Consuming JSON from a C# Project

I was thinking about an app that I have wanted to write for a while.  Part of the application uses weather data.  Since I have been using weather underground since forever (Go Blue), that seemed like a natural place to start.  I hopped over to wunderground and sure enough, at the bottom of the page is a link for consuming its API. 

Following the Weather API for Developers – JSON link, I signed up for a free developer account.  Within minutes I got my API key and I was ready to start looking for the data I was interested in for my application. I first went to the documentation page, I started with the current conditions for a city example:

http://api.wunderground.com/api/axxxxxx/conditions/q/CA/San_Francisco.json

I then switched out the state/city criteria with my zip code:

http://api.wunderground.com/api/axxxxxxxx/conditions/q/27519.json

Sure enough, data is getting returned.

Now that I have a source of data, I need a way to consume the data using Visual Studio.  I fired up a Console project just to see how difficult it would be to consume.  I put in a typical webrequest/response:

Uri uri = new Uri(@"http://api.wunderground.com/api/xxxxxxxx/conditions/q/27519.json");
WebRequest webRequest = WebRequest.Create(uri);
WebResponse response = webRequest.GetResponse();
StreamReader streamReader = new StreamReader(response.GetResponseStream());
String responseData = streamReader.ReadToEnd();
Console.WriteLine(responseData);

Sure enough, I am getting the data back:

The next step is to parse this string so I can do something useful with it.  Fortunately, I was coding this solution during a meeting of Cary’s Technology Task Force and I was sitting next to an OData/JSON expert: Ian Cillay .  Ian told me that to parse Json from VS, I needed to get Newtonsoft’s Json.NET framework because MSFT has essentially given up on the parsing and is deferring everything to NewtonSoft.  Once I had that installed via NuGet, I the realized I still needed a class pre-defined to populate from the Json feed.  I fired up a new class with a couple of properties:

public class WeatherData
{
    public String pressue_mb { get; set; }
    public String pressume_in { get; set; }
    public String pressure_trend { get; set; }
    public String relative_humidity { get; set; }
}

I then coded up line to use that Json library to put the data from the response string into an instantiated class:

var outObject = JsonConvert.DeserializeObject<WeatherData>(responseData);

However, when I ran it, nothing was getting populated.

Ian told me that my simple class did not reflect the actual Json.  Stumped (and still hating Json), I then stumbled across this site.  Sure enough  it was like SVCUTIL.exe for Json.  I got the classes created for me

and I then could consume the data like this:

var outObject = JsonConvert.DeserializeObject<RootObject>(responseData);

and the output is

Wahoo!  I will use the Visual Studio’s External Tools Feature to generate classes for me on the fly:

Consuming REST services using Visual Studio 2010

Aetna is dipping its toe into public facing APIs via Carepass.  I signed up for a license and wanted to see how easy it was to consume some HHS drug data found here.  I first checked a GET inside a browser with the following uri:

https://api.carepass.com/hhs-directory-api/drugs/search?name=Cymbalta&apikey=xxx

and I got my results:

I then fired up Visual Studio to see how easy it would be to make a REST WCF call.  Turns out, there is not a way to add-> service reference like you can with SOAP.  This means I am turning back the clock of HttpWebRequest and HttpWebResponse.  Interestingly, there are not very good examples on Stackoverflow and MSDN about consuming non-WCF REST services.  The best example I found was here on Yahoo!

I created a simple ConsoleApp (changed it target runtime from client profile to full .NET 4.0) and launched into code:

static void Main(string[] args)
{
    Uri address = new Uri(@"https://api.carepass.com/hhs-directory-api/drugs/search?name=Cymbalta&apikey=t8bnhyvu9hj7eh4c8tg97jgb");   
    HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;   
    request.Method = "POST";   
    request.ContentType = "application/x-www-form-urlencoded";   

    using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)   
    {   
        StreamReader reader = new StreamReader(response.GetResponseStream());   
        Console.WriteLine(reader.ReadToEnd());   
    }

    Console.ReadKey();
}

Sure enough, it worked like a charm:

So then the next problem – how to I parse this blob of name/value pairs?  And is there hierarchical data in there?  I first thought (hoped) it would be easy – just split by the ‘:’

using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)   
{
    StreamReader reader = new StreamReader(response.GetResponseStream());
    String output = reader.ReadToEnd();
    Console.WriteLine("Response was: " + output.Length);
    String[] splitOutput = output.Split(':');
    foreach (String item in splitOutput)
    {
        Console.WriteLine(item);
    }
}

No dice:

I then switched my delimited to a comma:

That is actually better.  The next thing is seems is to check to see if the comma is inside the double quotes.  I know that the industry is going to REST from SOAP – but this is so much worse than adding a reference in Visual Studio….