Question

I am data binding to many FormView controls using EF entity instances, but I have to resort to this ridiculous kludge in order to achieve what I want without using EntityDataSource controls:

propertyHeaderSection.DataSource = new List<PropertyDetailsModel> { _propertyDetails };

I suspect I will have to derive my own control from FormView and enable it to accept an almost POCO as a data source. Where do I start?

Answer 1

This is my implementation, sort of the same idea as patmortech, but i also found out that the ValidateDataSource method on the BaseDataBoundControl is what throws the exception at run-time if your datasource isn’t enumerable.

public class CustomFormView : System.Web.UI.WebControls.FormView
    {
        public override object DataSource
        {
            get
            {
                if (!(base.DataSource is IEnumerable))
                    return new[] {base.DataSource};

                return base.DataSource;
            }
            set
            {
                base.DataSource = value;
            }
        }

        // This method complains at run time, if the datasource is not 
        // IListSource, IDataSource or IEnumerbale
        protected override void ValidateDataSource(object dataSource)
        {
            //base.ValidateDataSource(dataSource);
        }
    }

EDIT:

Considering the suggestion, i’ve made some changes to the way i check if the assigned DataSource is enumerable or not. I have also managed to create a sample app (VS 2010 Solution) to demo the changes. The app can be downloaded from http://raghurana.com/blog/wp-content/attachments/FormViewDataProblem.zip

In short this is what i am checking to ensure that the existing datasource can be enumerated already or not:

public static bool CanEnumerate( this object obj )
    {
        if (obj == null) return false;

        Type t = obj.GetType();

        return t.IsArray ||
               t.Implements(typeof (IEnumerable).FullName) ||
               t.Implements(typeof (IListSource).FullName) ||
               t.Implements(typeof (IDataSource).FullName);
    }

Please feel free to suggest more changes, if this isnt quite the desired functionality. Cheers.