QJsonChannel Core Library

QJsonChannelCore utilises ideas and some implementation details of QJsonRpc implementation. QJsonRpc library has tight integration with communication transport and supports server-to-client messages. So QJsonChannelCore library development was started for resolving these QJsonRpc specialties. In addition, QJsonChannelCore supports JSON Schema Service Descriptor for services and methods discovery.

The main component of QJsonChannelCore is QJsonChannelServiceRepository.

// Build a service repository
QJsonChannelServiceRepository serviceRepository;

You can bind QObjects to the QJsonChannelServiceRepository.

// Build a service object
QSharedPointer<QObject> testService (new TestService());

// Add the service to the repository
serviceRepository.addService ("object", "1.0", "test service", testService);

The main funcuonality of the QJsonChannelServiceRepository is processing QJsonChannelMessage and dispatching them to QJsonChannelService.

// A JSON-RPC request
QJsonChannelMessage request;
request.fromJson (...);

QJsonChannelMessage response = serviceRepository.processMessage (request);

// Get a JSOON-RPC response as a string
QByteArray ... = response.toJson ();

You also can wrap your QObject by QJsonChannelService and work directly with the service:

QJsonChannelService service("myService", "7.5 alpha", "Service answers toy your questions", QSharedPointer<QObject> (new Oracle ()));

// A JSON-RPC request
QJsonChannelMessage request = QJsonChannelMessage::createRequest("question", QJsonValue (42));

QJsonChannelMessage response = service.dispatch (request);

// Get a JSOON-RPC response as integer
int answer = response.result ().toInt ();

Service class

Service object should inherit from QObject

class TestService : public QObject {
	Q_OBJECT
public:

Properties are axposed using Q_PROPERTY

	Q_PROPERTY(float readOnlyProperty READ getReadOnlyProperty);
	Q_PROPERTY(int propertyWithGetterSetter READ getPropertyWithGetterSetter WRITE setPropertyWithGetterSetter);

Both getter and setter functions will be automatically added to a service for properties wich are binded to member:

	Q_PROPERTY(QString property MEMBER property);

Pubblic invokable methods will be exposed with QJsonChannel

	Q_INVOKABLE QString invokableGetter();
	Q_INVOKABLE void invokableSetter(QString p);

Public slots will be exposed as well:

public Q_SLOTS:
	void    slot();
	void    slotWithParams(const QString& first, bool second, double third);
	QString slotWithParamsAndReturnValue(const QString& name);

	void    slotWithVariantParams(const QString& first, bool second, double third, const QVariant& fourth);
	void    slotWithDefaultParameter(const QString& first, const QString& second = QString());

API Documentation

References

• QJsonRpc is a Qt implementation of the JSON-RPC protocol.
• JSON Schema Service Descriptor is simply a JSON Schema with the additional definition for methods.