Accessing the object/row being edited in Dynamic Data

Question

I'm modifying the "Edit.aspx" default page template used by ASP.NET Dynamic Data and adding some additional controls. I know that I can find the type of object being edited by looking at DetailsDataSource.GetTable().EntityType, but how can I see the actual object itself? Also, can I change the properties of the object and tell the data context to submit those changes?

Answer 1

Hi,

Maybe you have found a solution already, however I'd like to share my expresience on this.

It turned out to be a great pita, but I've managed to obtain the editing row. I had to extract the DetailsDataSource WhereParameters and then create a query in runtime.

The code below works for tables with a single primary key. If you have compound keys, I guess, it will require modifications:

Parameter param = null;
foreach(object item in (DetailsDataSource.WhereParameters[0] as DynamicQueryStringParameter).GetWhereParameters(DetailsDataSource)) {
    param = (Parameter)item;
    break;
}

IQueryable query = DetailsDataSource.GetTable().GetQuery();
ParameterExpression lambdaArgument = Expression.Parameter(query.ElementType, "");
object paramValue = Convert.ChangeType(param.DefaultValue, param.Type);
Expression compareExpr = Expression.Equal(
    Expression.Property(lambdaArgument, param.Name),
    Expression.Constant(paramValue)
);
Expression lambda = Expression.Lambda(compareExpr, lambdaArgument);
Expression filteredQuery = Expression.Call(typeof(Queryable), "Where", new Type[] { query.ElementType }, query.Expression, lambda);
var WANTED = query.Provider.CreateQuery(filteredQuery).Cast<object>().FirstOrDefault<object>();

Answer 2

If it's a DD object you may be able to use FieldTemplateUserControl.FindFieldTemplate(controlId). Then if you need to you can cast it as an ITextControl to manipulate data.

Otherwise, try using this extension method to find the child control:

    public static T FindControl<T>(this Control startingControl, string id) where T : Control
    {
        T found = startingControl.FindControl(id) as T;

        if (found == null)
        {
            found = FindChildControl<T>(startingControl, id);
        }

        return found;
    }