Property Controls

Table of Contents

• Introduction
• Changing the Default Behavior for Built-In Properties
• Mapping Presentation of Properties through PropertyControlClassFactory

Introduction

Properties are rendered in different context but under the covers it is always a control implementing IPropertyControl in Web Forms, the defaul control is returned by the property implementation by overriding the method CreatePropertyControl from PropertyData . This is an introduction to different ways you can change rendering of properties.

Property Controls

The namespace EPiServer.Web.PropertyControls contains all the default controls for the built-in properties. The abstract base class PropertyDataControl does a lot of the underlying work, lessening the burden for developers creating custom controls. There is no need to inherit from any classes in this namespace. The only thing required is for custom controls to inherit from System.Web.UI.Control and implement the EPiServer.Core.IPropertyControl interface.

Some of the more important methods and properties on PropertyDataControl include:

Using PropertyControlBase<T> to change rendering

If you just want to change rendering of an existing property, perhaphs based on a tag you can use the PropertyControlBase<T> that allows you to use any user control. The same method can also be applied to a WebControl by implementing the interface IPropertyDataControl<T> yourself. Under the covers your control is being wrapped by a generic implementation of IPropertyControl. Example definition that renders an alternative to PageReference when tag "Testing" is being used.

[TemplateDescriptor(TagString="Testing")]
public partial class PropertyControlBaseSample : PropertyControlBase<PageReference>
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

Using Control Adapters for Properties

If you want to change rendering of a property depending on the web browser of the current request you can map a control adapter using a .browser-file . Since a control adapter has to inherit from an adapter base class EPiServer CMS has a base class called EPiServer.Web.PropertyControls.Adapters.PropertyDataControlAdapter to facilitate implementation of a custom control adapter for a property. PropertyDataControlAdapter implements many of the properties and methods that exist on PropertyDataControl and the default behavior is to redirect the method back to the current PropertyDataControl. This makes it a simple task to implement the specific methods that you want to change the behavior for. Following is a simple example of a control adapter that overrides the default behavior for EPiServer.Web.PropertyControls.PropertyLongStringControl :

public class PropertyLongStringControlAdapter : PropertyDataControlAdapter
    {
        public override void CreateDefaultControls()
        {
            Label l = new Label();
            l.Text = PropertyData.ToString();
            Control.Controls.Add(l);
        }
    }

Mapping Presentation of Properties through PropertyControlClassFactory

It's also possible to override what control should be used by mapping a PropertyClass through PropertyControlClassFactory. The following code shows how to map a property so that the second argument, that is required to inherit from Control and implement IPropertyControl, is used instead of the default control:

EPiServer.Core.PropertyControlClassFactory.Instance.RegisterClass(
                typeof(EPiServer.Core.PropertyNumber),
                typeof(MyNamespace.MyPropertyDataControl));