/// <summary>
/// This method creates the connection the webApi.
/// We send a request with several parameters which indicates:
/// appid: unique key
/// q: name of the city
/// lang: language(da)
/// units: type of unit system is returned(metric)
/// We make an instance of MemoryStream,
/// this is the object which contains the return of our request as a collection of bytes.
/// Create an abstract variable webReq which holds the actual request.
/// The request has to be made as a WebRequest which has to be casted to a HTTPWebRequest, this means we by force transform.
/// We do this as we can't make a HTTPWebRequest with the parameters that are available,
/// but as there is a overloaded constructor in the class which can convert a WebRequest into a HTTPWebRequest instance
/// we obtain that the communication between the application and the WEB API is via the HTTP protocol
/// The actual communication with the WEB API is wrapped in a "using",
/// as we want the actual connection to be closed properly after use without having to write to much code,
/// as using and GarbageCollector will do this for us.
/// In the first using we start the request, as we are communicating with and external device
/// we use await to imply that this part can be executed asynchronized.
/// This means that if the WEB API doesnt answer at once, the application will give the right to execute new actions,
/// to a new thread and as soon as the WEB API begins to answer,
/// this method will once again recieve the highed priority to execute actions.
/// the instance webReq has to be translated to a WebResponse, which is the object that holds the connection to the WEB API.
/// The instance response has to be translated to a Stream which,
/// handles the data packages which are recieved via the HTTP protocol.
/// The instance of our Stream(responseStream) also uses await as there can't be transfered data to our content
/// of datatype MemoryStream before all packages have been received from the WEB API
/// because content is not completely build until all packages are recieved. This is why we use async,
/// so the program doesnt freeze trying to deliver content to the gui, when not all data has been recieved.
/// When all packages are recieved we convert them to a MemoryStream.
/// Now we have to ensure that the text we recieve as answer is readable by our application.
/// Therefore we make an encoding to UTF8 which ensures all nordical characters are recognized and showable.
/// Now we have a dataset which can be be converted to our own simple datatype classCityWeather via JsonConvert,
/// here we imply which class we want to convert to and a indication of the source to the data which
/// have to be implemented in the datatype.
/// Then we return an instance of ClassCityWeather which now contains all the data we have recieved from the Web API.
/// </summary>
/// <param name="inCityName">string</param>
/// <returns>Task<ClassCityWeather></returns>
public async Task <ClassCityWeather> GetDataFromWeatherOrg(string inCityName)
{
ClassCityWeather classCityWeather = new ClassCityWeather();
var content = new MemoryStream();
var webReq = (HttpWebRequest)WebRequest.Create($"https://api.openweathermap.org/data/2.5/weather?q={inCityName}&appid=2beb42488b790cae931e8106c7a52c5e&lang=da&units=metric");
using (WebResponse response = await webReq.GetResponseAsync())
{
using (Stream responseStream = response.GetResponseStream())
{
await responseStream.CopyToAsync(content);
}
}
string strRes = System.Text.Encoding.UTF8.GetString(content.ToArray()); // content is byte, if we make them into an array we can use encoding to make a readable string
classCityWeather = JsonConvert.DeserializeObject <ClassCityWeather>(strRes); // JsonConvert class has a method called Deserialze object,
// the method needs an indication of the object it needs to build(ClassCityWeather)
// and a parameter which here is a string that contains the data recieved fromt the api as a string in Json format
return(classCityWeather);
}
public ClassBIZ()
{
cityWeather = new ClassCityWeather();
cityName = "";
}
