Extending EcsDocumentedit
In instances where using the IDictionary<string, object> Metadata property is not sufficient, or there is a clearer definition of the structure of the ECS-compatible document you would like to index, it is possible to subclass the EcsDocument object and provide your own property definitions.
Through TryRead/ReceiveProperty/WriteAdditionalProperties you can hook into the EcsDocumentJsonConverter and read/write additional properties.
/// <summary>
/// An extended ECS document with an additional property
/// </summary>
[JsonConverter(typeof(EcsDocumentJsonConverterFactory))]
public class MyEcsDocument : EcsDocument
{
[JsonPropertyName("my_root_property"), DataMember(Name = "my_root_property")]
public MyCustomType MyRootProperty { get; set; }
protected override bool TryRead(string propertyName, out Type type)
{
type = propertyName switch
{
"my_root_property" => typeof(MyCustomType),
_ => null
};
return type != null;
}
protected override bool ReceiveProperty(string propertyName, object value) =>
propertyName switch
{
"my_root_property" => null != (MyRootProperty = value as MyCustomType),
_ => false
};
protected override void WriteAdditionalProperties(Action<string, object> write) => write("my_root_property", MyCustomType);
}
The Elastic.CommonSchema.BenchmarkDotNetExporter project takes this approach in the Domain source directory, where the BenchmarkDocument subclasses EcsDocument.