Edit this page

Custom Edit Forms

When the EditMode property of a table view is "EditForms" or "PopUp", the table view's EditFormSettings property lets you configure the edit form. One of the EditFormSettings sub-properties is EditFormType, which lets you specify whether you want to use the built-in edit form or substitute your own custom edit form.

There are three possible settings for EditFormType:

  • AutoGenerated: When EditFormType is "AutoGenerated", the table view uses the built-in edit form.

  • WebUserControl: When EditFormType is "WebUserControl", you can supply a UserControl that the table view uses as an edit form.

  • Template: When EditFormType is "Template", you can supply a template that the table view uses to generate the edit form.

caution

Please note that all settings related to the edit form

are applied only if the EditFormType is "AutoGenerated". Otherwise a caption is not rendered automatically by RadGrid, however, you can add a custom caption in the edit form template or user control edit form.

WebUserControl

When EditFormType is "WebUserControl", you can supply a UserControl to act as a custom edit form.

Referring to the UserControl from the grid

If you need a reference to the UserControl from an event handler of your RadGrid control, (for example, when the "Update" button is pressed), you must take into account that the UserControl is a Container that is placed inside another Container (the EditFormCell). The following example shows how you can access the custom UserControl:

UserControl MyUserControl = editFormItem.FindControl(GridEditFormItem.EditFormUserControlID) as UserControl;
Dim MyUserControl As UserControl = CType(editFormItem.FindControl(GridEditFormItem.EditFormUserControlID), UserControl)

Accessing the edited grid item from the user control

When RadGrid loads the UserControl Edit Form, the UserControl has full access to the properties of the grid item in which it is loaded. Inside the UserControl, you can access the grid item using the Parent.NamingContainer property:

GridEditableItem editedItem = this.Parent.NamingContainer;
Dim editedItem As GridEditableItem = Me.Parent.NamingContainer

Once you have a reference to the GridEditableItem object, you can access any of its properties, such as cell text values, the DataItem object (available in DataBinding event handler), and so on.

Accessing the page from the user control

You can use the Page property of the user control to access the Web page that holds the grid instance:

MyPageClassName myPage = this.Page;
Dim myPage As MyPageClassName = Me.Page

Binding controls inside the UserControl

When implementing a UserControl to act as a custom edit form, there are three ways you can handle exchanging data between the RadGrid control and your UserControl implementation:

  • Using DataBinder expressions to bind directly to a data item from the RadGrid instance.

  • Declaring a DataItem property and binding controls in the UserControl from this property's value.

  • Setting control properties directly without using any binding expressions.

Binding directly to a data item

To access data from the object that the custom edit form is binding to, the binding expression used in controls inside the UserControl should be implemented in a slightly different way than usual. This is because the controls are not directly inside the binding container: they are inside the UserControl, which is in turn inside the binding container. The controls must bind to GridEditFormItem instead of UserControl. Therefore, the binding expression needs to calculate properties for the parent's binding container.

Here is an example declaration of a TextBox server control inside a UserControl that is bound to the Region property of the DataItem in RadGrid:

<asp:TextBox ID="TextBox1" runat="server" Text='<%# DataBinder.Eval( Container, "Parent.BindingContainer.DataItem.Region") %>' />

Using the DataItem Property

If you prefer to use simpler binding expressions when implementing a UserControl to act as a custom edit form, implement a property with the name DataItem. This property must be public and assignable from the type of object that constructs the data source for RadGrid.

For example, if you bind RadGrid to a DataSet, the DataItem property can be declared as:

private object _dataItem = null;
public object DataItem
{
    get
    {
        return this._dataItem;
    }
    set
    {
        this._dataItem = value;
    }
}
Private _dataItem As Object = Nothing
Public Property DataItem As Object
    Get
        Return Me._dataItem
    End Get
    Set(ByVal value As Object)
        Me._dataItem = value
    End Set
End Property

The DataItem property should be declared as of type object. After loading the UserControl, RadGrid tries to assign the value of the DataItem property.

