Example 3: Connections to Remote Nodes using a Registry | Qt Remote Objects 6.8.0
Description: Describes how the Qt Remote Objects registry establishes connections between nodes. This example illustrates the use of a Registry to build the node topology. For simple networks, we use a QUrl to create a direct connection between two nodes. For complex networks, we use a registry, where you use a different QUrl to point both the host and replica nodes to the registry. For only two nodes, the benefits of using a registry are minimal. But, as the network grows, using a registry means that all nodes only need to connect to the registry via a single QUrl. In comparison, with direct connections, nodes would have to maintain a list of QUrls for every single node that they link to.

- Qt 6.8
- Qt Remote Objects
- Example 3: Connections to Remote Nodes using a Registry
- Qt 6.8.0 Reference Documentation

# Example 3: Connections to Remote Nodes using a Registry

### Set up the Source

The `simpleswitch.h` and `simpleswitch.cpp` sources from Example can be used without modification. The difference is in the way a host node is created and connected to the registry:

`main.cpp`

     #include <QCoreApplication>
     #include "simpleswitch.h"

     int main(int argc, char *argv[])
     {
         QCoreApplication a(argc, argv);

         SimpleSwitch srcSwitch; // create SimpleSwitch

         // Create node that hosts registry:
         QRemoteObjectRegistryHost regNode(QUrl(QStringLiteral("local:registry")));

         // Create node that will host source and connect to registry:
         QRemoteObjectHost srcNode(QUrl(QStringLiteral("local:replica")),
                                   QUrl(QStringLiteral("local:registry")));
         // Note, you can add srcSwitch directly to regNode if desired.
         // We use two Nodes here, as the regNode could easily be in a third process.

         srcNode.enableRemoting(&srcSwitch); // enable remoting of source object

         return a.exec();
     }

### Set up the Replica

The requestor object used for this example is the dynamic replica client discussed in Example 2.

The only modification is in `main.cpp`: a Registry node is created to acquire a Replica:

         QRemoteObjectNode repNode(QUrl(QStringLiteral("local:registry")));

When run together with the source-side example, the output is identical to Example 1.