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EndpointDiscovery QML Type

Provides information about available endpoints on a server. More...

Import Statement: import QtOpcUa
Since: QtOpcUa 5.13

Properties

Signals

Methods

  • EndpointDescription at(index)

Detailed Description

Allows to fetch and access information about available endpoints on a server.

QtOpcUa.Connection {
    id: connection
    backend: availableBackends[0]
    defaultConnection: true
}

QtOpcUa.ServerDiscovery {
    discoveryUrl: "opc.tcp://127.0.0.1:43344"
    onServersChanged: {
        if (status.isGood) {
            if (status.status == QtOpcUa.Status.GoodCompletesAsynchronusly)
                return; // wait until finished
            if (count > 0) {
                // choose right server
                endpointDiscovery.serverUrl = at(0).discoveryUrls[0];
                console.log("Using server URL:", endpointDiscovery.serverUrl);
            } else {
                // no servers retrieved
            }
        } else {
            // Fetching servers failed
            console.log("Error fetching server:", servers.status.status);
        }
    }
}

QtOpcUa.EndpointDiscovery {
    id: endpointDiscovery
    onEndpointsChanged: {
        if (status.isGood) {
            if (status.status == QtOpcUa.Status.GoodCompletesAsynchronusly)
                return; // wait until finished
            if (count > 0) {
                // choose right endpoint
                console.log("Using endpoint", at(0).endpointUrl, at(0).securityPolicy);
                connection.connectToEndpoint(at(0));
            } else {
                // no endpoints retrieved
            }
        } else {
            // Fetching endpoints failed
            console.log("Error fetching endpoints:", status.status);
        }
    }
}

Property Documentation

connection : Connection

The connection to be used for requesting information.

If this property is not set, the default connection will be used, if any.

See also Connection and Connection::defaultConnection.


count : int

Current number of endpoints in this element. Before using any data from an endpoint discovery, you should check status if the information was successfully retrieved.

See also status and Status.


serverUrl : string

Discovery URL of the server to fetch the endpoints from. Every time the URL is changed, a request to the given server is started.

When starting the request, the list of available endpoints is cleared and the status is set to Status.GoodCompletesAsynchronously. Once the request is finished, status changes.

Make sure to check status before accessing the list of endpoints.

See also endpointsChanged.


status : Status

The current status of this element. In case the last retrieval of endpoints was successful, the status is Status.Good.

if (endpoints.status.isGood) {
    // do something
} else {
    // handle error
}

See also Status.


Signal Documentation

endpointsChanged()

Emitted when a retrieval request started, finished or failed. In a called function, you should first check the status of the object. If the status is Status.GoodCompletesAsynchronously, the request is still running. If the status is Status.Good, the request has finished and the endpoint descriptions can be read. If the status is not good, an error happened and status contains the returned error code.

onEndpointsChanged: {
        if (endpoints.status.isGood) {
            if (endpoints.status.status == QtOpcua.Status.GoodCompletesAsynchronusly)
                return; // wait until finished
            if (endpoints.count > 0) {
                var endpointUrl = endpoints.at(0).endpointUrl();
                console.log(endpointUrl);
            }
        } else {
            // handle error
        }
}

Note: The corresponding handler is onEndpointsChanged.

See also status, count, at, Status, and EndpointDescription.


Method Documentation

EndpointDescription at(index)

Returns the endpoint description at given index. In case there are no endpoints available or the index is invalid, an invalid endpoint description is returned. Before using any data from this, you should check status if retrieval of the information was successful.

if (endpoints.status.isGood) {
    if (endpoints.count > 0)
        var endpointUrl = endpoints.at(0).endpointUrl();
        console.log(endpointUrl);
} else {
    // handle error
}

See also count, status, and EndpointDescription.


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