public ActionResult Index(int?page)
{
var data = new NorthwindDataContext();
const int pageSize = 3;
// This example passes lambda functions that are called
// when the view passes into the cache-miss part of the template.
// They take advantage to closure scope to use local variables and
// action arguments.
ViewData["page"] = page ?? 1;
ViewData["pageCount"] = ValueHolder.For(() => (data.Employees.Count() + pageSize - 1) / pageSize);
ViewData["employees"] = ValueHolder.For(() =>
{
++Application.FetchEmployeeListCalls;
var employeesInOrder = data.Employees
.OrderBy(x => x.LastName);
return(employeesInOrder
.Skip(((page ?? 1) - 1) * pageSize)
.Take(pageSize));
});
return(View());
}
public ActionResult Show(int id)
{
var productHolder = ValueHolder.For(id, () => {
Response.Write("FETCHING PRODUCT #" + id);
return(_products.SingleOrDefault(p => p.Id == id));
});
return(View(productHolder));
}
public ActionResult Details(int id)
{
// This example uses a method reference instead of a lambda
// with closure variables. The key property is passed along to make this work
ViewData["employee"] = ValueHolder.For <int, Employee>(id, FetchEmployee);
return(View());
}
public void KeyPassesThrough()
{
var calls = 0;
var holder = ValueHolder.For("hello", k =>
{
++calls;
return(new string(k.Reverse().ToArray()));
});
Assert.That(calls, Is.EqualTo(0));
Assert.That(holder.Value, Is.EqualTo("olleh"));
Assert.That(holder.Value, Is.EqualTo("olleh"));
Assert.That(calls, Is.EqualTo(1));
}
public void AcquireMethodShouldBeCalledOnlyOnce()
{
var calls = 0;
var holder = ValueHolder.For(() =>
{
++calls;
return("hello");
});
Assert.That(calls, Is.EqualTo(0));
Assert.That(holder.Value, Is.EqualTo("hello"));
Assert.That(holder.Value, Is.EqualTo("hello"));
Assert.That(calls, Is.EqualTo(1));
}