我创建了一个带有ImageUrl属性和Description属性的ImageBlock。 ImageUrl是必需的。
[ContentType(
DisplayName = "Image",
Description = "Image with description and caption",
GUID = "387A029C-F193-403C-89C9-375A2A6BF028",
AvailableInEditMode = false)]
public class ImageBlock : BaseBlock
{
[Required]
[UIHint(UIHint.Image)]
[Display(
Name = "Image Url",
Description = "",
GroupName = SystemTabNames.Content,
Order = 10)]
public virtual Url ImageUrl { get; set; }
[Display(
Name = "Image Description",
Description = "A description of the image",
GroupName = SystemTabNames.Content,
Order = 20)]
public virtual string Description { get; set; }
}
我的ArticlePage使用此ImageBlock作为其Image属性,但不需要在文章中包含图像。但是,如果编辑器选择了图像,则应该需要该URL。
[Display(
Name = "Image",
Description = "",
GroupName = SystemTabNames.Content,
Order = 20)]
public virtual ImageBlock Image { get; set; }
但是当我创建一个ArticlePage的新实例时,系统会提示我输入需要EPiServer声明的ImageUrl。我错过了什么吗?
答案 0 :(得分:2)
我找到了一种构建自定义属性的方法,如果设置了除所需的块属性之外的任何其他值,则检查会给出错误。因此,在我的情况下,如果例如编辑器输入图像描述的值并尝试发布而不指定ImageUrl,则会显示错误消息。
代码如下所示:
public class RequiredBlockPropertyAttribute : ValidationAttribute
{
private string _failedOnProperty = string.Empty;
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
return ValidateBlock(value, validationContext)
? ValidationResult.Success
: new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
private bool ValidateBlock(object value, ValidationContext validationContext)
{
var type = validationContext.ObjectType.BaseType;
if (type == null)
return true;
var properties = type.GetProperties().Where(prop =>
prop.DeclaringType != null
&& prop.DeclaringType.IsSubclassOf(typeof(BlockData)));
foreach (var property in properties)
{
if (!property.Name.Equals(validationContext.DisplayName))
{
var val = property.GetValue(validationContext.ObjectInstance, null);
if (val != null && (value == null || IsDateTimeMinValue(value)))
{
_failedOnProperty = property.Name;
return false;
}
}
}
return true;
}
private static bool IsDateTimeMinValue(object value)
{
DateTime t;
DateTime.TryParse(value.ToString(), out t);
return t == DateTime.MinValue;
}
public override string FormatErrorMessage(string name)
{
return string.Format(ErrorMessageString, name, _failedOnProperty);
}
块中的用法:
[RequiredBlockProperty(
ErrorMessage = "{1} cannot be set without {0} defined")]
[UIHint(UIHint.Image)]
[Display(
Name = "Image Url",
Description = "",
GroupName = SystemTabNames.Content,
Order = 10)]
public virtual Url ImageUrl { get; set; }