QMailMessageKey Class Reference
[QtMessagingModule, QtPimModule]

Detailed Description

The QMailMessageKey class defines the parameters used for querying a subset of all available messages from the mail store.

A QMailMessageKey is composed of a message property, an optional comparison operator and a comparison value. The QMailMessageKey class is used in conjunction with the QMailStore::queryMessages() and QMailStore::countMessages() functions to filter results which meet the criteria defined by the key.

QMailMessageKeys can be combined using the logical operators (&), (|) and (~) to create more refined queries.

For example:

To create a query for all messages sent from "joe@user.com" with subject "meeting":

    QMailMessageKey subjectKey(QMailMessageKey::Subject,"meeting");
    QMailMessageKey senderKey(QMailMessageKey::Sender,"joe@user.com")
    QMailMessageIdList results = QMailStore::instance()->queryMessages(subjectKey & senderKey);

To query all unread messages from a specific folder:

    QMailMessageIdList unreadMessagesInFolder(const QMailFolderId& folderId)
    {
        QMailMessageKey parentFolderKey(QMailMessageKey::ParentFolderId, folderId);
        QMailMessageKey unreadKey(QMailMessageKey::Status, QMailMessage::Read, QMailDataComparator::Excludes);

        return QMailStore::instance()->queryMessages(parentFolderKey & unreadKey);
    }

See also QMailStore and QMailMessage.

Member Type Documentation

enum QMailMessageKey::Property
flags QMailMessageKey::Properties

This enum type describes the data query properties of a QMailMessage.

The Properties type is a typedef for QFlags<Property>. It stores an OR combination of Property values.

Member Function Documentation

QMailMessageKey::QMailMessageKey ()

Constructor which creates a default-constructed key (one for which isEmpty() returns true) that matches all messages. The logical negation of an empty key also matches all messages.

The result of combining an empty key with a non-empty key is the same as the original non-empty key. This is true regardless of whether the combination is formed by a logical AND or a logical OR operation.

The result of combining two empty keys is an empty key.

QMailMessageKey::QMailMessageKey ( Property p, const QVariant & value, QMailDataComparator::Comparator c = QMailDataComparator::Equal )

Construct a QMailMessageKey which defines a query parameter where QMailMessage::Property p is compared using comparison operator c with a value value.

QMailMessageKey::QMailMessageKey ( const QMailMessageIdList & ids )

Construct a QMailMessageKey which defines a query parameter where messages whose identifiers are in ids are returned.

QMailMessageKey::QMailMessageKey ( const QMailMessageKey & other )

Create a copy of the QMailMessageKey other.

QMailMessageKey::~QMailMessageKey ()   [virtual]

Destroys the QMailMessageKey

void QMailMessageKey::deserialize ( Stream & stream )

Reads the contents of a QMailMessageKey from stream.

bool QMailMessageKey::isEmpty () const

Returns true if the key remains empty after default construction; otherwise returns false.

See also isNonMatching().

bool QMailMessageKey::isNonMatching () const

Returns true if the key is a non-matching key; otherwise returns false.

See also isEmpty().

QMailMessageKey QMailMessageKey::nonMatchingKey ()   [static]

Returns a key that does not match any messages (unlike an empty key).

See also isNonMatching() and isEmpty().

void QMailMessageKey::serialize ( Stream & stream ) const

Writes the contents of a QMailMessageKey to a stream.

QMailMessageKey::operator QVariant () const

Returns the QVariant representation of this QMailMessageKey.

bool QMailMessageKey::operator!= ( const QMailMessageKey & other ) const

Returns true if the value of this key is not the same as the key other. Returns false otherwise.

QMailMessageKey QMailMessageKey::operator& ( const QMailMessageKey & other ) const

Returns a key that is the logical AND of this key and the value of key other.

QMailMessageKey & QMailMessageKey::operator&= ( const QMailMessageKey & other )

Performs a logical AND with this key and the key other and assigns the result to this key.

QMailMessageKey & QMailMessageKey::operator= ( const QMailMessageKey & other )

Assign the value of the QMailMessageKey other to this.

bool QMailMessageKey::operator== ( const QMailMessageKey & other ) const

Returns true if the value of this key is the same as the key other. Returns false otherwise.

QMailMessageKey QMailMessageKey::operator| ( const QMailMessageKey & other ) const

Returns a key that is the logical OR of this key and the value of key other.

QMailMessageKey & QMailMessageKey::operator|= ( const QMailMessageKey & other )

Performs a logical OR with this key and the key other and assigns the result to this key.

QMailMessageKey QMailMessageKey::operator~ () const

Returns a key that is the logical NOT of the value of this key.