Eclipse Milo: How to get the DataType of method argument?

Question

Use eclipse milo to connect a OPCUA server, can use browse to get the method nodes, and then how to get the DataType of method arguments?

Just like: final BrowseDescription browseDesc = new BrowseDescription(nodeIdRoot, BrowseDirection.Forward, Identifiers.References, true, uint(NodeClass.Method.getValue()), uint(BrowseResultMask.All.getValue()));

BrowseResult browseResult = client.browse(browseDesc).get();
for (final ReferenceDescription rf : browseResult.getReferences()) {
    final NodeId childId = rf.getNodeId().local().orElse(null);
    List<Node> nodes = client.getAddressSpace().browse(childId).get();
    for (Node node : nodes) {
        // Now, I get the Node of method.
        // How to get the method arguments data types?
        system.out.println("need Input types {}" /*, InputArgument */);
        system.out.println("will get Output types {}" /*, OutputArgument */);
    }
}

Answer 1

Method Nodes have HasProperty References to Property Nodes named InputArguments and/or OutputArguments, as long as that method receives input or output arguments.

If you read the Value Attribute if these Nodes you'll get an Argument[] describing the arguments (Name, DataType, ValueRank, ArrayDimensions, Description).

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UaMethodNode has getInputArguments and getOutputArguments calls on it that can help as well:

UaMethodNode methodNode = (UaMethodNode) client.getAddressSpace().getNodeInstance(methodId).get();

CompletableFuture<Argument[]> iaf = methodNode
    .getInputArguments()
    .exceptionally(ex -> new Argument[0]);
CompletableFuture<Argument[]> oaf = methodNode
    .getOutputArguments()
    .exceptionally(ex -> new Argument[0]);

iaf.thenAcceptBoth(oaf, (ia, oa) -> {
    System.out.println("inputArgs: " + Arrays.toString(ia));
    System.out.println("outputArgs: " + Arrays.toString(oa));
});