ASP.NET MVC - HtmlEncode all strings by default

Question

For example, a user creates a new question on a forum.

I send ajax to the server, then I use HtmlEncode to exclude the HTML code before saving it in the database.

Is it possible that HtmlEncode would be used automatically when receiving a request?

Also, when using the attribute (for example [HtmlAllowed]) you can allow html code in request.

Thanks

Answer 1

Thanks to Yegor Androsov, for pointing me to right direction.

This ModelBinder automaticaly encode all string properties, except that has [SafeHtml] attribute

public class SafeStringModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        HttpRequestBase request = controllerContext.HttpContext.Request;
        string name = bindingContext.ModelName;
        string value = request.Unvalidated[name];

        Type holderType = bindingContext.ModelMetadata.ContainerType;
        if (holderType != null)
        {
            PropertyInfo propertyType = holderType.GetProperty(bindingContext.ModelMetadata.PropertyName);
            if (propertyType == null) return value;

            object[] attributes = propertyType.GetCustomAttributes(true);
            bool hasAttribute = attributes.Cast<Attribute>().Any(a => a.GetType() == typeof (SafeHtmlAttribute));

            if (!hasAttribute && !string.IsNullOrEmpty(value))
            {
                value = HttpUtility.HtmlEncode(value);
            }
        }

        return value;
    }
}

[AttributeUsage(AttributeTargets.Property)]
public class SafeHtmlAttribute : Attribute { }