

Reimplemented from Akonadi::Job.

Definition at line 84 of file transactionsequence.cpp.

void TransactionSequence::commit

(

)

Commits the transaction as soon as all pending sub-jobs finished successfully.

Definition at line 144 of file transactionsequence.cpp.

void TransactionSequence::doStart ( )

protectedvirtual

This method must be reimplemented in the concrete jobs.

It will be called after the job has been started and a connection to the Akonadi backend has been established.

Implements Akonadi::Job.

Definition at line 185 of file transactionsequence.cpp.

void TransactionSequence::rollback

(

)

Rolls back the current transaction as soon as possible.

You only need to call this method when you want to roll back due to external reasons (e.g. user cancellation), the transaction is automatically rolled back if one of its subjobs fails.

Since

4.5

Definition at line 203 of file transactionsequence.cpp.

void TransactionSequence::setAutomaticCommittingEnabled

(

bool

enable

)

Disable automatic committing.

Use this when you want to add jobs to this sequence after execution has been started, usually that is outside of the constructor or the method that creates this transaction sequence.

Note

Calling this method after execution of this job has been started has no effect.

Parameters

enable

true to enable autocommitting (default), false to disable it

Since

4.5

Definition at line 197 of file transactionsequence.cpp.

void TransactionSequence::setIgnoreJobFailure

(

KJob *

job

)

Sets which job of the sequence might fail without rolling back the complete transaction.

Parameters

job	a job to ignore errors from

Since

4.5

Definition at line 175 of file transactionsequence.cpp.

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The documentation for this class was generated from the following files:

• transactionsequence.h
• transactionsequence.cpp