DTDLParserResolveSample

DTDLParserResolveSample

This sample loads an interface located in a folder structure following the DMR Convention, and enumerates the DTDL elements.

The dtmi:com:example;1 interface uses an additional interface dtmi:com:example:base;1.

Resolving extenal references

To resolve external dependencies, this sample uses the Azure.IoT.ModelsRepository package to resolve interfaces from a local folder. The parser is configured with the ParserDtmiResolverAsync provided in the ModelsRepositoryClientExtensions:

public static async IAsyncEnumerable<string> ParserDtmiResolverAsync(
    this ModelsRepositoryClient client, IReadOnlyCollection<Dtmi> dtmis,
    [EnumeratorCancellation] CancellationToken ct = default)
{
    foreach (var dtmi in dtmis.Select(s => s.AbsoluteUri))
    {
        var result = await client.GetModelAsync(dtmi, ModelDependencyResolution.Disabled, ct);
        yield return result.Content[dtmi];
    }
}

And used from the ModelResolver class:

internal class ModelResolver
{
    public static async Task<DTInterfaceInfo> LoadModelAsync(string dtmi, string dmrBasePath)
    {
        var dmrClient = new ModelsRepositoryClient(new Uri(dmrBasePath));
        var parser = new ModelParser(new ParsingOptions()
        {
            DtmiResolverAsync = dmrClient.ParserDtmiResolverAsync
        });
        Console.WriteLine($"Parser version: {parser.GetType().Assembly.FullName}\n Resolving from: {new DirectoryInfo(dmrBasePath).FullName}");
        var id = new Dtmi(dtmi);
        var dtdl = await dmrClient.GetModelAsync(dtmi, ModelDependencyResolution.Disabled);
        var result = await parser.ParseAsync(dtdl.Content[dtmi]);
        return (DTInterfaceInfo)result[id];
    }
}

Print DTDL Object Model

The DTInfoExtension provides Print methods for each DT*Info type:

var example1 = await ModelResolver.LoadModelAsync("dtmi:com:example;1", basePath);

Console.WriteLine(example1.Print(true));
foreach (var co in example1.Components) 
    Console.WriteLine(
        $"[Co] {co.Value.Name} ({co.Value.Schema.Id}) \n" +
          $"{co.Value.Schema.Print()}\n");