Better example?

[HenrikDK]

Hi

I'm evaluating using Flipt.io for use with my C# apps, while im somewhat dissapointed that a C# sdk didn't get first billing like python or java. I'm glad to see that a Grpc SDK is underway :)

I am confused by the example provided though:

using Grpc.Net.Client;
using Flipt;

var channel = GrpcChannel.ForAddress("http://localhost:9000");
var client = new Flipt.Flipt.FliptClient(channel);
var result = client.ListFlags(new Flipt.ListFlagRequest());

System.Console.WriteLine("Available Flags:");
foreach (var flag in result.Flags)
{
    System.Console.WriteLine(flag.Key);
}

It hard to get an idea of how the client works in a real usecase, as a typical client isn't interested in listing all flags and iterating through them?

Normally you would evaluate a specific flag that you address by name, and maybe provide other variables.

I had expected an example like the python one here https://github.com/flipt-io/flipt-server-sdks/tree/main/flipt-python

from flipt import FliptClient
from flipt.evaluation import BatchEvaluationRequest, EvaluationRequest

fliptClient = FliptClient()

v = fliptClient.evaluation.variant(
    EvaluationRequest(
        namespace_key="default",
        flag_key="flagll",
        entity_id="entity",
        context={"fizz": "buzz"},
    )
)

print(v)

[GeorgeMac]

Hey @HenrikDK 👋 Thanks for raising the issue and apologies for the lack of clarity in our docs. We lack any C# experience on the Flipt team, so could do with any and all help in getting something correct together.

I've just taken a stab at an alternative, which is more inline with our Python example you linked here.
What do you think of it:

using Grpc.Net.Client;
using Flipt;

namespace dotnetexperiment;

class Program
{
    static void Main(string[] args)
    {
        var channel = GrpcChannel.ForAddress("http://localhost:9000");
        var client = new Flipt.Evaluation.EvaluationService.EvaluationServiceClient(channel);
        var request = new Flipt.Evaluation.EvaluationRequest {
            NamespaceKey = "default",
            FlagKey      = "flag",
            EntityId     = "entity",
        };
        request.Context.Add("fizz", "buzz");

        System.Console.WriteLine(client.Variant(request));
    }
}

I tested it locally and it evaluated as expected. If you think it fits the bill, I can get the docs and example updated.

[HenrikDK]

That looks better, much clearer :) 👍 from here.

It could also be an idea to very explicitly illustrate usage in application code, ie how you fork your code based on a usage flag:

Something like this.

using Grpc.Net.Client;
using Flipt;

var channel = GrpcChannel.ForAddress("http://localhost:9000");
var flipt= new Flipt.Evaluation.EvaluationService.EvaluationServiceClient(channel);
var newHotFeature = new Flipt.Evaluation.EvaluationRequest {
            NamespaceKey = "default",
            FlagKey      = "NewHotFeature",
            EntityId     = "entity",
};
newHotFeature.Context.Add("fizz", "buzz");


if(flipt.Variant(newHotFeature).Match)
{
  //new code
}
else
{
  //old code
}

While not quite as elegant as other feature toggle solutions out there, it's not unworkable :)

[markphelps]

Thanks for the feedback and for raising this issue @HenrikDK 🙌🏻

We will update the readme now!

Re @GeorgeMac 's comment:

We lack any C# experience on the Flipt team, so could do with any and all help in getting something correct together.

If you can help contribute a REST evaluation SDK or potentially help us get started that would be amazing! As we have done very little C# dev on the team and would want someone with greater C# expertise to make it idiomatic

See: flipt-io/flipt-server-sdks#86