## MVC Form Helper

Seth Juarez7/23/2008

## Moving away from ASP 3.0 Request.Form(" ...

As mentioned in my previous post, I wanted to find a way to auto-populate and entity object from the Request.Form collection. I also wanted (as an aside) to see if the grid still worked on MVC Preview 4 (it does). Here is the code:

public static T Request<T>(this Controller controller) where T : class, new()
{
T o = new T();
var request = controller.Request;
foreach (var property in typeof(T).GetProperties())
{
// Check if the object has the appropriate property
var q = (request.Form.AllKeys
.Where<string>(s => s.ToLower() == property.Name.ToLower()))
.ToList<string>();

// if more than one... ignore
if(q.Count == 1)
{
string datum = request.Form[q[0]];
if (property.PropertyType == typeof(string))
property.SetValue(o, datum, null);
else
property.SetValue(o,
Convert.ChangeType(datum, property.PropertyType),
null);
}
}

return o;
}


Notice that this is not an extension on the HtmlHelper since this will only be used inside the controller (hence a controller extension method). Here is how it is used:

Student s = this.Request<Student>();


Now for the explanation! The constraints on T (line 1, the where part) say that T must be a reference type and have a parameter-less constructor. I guess it doesn't have to have a parameter-less constructor but I thought it would be a pain to find out which request key matched up with which parameter in the constructor. I also thought that Entity classes should be POCO objects so they would naturally have an empty constructor. Some screenshots:

Before:

After:

## The Grid

I am continuing to work on the grid (this was a part of it). I just haven't gotten around to implementing the next thing all the way. The goal again was to have more control over how the grid should be rendered. I am borrowing some of the ideas from the MVCContrib grid but simplifying it a whole lot (for simple users like myself)

## MVC Preview 4

I uninstalled preview 3 and then installed preview 4 and shortly after found that VS could not open my preview 3 stuff. Instead of rigging it, I just re-created the MVC part. The Controls assembly (the one with the grid) worked perfectly after correcting the references to the MVC dll's.