TTN V3 Application API Basic Paging and Filtering Client

The next step was to enumerate The Things Network(TTN) Applications so I could connect only to the required Azure IoT hub(s). There would also be a single configuration setting for the client (establish a connection for every TTN application, or don’t establish a connection for any) and this could be overridden with a TTN application attribute

long pageSize = long.Parse(args[3]);
Console.WriteLine($"Page size: {pageSize}");

Console.WriteLine();

using (HttpClient httpClient = new HttpClient())
{
	ApplicationRegistryClient applicationRegistryClient = new ApplicationRegistryClient(baseUrl, httpClient)
	{
		ApiKey = apiKey
	};

	try
	{
		int page = 1;

		string[] fieldMaskPathsApplication = { "attributes" }; // think this is the bare minimum required for integration

		V3Applications applications = await applicationRegistryClient.ListAsync(collaborator, field_mask_paths: fieldMaskPathsApplication, limit: pageSize, page: page);
		while ((applications != null) && (applications.Applications != null)) 
		{
			Console.WriteLine($"Applications:{applications.Applications.Count} Page:{page} Page size:{pageSize}");
			foreach (V3Application application in applications.Applications)
			{
				bool applicationIntegration = ApplicationAzureintegrationDefault;

				Console.WriteLine($"Application ID:{application.Ids.Application_id}");
				if (application.Attributes != null)
				{
					string ApplicationAzureIntegrationValue = string.Empty;
					if (application.Attributes.TryGetValue(ApplicationAzureIntegrationField, out ApplicationAzureIntegrationValue))
					{
						bool.TryParse(ApplicationAzureIntegrationValue, out applicationIntegration);
					}

					if (applicationIntegration)
					{
						Console.WriteLine("  Application attributes");

						foreach (KeyValuePair<string, string> attribute in application.Attributes)
						{
							Console.WriteLine($"   Key: {attribute.Key} Value: {attribute.Value}");
						}
					}
				}
				Console.WriteLine();
			}
			page += 1;
			applications = await applicationRegistryClient.ListAsync(collaborator, field_mask_paths: fieldMaskPathsApplication, limit: pageSize, page: page);
		};
	}
	catch (Exception ex)
	{
		Console.WriteLine(ex.Message);
	}

	Console.WriteLine("Press <enter> to exit");
	Console.ReadLine();
}

I Used the field_mask_paths parameter (don’t need created_at, updated_at, name etc.) to minimise the data returned to my client.

public async System.Threading.Tasks.Task<V3Applications> ListAsync(string collaborator_organization_ids_organization_id = null, string collaborator_user_ids_user_id = null, string collaborator_user_ids_email = null, System.Collections.Generic.IEnumerable<string> field_mask_paths = null, string order = null, long? limit = null, long? page = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
{
   var urlBuilder_ = new System.Text.StringBuilder();
   urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/applications?");
   if (collaborator_organization_ids_organization_id != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("collaborator.organization_ids.organization_id") + "=").Append(System.Uri.EscapeDataString(ConvertToString(collaborator_organization_ids_organization_id, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
   if (collaborator_user_ids_user_id != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("collaborator.user_ids.user_id") + "=").Append(System.Uri.EscapeDataString(ConvertToString(collaborator_user_ids_user_id, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
   if (collaborator_user_ids_email != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("collaborator.user_ids.email") + "=").Append(System.Uri.EscapeDataString(ConvertToString(collaborator_user_ids_email, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
   if (field_mask_paths != null) 
   {
         foreach (var item_ in field_mask_paths) { urlBuilder_.Append(System.Uri.EscapeDataString("field_mask.paths") + "=").Append(System.Uri.EscapeDataString(ConvertToString(item_, System.Globalization.CultureInfo.InvariantCulture))).Append("&"); }
   }
   if (order != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("order") + "=").Append(System.Uri.EscapeDataString(ConvertToString(order, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
   if (limit != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("limit") + "=").Append(System.Uri.EscapeDataString(ConvertToString(limit, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
   if (page != null) 
   {
         urlBuilder_.Append(System.Uri.EscapeDataString("page") + "=").Append(System.Uri.EscapeDataString(ConvertToString(page, System.Globalization.CultureInfo.InvariantCulture))).Append("&");
   }
}

I was hoping that there would be a away to further “shape” the returned data, but in the NSwag generated code the construction of the URL with field_mask_paths, order, limit, and page parameters meant this appears not to be possible.

