server_instantiation.cpp

#include <open62541pp/node.hpp>
#include <open62541pp/server.hpp>
 
int main() {
    opcua::Server server;
 
    // Create object types `MammalType` and `DogType`:
    // (ObjectType) BaseObjectType
    // └─ (ObjectType) MammalType
    //    ├─ (Variable) Age
    //    └─ (ObjectType) DogType
    //       └─ (Variable) Name
    opcua::Node nodeBaseObjectType{server, opcua::ObjectTypeId::BaseObjectType};
    auto nodeMammalType = nodeBaseObjectType.addObjectType(
        {1, 10000},
        "MammalType",
        opcua::ObjectTypeAttributes{}
            .setDisplayName({"en-US", "MammalType"})
            .setDescription({"en-US", "A mammal"})
    );
 
    nodeMammalType
        .addVariable(
            {1, 10001},
            "Age",
            opcua::VariableAttributes{}
                .setDisplayName({"en-US", "Age"})
                .setDescription({"en-US", "This mammals age in months"})
                .setValue(opcua::Variant{0U})  // default age
        )
        .addModellingRule(opcua::ModellingRule::Mandatory);  // create on new instance
 
    auto nodeDogType = nodeMammalType.addObjectType(
        {1, 10002},
        "DogType",
        opcua::ObjectTypeAttributes{}
            .setDisplayName({"en-US", "DogType"})
            .setDescription({"en-US", "A dog, subtype of mammal"})
    );
 
    nodeDogType
        .addVariable(
            {1, 10003},
            "Name",
            opcua::VariableAttributes{}
                .setDisplayName({"en-US", "Name"})
                .setDescription({"en-US", "This dogs name"})
                .setValue(opcua::Variant{"unnamed dog"})  // default name
        )
        .addModellingRule(opcua::ModellingRule::Mandatory);  // create on new instance
 
    // Instantiate a dog named Bello:
    // (Object) Objects
    // └─ (Object) Bello <DogType>
    //    ├─ (Variable) Age
    //    └─ (Variable) Name
    opcua::Node nodeObjects{server, opcua::ObjectId::ObjectsFolder};
    auto nodeBello = nodeObjects.addObject(
        {1, 20000},
        "Bello",
        opcua::ObjectAttributes{}
            .setDisplayName({"en-US", "Bello"})
            .setDescription({"en-US", "A dog named Bello"}),
        nodeDogType.id()
    );
 
    // Set variables Age and Name
    nodeBello.browseChild({{1, "Age"}}).writeValue(opcua::Variant{3U});
    nodeBello.browseChild({{1, "Name"}}).writeValue(opcua::Variant{"Bello"});
 
    server.run();
}