Eric lippert - Amazon Web Services

public override bool CanWriteType(Type type)
{
if (type == typeof(TimeCard))
{
return true;
}
}
Next comes the crux of the formatter - the WriteToStream method.
We cast the incoming object into a TimeCard and call the
WriteVCalendar method that writes to the stream buffer.
public override void WriteToStream(Type type, object
value, Stream stream, System.Net.Http.HttpContent
content) {
using (var writer = new StreamWriter(stream))
{
var timeCard = value as TimeCard;
if (timeCard == null)
{
throw new InvalidOperationException(“Cannot serialize
type”);
}
WriteVCalendar(timeCard, writer);
}
stream.Close();
}
As we can see below, VCalendar items are simply formatted text
and we use the data in our TimeCard to create the appropriate
string for the VCalendar.
private void WriteVCalendar(TimeCard contactModel,
StreamWriter writer) {
var buffer = new StringBuilder();
buffer.AppendLine(“BEGIN:VCALENDAR”);
buffer.AppendLine(“VERSION:2.0”);
buffer.AppendLine(“PRODID:-//DNC/DEMOCAL//NONSGML v1.0//
EN”);
buffer.AppendLine(“BEGIN:VEVENT”);
buffer.AppendLine(“UID:suprotimagarwal@example.com”);
buffer.AppendFormat(“STATUS:{0}\r\n”, contactModel.
Status);
buffer.AppendFormat(“DTSTART:{0}Z\r\n”, (contactModel.
StartDate.ToFileTimeUtc().ToString()));
buffer.AppendFormat(“DTEND:{0}Z\r\n”, (contactModel.
EndDate.ToFileTime().ToString()));
buffer.AppendFormat(“SUMMARY:{0}\r\n”, contactModel.
Summary);
buffer.AppendFormat(“DESCRIPTION:{0}\r\n”, contactModel.
Description);
buffer.AppendLine(“END:VEVENT”);
buffer.AppendLine(“END:VCALENDAR”);
writer.Write(buffer);
}
Associating Custom Formatter
in our WebAPI Application
This is a single line of configuration in code. In the
App_Start\WebApiConfig.cs, we add the following in the last line
of the Register method
config.Formatters.Add(new VCalendarMediaTypeFormatter());
If you don’t have the WebApiConfig.cs, you can use
GlobalConfiguration.Configuration.Formatters.Add(new
VCalendarMediaTypeFormatter());
That’s it we are done.
Testing the Custom Formatter
Out
Our Formatter is all set, how can we test this Well we can test
it using Fiddler by creating a new Request as follows. In the
Composer Tab, we set the Request Type to a GET put the following
headers
Host: localhost:54882
User-Agent: Fiddler
Accept: text/calendar
Accept-Encoding: text
Content-Type: text/calendar
Connection: keep-alive
We post it to the URL
http://localhost:54882/api/TimeCardId=1
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