DynamicData - How can I show the child count in the Children.ascx.cs FieldTemplate?

Question

MS DynamicData's Children.ascx.cs file has a Page_Load method that returns a hyperlink which says "View Children". I want to append the number of children to the end of the hyperlink text. Below is my attempt. How can I make the hyperlink say "View Children - # entries" ?

protected void Page_Load(object sender, EventArgs e)
{
    HyperLink1.Text = "View " + ChildrenColumn.ChildTable.DisplayName;

    //The following code gives the total entries.
    //How do I get the number of children only?
    //int entries = 0;
    //foreach (var entry in ChildrenColumn.ChildTable.GetQuery()) { entries++; }
    //string entryText = (entries == 1) ? "entry" : "entries";
    //HyperLink1.Text= HyperLink1.Text + " " + entries + " " + entryText;
}

Answer 1

Actually it is not that hard. You can add the following Method to your Children.ascx.cs file:

    protected override void OnDataBinding(EventArgs e)
    {
        base.OnDataBinding(e);

        object entity;
        ICustomTypeDescriptor rowDescriptor = Row as ICustomTypeDescriptor;
        if (rowDescriptor != null)
        {
            // Get the real entity from the wrapper
            entity = rowDescriptor.GetPropertyOwner(null);
        }
        else
        {
            entity = Row;
        }

        // Get the collection and make sure it's loaded
        RelatedEnd entityCollection = Column.EntityTypeProperty.GetValue(entity, null) as RelatedEnd;
        if (entityCollection == null)
        {
            throw new InvalidOperationException(String.Format("The Children template does not support the collection type of the '{0}' column on the '{1}' table.", Column.Name, Table.Name));
        }
        if (!entityCollection.IsLoaded)
        {
            entityCollection.Load();
        }

        int count = 0;
        var enumerator = entityCollection.GetEnumerator();
        while (enumerator.MoveNext())
            count++;

        HyperLink1.Text += " (" + count + ")";
    }

Answer 2

I have found a potential solution here 'FieldTemplates: Children.ascx: Displaying Count' : http://forums.asp.net/t/1466373.aspx/1

Answer 3

well, HyperLink1.Text ="SomeString" should make your hyperlink's text be "SomeString"

HyperLink1.Text = "View Children -"+numEntries+" entries";

should make the hyperlink say what you want it to say, so long as numEntries is the right number at the time, at least it works that way on my machine ..

What is the current result of your attempt?

Answer 4

I have a very simple generic solution using dynamic:

Override the OnDataBiding method in the Childrex.aspx.cs and use the following code to get the number of child entities.

// get the field using dynamic
dynamic dynamicField = FieldValue;

// get the count property (this is a valid property for an EnitySet)
int count = dynamicField.Count;