Yahoo! Web Services Request and AjaxPro JSON Parser

Yesterday night I build an example on how to use Yahoo! Web Services
with the AjaxPro JSON parser. The example will call a Yahoo! Web
Service with output type set to JSON (see

http://developer.yahoo.com/common/json.html

). The response will be
deserialized to an .NET structure using the AjaxPro JSON parser (from
the stand-alone version or the build-in parser in Ajax.NET
Professional).

First of all I have to get the response from the Web Service using the
WebRequest class:

string query = "Madonna"; // demo search for "Madonna"
int count = 5;

WebRequest request = WebRequest.Create(
"

http://api.search.yahoo.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&query

="
+
query + "&results=" + count + "&output=json"
);

request.Credentials = CredentialCache.DefaultCredentials;

HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);

string responseFromServer = reader.ReadToEnd();

reader.Close();
dataStream.Close();
response.Close();

Now, I have to deserialize the JSON response string to an .NET data
type. I can simply generate an IJavaScriptObject from the JSON string
and go to all properties. But today I'd like to get a real .NET class.
I had a look on the result XML schema and build my own structures that
will represent the results from the Yahoo! Web Service:

struct YahooResponse
{
public YahooResultSet ResultSet;
}

struct YahooResultSet
{
public string totalResultsAvailable;
public int totalResultsReturned;
public int firstResultPosition;
public YahooResult

Result;
}

struct YahooResult
{
public string Title;
public string Summary;
public string Url;
public string ClickUrl;
public string RefererUrl;
public string FileSize;
public string FileFormat;
public string Height;
public string Width;
public YahooThumbnail Thumbnail;
}

struct YahooThumbnail
{
public string Url;
public string Height;
public string Width;
}

The next line will create a YahooResponse object from the JSON string...

YahooResponse r =
JavaScriptDeserializer.DeserializeFromJson<YahooResponse>(responseFromServer);

...and allowes me to go through the result set with .NET data types.
What do you think?

Console.WriteLine(r.ResultSet.totalResultsAvailable + " Results");

foreach (YahooResult s in r.ResultSet.Result)
{
Console.WriteLine("\t ** " + s.Title);
Console.WriteLine("\t format: " + s.FileFormat);
Console.WriteLine("\t size: " + s.Width + " x " + s.Height);
}

Note: Did you noticed the generic DeserializeFromJson method which is
new to the current release?
--
Best regards | Schöne Grüße
Michael

Microsoft MVP - Most Valuable Professional
Microsoft MCAD - Certified Application Developer

http://weblogs.asp.net/mschwarz

http://www.schwarz-interactive.de

/
mailto:info

--

Best regards | Schöne Grüße Michael

Microsoft MVP - Most Valuable Professional Microsoft MCAD - Certified Application Developer

http://weblogs.asp.net/mschwarz

http://www.schwarz-interactive.de

/
mailto:info