AdaFruit IO Swagger based desktop HTTP client

Manually building clients for complex RESTful APIs (like AdaFruit.IO) can be a bit tedious so I figured I would try generating a C# http client from the Swagger OpenAPI specification(OAS) metadata.

My initial attempts using the Swagger Editor and NSwag on the AdaFruit.IO public API description didn’t go so well. (for more info see this AdaFruit.IO support forum thread) You may need to manually modify the type of the id field in Data & DataResponse, plus possibly other responses.

After figuring out how to set the API key, my code which uploads simulates three individual feeds and one feed group appears to work reliably.

/*

Copyright ® 2018 Jan devMobile Software, All Rights Reserved

THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
PURPOSE.

http://www.devmobile.co.nz

 */
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using AdaFruit.IO;

namespace AdaFruit.IO
{
   public partial class Client
   {
      string adaFruitIOApiKey = "yourAPIKey";

      partial void PrepareRequest(System.Net.Http.HttpClient client, System.Net.Http.HttpRequestMessage request, string url)
      {
         client.DefaultRequestHeaders.Add("X-AIO-Key", adaFruitIOApiKey);
      }
   }
}

namespace devMobile.IoT.Adafruit.IO.Desktop
{
   class Program
   {
      static void Main(string[] args)
      {
         string userName = "YourUserName"; // This is mixed case & case sensitive
         // The feed group and feed key are forced to lower case by UI
         const string feedGroup = "devduinov2-dot-2";
         const string temperatureKey = "t";
         const double temperatureBase = 20.0;
         const double temperatureRange = 10.0;
         const string humidityKey = "h";
         const double humidityBase = 70.0;
         const double humidityRange = 20.0;
         const string batteryVoltageKey = "v";
         const double batteryVoltageBase = 3.00;
         const double batteryVoltageRange = -1.00;
         TimeSpan feedUpdateDelay = new TimeSpan(0, 0, 15);
         TimeSpan groupUpdateDelay = new TimeSpan(0, 0, 30);
         Random random = new Random();

         while (true)
         {
            Client client = new Client();
            double temperature = temperatureBase + random.NextDouble() * temperatureRange;
            double humidity = humidityBase + random.NextDouble() * humidityRange;
            double batteryVoltage = batteryVoltageBase + random.NextDouble() * batteryVoltageRange;

            Debug.WriteLine("Temperature {0}°C  Humidity {1}%  Battery Voltage {2}V", temperature.ToString("F1"), humidity.ToString("F0"), batteryVoltage.ToString("F2"));

            // First Update the 3 feeds individually
            // Temperature
            Datum temperatureDatum = new Datum()
            {
               Value = temperature.ToString("F1"),
            };
            client.CreateDataAsync(userName, temperatureKey, temperatureDatum).Wait();
            Task.Delay(feedUpdateDelay).Wait();

            // Humidity
            Datum humidityDatum = new Datum()
            {
               Value = humidity.ToString("F0"),
            };
            client.CreateDataAsync(userName, humidityKey, humidityDatum).Wait();
            Task.Delay(feedUpdateDelay).Wait();

            // Battery
            Datum batteryDatum = new Datum()
            {
               Value = batteryVoltage.ToString("F2"),
            };
            client.CreateDataAsync(userName, batteryVoltageKey, batteryDatum).Wait();
            Task.Delay(feedUpdateDelay).Wait();

            // Then update a feed in a group
            Group_feed_data devDuinoData = new Group_feed_data();

            devDuinoData.Feeds.Add(new Anonymous2() { Key = temperatureKey, Value = temperature.ToString("F1")});
            devDuinoData.Feeds.Add(new Anonymous2() { Key = humidityKey, Value = humidity.ToString("F0")});
            devDuinoData.Feeds.Add(new Anonymous2() { Key = batteryVoltageKey, Value = batteryVoltage.ToString("F2")});

            client.CreateGroupDataAsync(userName, feedGroup, devDuinoData).Wait();
            Task.Delay(groupUpdateDelay).Wait();
         }
      }
   }
}