IrcCommandFilter Class Reference

Provides an interface for filtering commands. More...

Inherited by IrcQmlFilter, and IrcQmlFilter.

Public Member Functions
virtual	~IrcCommandFilter ()
virtual bool	commandFilter (IrcCommand *command)=0

Detailed Description

IrcCommandFilter may be used to intercept commands before they get sent further. In order to use IrcCommandFilter, it must be installed via IrcConnection::installCommandFilter().

Command filtering can be useful doing extra tasks for specific type of commands. The following example sends a PING command after each PRIVMSG command. A consequent PONG reply from the server verifies that the PRIVMSG has been also processed.

class CommandVerifier : public QObject,
                        public IrcCommandFilter,
                        public IrcMessageFilter
{
    Q_OBJECT
    Q_INTERFACES(IrcCommandFilter IrcMessageFilter)

public:
    CommandVerifier(IrcConnection* parent) :
        QObject(parent), identifier(0), connection(parent)
    {
        connection->installMessageFilter(this);
        connection->installCommandFilter(this);
    }

    virtual bool commandFilter(IrcCommand* cmd)
    {
        if (cmd->type() == IrcCommand::Message) {
            cmd->setParent(this); // take ownership
            connection->sendCommand(cmd);
            commands.insert(++identifier, cmd);
            connection->sendData("PING communi/" + QByteArray::number(identifier));
            return true;
        }
        return false;
    }

    virtual bool messageFilter(IrcMessage* msg)
    {
        if (msg->type() == IrcMessage::Pong) {
            QString arg = static_cast<IrcPongMessage*>(msg)->argument();
            if (arg.startsWith("communi/")) {
                bool ok = false;
                quint64 id = arg.mid(8).toULongLong(&ok);
                if (ok) {
                    IrcCommand* command = commands.take(id);
                    if (command) {
                        emit verified(command);
                        command->deleteLater();
                        return true;
                    }
                }
            }
        }
        return false;
    }

signals:
    void verified(IrcCommand* cmd);

private:
    quint64 identifier;
    IrcConnection* connection;
    QMap<quint64, IrcCommand*> commands;
};

Note

Notice that it is safe to call IrcConnection::sendCommand() from IrcCommandFilter::commandFilter(). Such commands won't get delivered back to the same filter to avoid recursion.

See also

IrcConnection::installCommandFilter(), IrcMessageFilter

Constructor & Destructor Documentation

IrcCommandFilter::~IrcCommandFilter ( )

inlinevirtual

Destructs the command filter.

The command filter is automatically removed from any connection(s) it is installed on.

See also

IrcConnection::removeCommandFilter()

Member Function Documentation

bool IrcCommandFilter::commandFilter ( IrcCommand *  command )

pure virtual

Reimplement this function to filter commands to installed connections.

Return true to filter the command out, i.e. stop it being handled further; otherwise return false.

See also

IrcConnection::installCommandFilter()