Default backing types

If the BackingType attribute has not been set for a property, the backing type will be automatically assigned to a PropertyDefinitionType where the corresponding EPiServer.Core.PropertyData.PropertyValueType matches the property type. That means that if there is a PropertyData implementation (can be a custom property) with matching PropertyValueType that definition will be used. Otherwise the backing type is assigned according to this table.

See built-in property types for details on using the correct type.

Sample code

Sample code using many of the attributes described in this article.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using EPiServer.Core;
using EPiServer.DataAnnotations;
using System.ComponentModel.DataAnnotations;
using EPiServer.Security;
using EPiServer;
using EPiServer.Web;
using EPiServer.Shell.ObjectEditing.EditorDescriptors;
using EPiServer.Shell.ObjectEditing;
using EPiServer.DataAbstraction;

namespace CodeSamples
{
    [ContentType(
        DisplayName="My Page Type",
        Description="Description for this page type",
        Order=1024,
        GUID="9CBBF910-CB5A-4C72-83AA-EDCF02E8A2BD",
        GroupName="My Group",
        AvailableInEditMode=true)]
    [AvailableContentTypes(Include = new Type[] { typeof(MyPageType2), typeof(MyPageType3) })]
    [Access(Users = "niis", Roles = "CmsEditors")]
    public class TypedPageWithAttributeSample : PageData
    {
        [Required]
        [Searchable]
        [CultureSpecific]
        [Editable(true)]
        [Display(
            Name = "My Heading",
            Description = "Heading for my page type.",
            GroupName = "My Tab",
            Order = 64)]
        public virtual string Heading { get; set; }

        //An integer between 0 and 130.
        [Range(0, 130)]
        public virtual int Age { get; set; }

        //Validating against a given regular expression.
        [RegularExpression("[SomeRegularExpression]")]
        public virtual string CustomValidation { get; set; }

        //A string with a maximum length of 20 characters.
        [StringLength(20)]
        public virtual string Header { get; set; }

        //Any URL
        public virtual Url RedirectPage { get; set; }

        //Reference to an image in the EPiServer media system.
        [UIHint(UIHint.Image)]
        public virtual ContentReference Logotype { get; set; }

        //URL to image is also supported but mostly for upgrade support or when there is a need to add custom query parameters to the URL.
        [UIHint(UIHint.Image)]
        public virtual Url LogotypeAsUrl { get; set; }

        //Creates a selection of predefined values.
        [SelectOne(SelectionFactoryType=typeof(CustomLanguageSelectionFactory))]
        public virtual string LanguageSelection { get; set; }

         //Creates a selection of predefined values with the option to select several items.
        [SelectMany(SelectionFactoryType=typeof(CustomLanguageSelectionFactory))]
        public virtual string MultipleLanguageSelection { get; set; }
    }

    public class CustomLanguageSelectionFactory : ISelectionFactory
    {
        public IEnumerable<ISelectItem> GetSelections(ExtendedMetadata metadata)
        {
            var languages = new List<SelectItem>();

            languages.Add(new SelectItem() { Text = "English", Value = "en"});
            languages.Add(new SelectItem() { Text = "Swedish", Value = "sv" });
            languages.Add(new SelectItem() { Text = "Norwegian", Value = "no" });

            return languages;
        }
    }

    [AvailableContentTypes(IncludeOn = new Type[] { typeof(TypedPageWithAttributeSample) })]
    [ContentType]
    public class MyPageType1 : PageData { }

    [AvailableContentTypes(Exclude = new Type[] { typeof(TypedPageWithAttributeSample) })]
    [ContentType]
    public class MyPageType2 : PageData { }

    [AvailableContentTypes(ExcludeOn = new Type[] { typeof(MyPageType1) })]
    [ContentType]
    public class MyPageType3 : PageData { }

    [AvailableContentTypes(Availability = Availability.None)]
    [ContentType]
    public class MyPageType4 : PageData { }
}