Once your UserControl has a DataItem property, you can use binding expressions such as the following:

<asp:TextBox ID="TextBox1" runat="server" Text='<%# Eval( "Country" ) %>'></asp:TextBox>

Setting properties without using binding expressions

You can handle the ItemDataBound event of the grid to access the controls in your UserControl and set their properties when the control is bound. In the ItemDataBound handler,

  1. Check whether the type of item is GridEditFormItem and whether the item is in edit mode.

  2. Locate the user control inside the GridEditFormItem and make the modifications you wish.

Here is an example that sets the text for a TextBox that resides inside the user control:

private void RadGrid1_ItemDataBound(object sender, Telerik.Web.UI.GridItemEventArgs e)
{
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode)
    {
        UserControl MyUserControl = e.Item.FindControl(GridEditFormItem.EditFormUserControlID) as UserControl;
        GridDataItem parentItem = (e.Item as GridEditFormItem).ParentItem;
        TextBox box = (TextBox)MyUserControl.FindControl("TextBox1");
        box.Text = parentItem["Country"].Text;
    }
}
Private Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound
    If (TypeOf e.Item Is GridEditFormItem AndAlso e.Item.IsInEditMode) Then
        Dim MyUserControl As UserControl = CType(e.Item.FindControl(GridEditFormItem.EditFormUserControlID), UserControl)
        Dim parentItem As GridDataItem = CType(e.Item, GridDataItem).ParentItem
        Dim box As TextBox = CType(MyUserControl.FindControl("TextBox1"), TextBox)
        box.Text = parentItem("Country").Text
    End If
End Sub

Binding selected values for drop-down lists

To select the proper item in a drop-down list inside your UserControl, handle the DataBinding event of the user control. Inside the event handler, bind the drop-down list and set its SelectedIndex accordingly:

private void MyEditForm_DataBinding(object sender, System.EventArgs e)
{
    String[] tocs = new string[] { "Dr.", "Mr.", "Mrs.", "Ms." };
    ddlTOC.DataSource = tocs;
    ddlTOC.DataBind();
    ddlTOC.SelectedIndex = tocs.IndexOf(DataBinder.Eval(DataItem, "TitleOfCourtesy").ToString());
    ddlTOC.DataSource = null;
}
Private Sub MyEditForm_DataBinding(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.DataBinding
    Dim tocs As String() = New String() {"Dr.", "Mr.", "Mrs.", "Ms."}
    ddlTOC.DataSource = tocs
    ddlTOC.DataBind()
    ddlTOC.SelectedIndex = tocs.IndexOf(DataBinder.Eval(DataItem, "TitleOfCourtesy").ToString())
    ddlTOC.DataSource = Nothing
End Sub
note

An important detail is to assign empty data source for the drop-down list to prevent binding it again at a later stage (when the rest of the edited item content is bound). The same conventions stand for nested user controls inside WebUserControl custom edit form or other controls such as listboxes, radiobutton lists, checkbox lists, and so on.

For a live example that shows a custom edit form implemented using a UserControl, see User control edit form.

Template

When EditFormType is "Template", you can supply a template that the table view uses to generate the edit form. To generate the template at design time, choose Edit Templates from the RadGrid Smart Tag. If the EditFormType for the table view has been set to "Template", the EditFormTemplate appears in the drop-down list of available templates. When you select that item, you can use the Template design surface to generate your template:

Binding controls inside the template

When using a template to implement a custom edit form, you can bind the items using DataBinder expressions:

<EditFormSettings editformtype="Template">
  <EditColumn uniquename="EditCommandColumn1"/>
  <FormTemplate>You can use traditional data binding<br/>Which require you to handle the updates yourself<br/>
    <asp:TextBox ID="TextBox1" runat="server" Text='<%# DataBinder.Eval( Container, "DataItem.Country" ) %>'/>
    <br/>When using automatic updates, you can use the Bind method<br/> 
    <asp:TextBoxID="TextBox2" runat="server" Text='<%# Bind("Country") %>' />  
  </FormTemplate>
  <PopUpSettings ScrollBars="None" />
<EditFormSettings>          

For a live example that shows a custom edit form implemented using a template, see Form template edit form.

note

When using Automatic DataSource operations, use the Bind() syntax to bind template controls. This allows the grid to extract updated values and pass them to the data source with no additional code on your part.

Setting properties without using binding expressions

Just like with the UserControl, when using a template form for a custom edit form, you can handle the ItemDataBound event of the grid to access the controls in edit form and set their properties when the control is bound. In the ItemDataBound handler,

  1. Check whether the type of item is GridEditFormItem and whether the item is in edit mode.

  2. Locate the user control inside the GridEditFormItem and make the modifications you wish.

Here is an example that sets the text for a TextBox that resides inside the form template:

private void RadGrid1_ItemDataBound(object sender, Telerik.Web.UI.GridItemEventArgs e)
{
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode)
    {
        GridEditFormItem editFormItem = e.Item as GridEditFormItem;
        GridDataItem parentItem = editFormItem.ParentItem;
        TextBox box = editFormItem.FindControl("TextBox1") as TextBox;
        box.Text = parentItem["Country"].Text;
    }
}
Private Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound
    If (TypeOf e.Item Is GridEditFormItem AndAlso e.Item.IsInEditMode) Then
        Dim editFormItem As GridEditFormItem = CType(e.Item, GridEditFormItem)
        Dim parentItem As GridDataItem = editFormItem.ParentItem
        Dim box As TextBox = CType(editFormItem.FindControl("TextBox1"), TextBox)
        box.Text = parentItem("Country").Text
    End If
End Sub

