Required attribute

API Reference: RequiredAttribute Class

The RequiredAttribute can be applied to content model properties. The attribute specifies that this is a required property. The back office user interface will not accept empty values and display a validation message.


Decorate the property class with the RequiredAttribute. Optionally pass a validation message in the constructor which will be displayed when the user tries to save content while the value of this property is empty. If you do not set a custom validation message, a default culture-specific validation message is displayed.

Default Convention

If RequiredAttribute is not specified on a property, the property is not required if the type is nullable. This includes classes, strings, and Nullable<T> types. If the type is not nullable then the property is automatically required by convention. You can then still use the RequiredAttribute to change the validation message.


public class SampleContent: IContentModel
    // Nullable types need to be specified as required explicitly.
    [Required("This is a required property.")]
    public string RequiredText { get; set; }

    // Non-nullable types are always required by convention.
    public int Count { get; set; }