David's Astronomy - Notes 2022-07-07 (S1021A)

Introduction
Apple Inc bought out DarkSky company a couple of years ago, and indicated that DarkSky Site and API would become no longer available at some point. The API has continued to function and provide weather information for the Clair Observatory, but an announcement from Apple on 2022-06-13 stated that from March 31st, 2023 the Dark Sky API will no longer be available and encouraged users to migrate to WeatherKit, a new Apple API available on iOS, iPadOS, macOS, tvOS, and web will that provide access to the new Apple Weather forecast data. DarkSky was free for up to 1000 API calls per day. AppleKit is free for up to 500,000 calls/month with membership of Apple Developer Program.

Details about WeatherKit can be found at https://developer.apple.com/weatherkit/.
and at https://betterprogramming.pub/wwdc22-get-started-with-weatherkit-202794853c01

Proposal
The new WeatherKit API should be investigated and if suitable its use should be built into AstroWeather.

The key components of the program
- Join Apple Developer Program
- Creating and signed a Developer Token for accessing WeatherKit
- Create a working REST API request (with authentication header) that pulls weather data from WeatherKit

Apple Developer Program
Membership of Apple Developer Program requires AppleID with 2-factor authentication turned-on in order to enroll. Membership of AppleKit allows up to 500,000 calls/month free during & after program development

Enable WeatherKit on App ID
In Certificates, Identifiers & Profiles, click Identifiers in the sidebar.

On the top left, click the add button (+), select App IDs, then click Continue.
Register an App ID.
Click the App Services tab.
Select the WeatherKit checkbox.
Click Continue, review the registration information, and click Register.

Note : Remember to also enable WeatherKit in the App Capabilities tab when editing your App ID.

Rest API

DarkSky : https://api.darksky.net/forecast/{secretkey}/{latitude},{longitude}?units=uk2 WeatherKit : GET https://weatherkit.apple.com/api/v1/weather/{language}/{latitude}/{longitude}:

The header of every WeatherKit REST API request requires a signed developer token to identify the authorized ADP member and application or service making the request. WeatherKit only supports developer tokens signed with the ES256 algorithm,

Decoded Token looks like: { "alg": "ES256", "kid": "ABC123DEFG", "id": "DEF123GHIJ.com.example.weatherkit-client" } { "iss": "DEF123GHIJ", "iat": 1437179036, "exp": 1493298100, "sub": "com.example.weatherkit-client" }

Request authentication for WeatherKit REST API : https://developer.apple.com/documentation/weatherkitrestapi/request_authentication_for_weatherkit_rest_apiCreate Token : https://jwt.io/ Pass the developer token as a parameter to the Authorization: Bearer header in each request. Here's an example of a request: curl -v -H 'Authorization: Bearer [developer token]' "https://weatherkit.apple.com/api/v1/availability/{latitude}/{longitude}?country=US"

Looking at VB.Net code examples suggest the following style of coding could be used:

Dim myReq As HttpWebRequest Dim myResp As HttpWebResponse myReq = HttpWebRequest.Create("https://meineURI.net") myReq.Method = "POST" myReq.ContentType = "application/json" myReq.Headers.add("Authorization", "Basic " & Convert.ToBase64String(Encoding.UTF8.GetBytes("username:password"))) Dim myData As String = "yourDataHere" myReq.GetRequestStream.Write(System.Text.Encoding.UTF8.GetBytes(myData), 0, System.Text.Encoding.UTF8.GetBytes(myData).Count) myResp = myReq.GetResponse Dim myreader As New System.IO.StreamReader(myResp.GetResponseStream) Dim myText As String myText = myreader.ReadToEnd

result will be a HttpResponseMessage, and result.Content.ReadAsStringAsync should give you back the JSON data as a string.

Epoch Convertor for getting iat, exp

https://www.epochconverter.com/

Step 1 : Add 2-factor authentication to existing Apple Account
Step 2 : Enroll in Apple Developer Program (annoying to find it cost £79/year to enroll as individual)
Step 3 : Record Team Name and Team ID
Step 4: Create Key (WeatherKit), Create Service ID,
Step 5:    Create JWT Developer Token   ' see C:\Data\Computer\Apple Developer\WeatherKit\JWT_Token_2022-07-19.txt

Step 6:    CreateTWeatherKit class and WeatherKit object in AstroWeather, based on DarkSky class & object
Step 7:   Modify .BuildRequest for WeatherKit Rest API
Step 8:    Modify .SendRequest to pass the JWT developer token as a parameter to the Authorization: Bearer header for request
Step 9: Create btnWeatherKitForecast button and GetWeatherKitForecast() routine
Step 10a: Test GetWeatherKitForecast(). Failing with exception on line myReq.GetRequestStream() :
                   "The request was aborted: Could not create SSL/TLS secure channel."
Step 10b: Add additional code line ServicePointManager.SecurityProtocol = 3072
Step 10c: Retest GetWeatherKitForecast(). Failing with exception : but VS provided no details about the exception
Step 10d: Retest GetWeatherKitForecast(). Failing with exception on line myResp = myReq.GetResponse
                  "The remote server returned an error: (403) Forbidden." (i.e. server refuses to fulfill the request).
Step 10e:   Added additional code lines

Dim postData As String = "" Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData) myReq.ContentLength = byteArray.Length dataStream = myReq.GetRequestStream() dataStream.Write(byteArray, 0, byteArray.Length)

Step 10f: Retest GetWeatherKitForecast(). Failing with exception on line myResp = myReq.GetResponse
                  "The remote server returned an error: (403) Forbidden." (i.e. server refuses to fulfill the request).
Step 10g     Changed code to use
   Dim MyWebClient As New WebClient
   MyWebClient.Headers.Add("Authorization", token)
       ' also tried with "Authorization: Bearer", token   and with "Authorization", "Bearer " + token
   MyWebClient.DownloadFile(Request, JSON_File)

Update 2023-06-01

After investigation and review it was decided not to pursue the WeatherKit API option due to i) difficult & inadequate support/help, ii) cost of annual developer program fee, iii) doesn't replace some useful attributes that were in DarkSky Api, iv) another (free) option, OpenWeather API is available which supports equivalent functionality (though still not as good as DarkSky API).


	Session Aims & Highlights
	- Observing Result - Night Summary Plot - Session Event Log

	Operational Issues
	- Critical Issues (0), Major Issues (0), Minor Issues (2), Small Defects (1), Continuous Improvement (5)

	No images from session [ Local Files >> ]

	Apple WeatherKit (successor to Dark Sky Weather API)

This Web Page:	Notes - Session 1021A (2022-07-07)
Last Updated :	2024-09-25
Site Owner :	David Richards
Home Page :	David's Astronomy Web Site

David's Astronomy Pages
Notes - Session 1021 Attempt (2022-07-07)

Session Aims & Highlights (2022-07-07)

Operational Issues (2022-07-07, S1021A)

Apple WeatherKit (successor to Dark Sky Weather API)

David's Astronomy Pages Notes - Session 1021 Attempt (2022-07-07)

Session Aims & Highlights (2022-07-07)

Operational Issues (2022-07-07, S1021A)

Apple WeatherKit (successor to Dark Sky Weather API)

David's Astronomy Pages
Notes - Session 1021 Attempt (2022-07-07)