Creating FormTemplate custom edit form programmatically

You can create and assign the edit form template at runtime in the code-behind. To do this, you must design a class that implements the IBindableTemplate interface and assign an instance of that class to the EditFormSettings.FormTemplate property of the table view. As an added touch, you can add an ExtractValues method to facilitate extracting values from the edit form.

The following example illustrates this approach:

protected void Page_Init(object sender, EventArgs e)
{
    RadGrid grid1 = new RadGrid();
    grid1.DataSourceID = "SqlDataSource1";
    grid1.MasterTableView.EditFormSettings.EditFormType = GridEditFormType.Template;
    grid1.MasterTableView.EditFormSettings.FormTemplate = new MyEditFormTemplate();
    grid1.MasterTableView.Columns.Add(new GridEditCommandColumn());
    grid1.MasterTableView.DataKeyNames = new string[] { "ProviderName" };
    grid1.UpdateCommand += new GridCommandEventHandler(grid1_UpdateCommand);
    placeholder1.Controls.Add(grid1);
}
private void grid1_UpdateCommand(object source, GridCommandEventArgs e)
{
    GridEditableItem ei = ((GridEditableItem)(e.Item));
    Hashtable t1 = new Hashtable();
    ei.ExtractValues(t1);
}
public class MyEditFormTemplate : IBindableTemplate
{
    public void InstantiateIn(Control container)
    {
        GridEditFormItem item = ((GridEditFormItem)(container.NamingContainer));
        Button btn1 = new Button();
        btn1.CommandName = "Update";
        TextBox tb1 = new TextBox();
        tb1.ID = "MyTextBox";
        tb1.Text = item.ParentItem.OwnerTableView.DataKeyValues[((GridDataItem)(item.ParentItem)).ItemIndex]["ProviderName"].ToString();
        container.Controls.Add(tb1);
        container.Controls.Add(btn1);
    }
    public System.Collections.Specialized.IOrderedDictionary ExtractValues(System.Web.UI.Control container)
    {
        OrderedDictionary od = new OrderedDictionary();
        od.Add("ProviderName", ((TextBox)(((GridEditFormItem)(container)).FindControl("MyTextBox"))).Text);
        return od;
    }
}
Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
    Dim grid1 As RadGrid = New RadGrid()
    grid1.DataSourceID = "SqlDataSource1"
    grid1.MasterTableView.EditFormSettings.EditFormType = GridEditFormType.Template
    grid1.MasterTableView.EditFormSettings.FormTemplate = New MyEditFormTemplate()
    grid1.MasterTableView.Columns.Add(New GridEditCommandColumn())
    grid1.MasterTableView.DataKeyNames = New String() {"ProviderName"}
    AddHandler grid1.UpdateCommand, AddressOf grid1_UpdateCommand
    placeholder1.Controls.Add(grid1)
End Sub
Private Sub grid1_UpdateCommand(ByVal source As Object, ByVal e As GridCommandEventArgs)
    Dim ei As GridEditableItem = (DirectCast((e.Item), GridEditableItem))
    Dim t1 As New Hashtable()
    ei.ExtractValues(t1)
End Sub
Public Class MyEditFormTemplate Implements IBindableTemplate
    Public Sub InstantiateIn(ByVal container As Control)
        Dim item As GridEditFormItem = (DirectCast((container.NamingContainer), GridEditFormItem))
        Dim btn1 As New Button()
        btn1.CommandName = "Update"
        Dim tb1 As New TextBox()
        tb1.ID = "MyTextBox"
        tb1.Text = item.ParentItem.OwnerTableView.DataKeyValues((DirectCast((item.ParentItem), GridDataItem)).ItemIndex)("ProviderName").ToString()
        container.Controls.Add(tb1)
        container.Controls.Add(btn1)
    End Sub
    Public Function ExtractValues(ByVal container As System.Web.UI.Control) As System.Collections.Specialized.IOrderedDictionary
        Dim od As New OrderedDictionary()
        od.Add("ProviderName", (DirectCast(((DirectCast((container), GridEditFormItem)).FindControl("MyTextBox")), TextBox)).Text)
        Return od
    End Function
End Class