Lee Crowe

May 20, 2011

7276

(1 votes)

Multiple Selection Custom Property Base Control

On many occasions I have built custom properties which allow a user to select and sort options from an available list.

I am sure there are many alternative solutions to the one I am presenting here but I decided to build my own base control that would contain the common functionality .

The base class is named ‘PropertyMultipleSelectionBaseControl’ and can be downloaded from here.

An example of the rendered control is shown below:

The base class has the following properties and methods:

PropertyMultipleSelectionBaseControl Properties

SelectedValues – A List of string that represent the selected options

PropertyMultipleSelectionBaseControl Virtual Properties

The following properties can be overridden in the derived implementation:

AvailableItemsText – Get the available items text
SelectedItemsText - Gets the selected items text
AddButtonText – Gets the add button text
RemoveButtonText – Gets the remove button text
MoveUpText – The move up button tooltip text
MoveDownText – The move down button tooltip text
ListBoxWidth –The width in pixels of the list box
ListBoxRows – The number of rows in the list box
MinimumNumberOfSelectedValues – The minimum number of selected values
MaximumNumberOfSelectedValues – The maximum number of selected values
MinimumNumberOfSelectedValuesErrorMessageFormatString – The minimum number of selected values error message format string
MaximumNumberOfSelectedValuesErrorMessageFormatString – The maximum number of selected values error message format string

PropertyMultipleSelectionBaseControl Virtual Methods

The following methods can be overridden in the derived implementation:

GetBindableData – The method returns a Dictionary<string, string> object that the list boxes will be bound to.

Code Usage Examples

The following code demonstrates how the control can be used.

Simple Usage Example

This code example demonstrates how you would bind the list boxes to a collection of pages.

   1:  public class PropertySimpleMultipleSelectionPropertyControl : PropertyMultipleSelectionBaseControl

   2:  {

   3:      protected override string AvailableItemsText

   4:      {

   5:          get { return "Available Pages"; }

   6:      }

7:

   8:      protected override string SelectedItemsText

   9:      {

  10:          get { return "Selected Pages"; }

  11:      }

12:

  13:      protected override Dictionary<string, string> GetBindableData()

  14:      {

  15:          PageDataCollection pages = DataFactory.Instance.GetChildren(PageReference.StartPage);

  16:          return pages.ToDictionary(page => page.PageLink.ID.ToString(), page => page.PageName);

  17:      }

  18:  }

Advanced Usage Example

This code example demonstrates how you would create a control which comprises of the multiple selection functionality and other inputs. In this example the additional input is a Text Box which will capture the number of pages entered.

   1:  public class PropertyContentProviderSelectionControl : PropertyMultipleSelectionBaseControl

   2:  {

   3:      private TextBox _pageCountTextBox;

4:

   5:      protected override string AvailableItemsText

   6:      {

   7:          get { return "Available Content Providers"; }

   8:      }

9:

  10:      protected override string SelectedItemsText

  11:      {

  12:          get { return "Selected Content Providers"; }

  13:      }

14:

  15:      protected override Dictionary<string, string> GetBindableData()

  16:      {

  17:          var contentProviders = new PersonalizationEngine().GetVisitorGroupContentProviders();

  18:          return contentProviders.ToDictionary(contentProvider => contentProvider.UniqueId.ToString(),

  19:                                                  contentProvider => string.Format("{0}, {1}, {2}", contentProvider.GetVisitorGroupName(),

  20:                                                                                  contentProvider.ContentProviderTypeDisplayName,

  21:                                                                                  Page.Server.HtmlEncode(contentProvider.ContentProviderCriteria)).TrimEnd(' ', ','));

  22:      }

23:

  24:      public override void ApplyEditChanges()

  25:      {

  26:          base.ApplyEditChanges();

27:

  28:          int pageCount;

29:

  30:          if (!int.TryParse(_pageCountTextBox.Text, out pageCount) || pageCount < 0)

  31:          {

  32:              AddErrorValidator("You must enter a valid page count");

  33:              return;

  34:          }

35:

  36:          SelectedContentProviders selectedContentProviders = new SelectedContentProviders

  37:          {

  38:              PageCount = pageCount,

  39:              ContentProviderIds = SelectedValues.Select(current => new Guid(current)).ToList()

  40:          };

41:

  42:          SerializationHelper.SerializeObject(selectedContentProviders);

  43:          SetValue(selectedContentProviders);

  44:      }

45:

  46:      public override void CreateEditControls()

  47:      {

  48:          SelectedContentProviders selectedContentProviders = PropertyData.Value as SelectedContentProviders ??

  49:                                                              new SelectedContentProviders();

50:

  51:          if (selectedContentProviders.ContentProviderIds == null)

  52:              selectedContentProviders.ContentProviderIds = new List<Guid>();

53:

  54:          SelectedValues = selectedContentProviders.ContentProviderIds.Select(current => current.ToString()).ToList();

55:

  56:          // add page count

  57:          Label label = new Label { Text = "Page Count:&nbsp;" };

  58:          Controls.Add(label);

59:

  60:          _pageCountTextBox = new TextBox { ID = "PageCount", Text = selectedContentProviders.PageCount.ToString() };

  61:          Controls.Add(_pageCountTextBox);

62:

  63:          // add base multiple selection editing controls

  64:          base.CreateEditControls();

  65:      }

  66:  }