Making object models in solution based on third party ElasticSearch solution

Question

When you deal with JSON, it's really easy to make C# models. You either Paste special in Visual Studio, or you use one of the many available tools online.

ElasticSearch responses obviously are JSON, meaning, if you can get the responding JSON, you're good to go. However, if you just have a connection-string and simply want to "map" all the ElasticSearch objects into your C# code - how do you do it?

My question:

Is there a way to see all fields/data in an ElasticSearch instance, and then easily get the JSON, so you can get strongly typed models?

Answer 1

You can query elasticsearch for mappings. Mapping will contain all information you need to build model in C# (but you will still have to build it by hand I think). Example using database from your previous question:

var settings = new ConnectionSettings(new Uri("http://distribution.virk.dk/cvr-permanent"));
var client = new ElasticClient(settings);
// get mappings for all indexes and types
var mappings = client.GetMapping<JObject>(c => c.AllIndices().AllTypes());
foreach (var indexMapping in mappings.Indices) {
    Console.WriteLine($"Index {indexMapping.Key.Name}"); // index name
    foreach (var typeMapping in indexMapping.Value.Mappings) {
        Console.WriteLine($"Type {typeMapping.Key.Name}"); // type name
        foreach (var property in typeMapping.Value.Properties) { 
            // property name and type. There might be more useful info, check other properties of `typeMapping`
            Console.WriteLine(property.Key.Name + ": " + property.Value.Type);
            // some properties are themselves objects, so you need to go deeper
            var subProperties = (property.Value as ObjectProperty)?.Properties;
            if (subProperties != null) {
                // here you can build recursive function to get also sub-properties
            }
        }
    }
}