BeWoPlaner/BeWo/Validation/AttributeValidator.cs

using System.Globalization;
using System.Reflection;
using System.Windows.Controls;
using System.Windows.Data;

using BS.Shared.Extensions;

namespace BeWo.Validation
{
    public class AttributeValidator : ValidationRule
    {
        public BindingExpression ExpressionToValidate { get; set; }

        public override ValidationResult Validate(object pValue, CultureInfo pCultureInfo)
        {
            bool lValid = true;

            if (this.ExpressionToValidate != null)
            {
                PropertyInfo lPropInfo = null;
                object lCurrentObject = this.ExpressionToValidate.DataItem;

                // Claude: DataItem des Bindings und Eltern-Objekt des Ziel-Propertys festhalten,
                // damit kontextabhaengige Regeln den Klientenbezug auswerten koennen.
                // Bei "PrototypeVM.Notice" ist das DataItem die ServiceRecordListVM (kennt
                // WithoutClient), bei "Notice" in den EditViews die ServiceRecordVM selbst.
                object lDataItem = lCurrentObject;
                object lOwner = lCurrentObject;

                if (lCurrentObject != null)
                {
                    foreach (var iPropName in this.ExpressionToValidate.ParentBinding.Path.Path.Split("."))
                    {
                        lOwner = lCurrentObject; // Claude: vor dem GetValue merken
                        lPropInfo = lCurrentObject.GetType().GetProperty(iPropName);
                        lCurrentObject = lPropInfo.GetValue(lCurrentObject, null);
                    }
                }

                if (lPropInfo != null)
                {
                    var lAttributes = lPropInfo.GetCustomAttributes(typeof(ValidationAttribute), true);
                    if (lAttributes.Length > 0)
                    {
                        // Claude: DataItem hat Vorrang, weil dort der View-Zustand liegt
                        // (ServiceRecordListVM.WithoutClient); sonst greift das Eltern-Objekt.
                        var lContext = (lDataItem as ICustomerRelatedContext)
                                       ?? (lOwner as ICustomerRelatedContext);

                        lValid = ((ValidationAttribute) lAttributes[0]).Validate(pValue, lContext);
                    }
                }
            }
            
            if (!lValid)
            {
                
            }

// TODO: Nachricht, am besten als Property im ValidationAttribut
            return new ValidationResult(lValid, null);
        }
    }
}