custom column breaks in DetailTables

[matt]

hello,

since the RadGrid columns have no simple property for "IsRequired" (which would make data-entry required in edit mode), i had to write my own custom column classes. they work in MasterTableViews. cool.

but, they dont work when used in DetailTables. when i use this:

<Nola:RequiredGridBoundColumn UniqueName="Name" HeaderText="Name" DataField="Name" MaxLength="50" />

i get this:

You must override Clone() for a derived grid column.

why is this?

here is the source code:

namespace CustomTelerikExtensions
{
    /// <summary>
    /// An extended GridBoundColumn that requires users to enter data into the GridBoundColumn's TextBox.
    /// </summary>
    public class RequiredGridBoundColumn : GridBoundColumn
    {
        public override void InitializeCell(TableCell cell, int columnIndex, GridItem gridItem)
        {
            base.InitializeCell(cell, columnIndex, gridItem);

            // if in edit mode && the editor is not null
            if (gridItem.IsInEditMode && cell.Controls[0] != null)
            {
                //assign ID of the default editor, if it is empty or null
                if (!Strings.Exists(cell.Controls[0].ID))
                    cell.Controls[0].ID = String.Format("{0}_TextBox", this.DataField);

                //add new required-field-validator
                RequiredFieldValidator requiredValidator = new RequiredFieldValidator();

                requiredValidator.ID = gridItem.OwnerGridID + "_RequiredFieldValidator" + columnIndex;
                requiredValidator.ControlToValidate = cell.Controls[0].ID;
                requiredValidator.Text = "&nbsp;Required";
                requiredValidator.CssClass = "required";

                string message = String.Format("\"{0}\" cannot be empty.", this.HeaderText);
                requiredValidator.ErrorMessage = message;
                requiredValidator.ToolTip = message;

                //add validator to the cell
                cell.Controls.Add(requiredValidator);
            }
        }

        //'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

        public override GridColumn Clone()
        {
            return base.Clone();
        }
    }
}

thanks,
matt

[matt]

telerik - what is up w/ this??

thanks

[Rosen]

Hi matt,

Basically you should create new instance of the current column and copy the current column's settings' values to the new one. This is necessary for the correct creation of the detail tables.

Best wishes,
Rosen
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[matt]

rosen,

i dont understand what you mean. can you please be more specific when replying -- eg, provide code examples?


thanks,
matt

[Rosen]

Hi matt,

As I stated in my previously message, you should created new column of the current column's type, copy the current column's properties and return the newly created column, similar to the following:

        public override GridColumn Clone()
        {
            RequiredGridBoundColumn requiredGridBoundColumn = new RequiredGridBoundColumn();
            //you should override CopyBaseProperties if you have some column specific properties
            requiredGridBoundColumn.CopyBaseProperties(this);

            return requiredGridBoundColumn;
        }

 
All the best,
Rosen
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.