Eric lippert - Amazon Web Services

Media Formatters are the extension points that allow us to plug
in our own Formatter and thus help our Service support more
Content Types.
Defining the Premise
Today we will see how we can build a Web Service that returns
Appointments in a rudimentary Timekeeping application that
maintains ‘Timecards’.
On top of the Service, we will have a Single Page application
that uses Knockout JS to render basic CRUD screens for
Timecards. We will also create a Media Formatter that formats
these ‘Timecards’ into the VCalendar format so that they can be
downloaded and imported into our Calendaring tools like
Outlook etc.
Building a ‘Time Card’
Service
We will start off by creating a new MVC 4 project in Visual Studio
and call it TimeKeepr. From the templates list, we select the
‘Web API’ template to get started.
First up, let’s build the model and the controller.
The Model and (Web) API
Controller
Our Model is very simple. It has the following properties. As we
can see, it’s a bare-bones definition of a Task, it simply maintains
Summary, Description, StartDate and EndDate.
public class TimeCard
{
public int Id { get; set; }
public string Summary { get; set; }
public string Description { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public string Status { get; set; }
}
Once the model is added, we build the app, and then add a
TimeCardController with the following settings. As you can see,
we are creating API controllers as opposed to MVC Controllers so
no views are going to be generated.
The DBContext that is created by the scaffold pretty much takes
care of the database persistence. Today we will cut some ‘pattern’
corners and leave the DBContext instantiation in the controller
itself. For a production system, it should be a part of the
Repository and we should be injecting repository instances into
the controller.
The View using
Knockout JS
We will build a single page View with Add and Edit functionality.
The view will use the Knockout JS library to implement two way
data-binding. This will give us a nice and responsive UI. We will
post data back to the server using Ajax. We will also use a plugin
by Ryan Niemeyer that will help us control Knockout’s two way
data-binding by giving us options to either commit or roll-back
any changes.
Setting up Dependencies
We’ll update our jQuery and KO dependencies from the Nuget
Package Manager using the following commands
PM> update-package jquery –version 1.9.1
PM> update-package knockoutjs
Next we’ll add a JS called knockout.protectedObservable.js and
add the following script by Ryan Niemeyer.
// Source-Ryan Niemeyer’s JS Fiddle at http://jsfiddle.
net/rniemeyer/X9rRa/
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