Interfaces: Rewrite ValidateZugferdDocument, add validation for invalid decimals

Interfaces/ZUGFeRDInterface.vb

@@ -39,6 +39,7 @@ Public Class ZUGFeRDInterface
         UnsupportedFormat
         FileTooBig
         UnknownError
+        ValidationFailed
     End Enum
 
     Public ReadOnly Property FileGroup As FileGroups
@@ -54,6 +55,7 @@ Public Class ZUGFeRDInterface
     Public Class ZugferdResult
         Public Property DataFileName As String
         Public Property XPathObject As XPathDocument
+        Public Property XElementObject As XElement
         Public Property SchemaObject As Object
         Public Property Specification As String
         Public Property ValidationErrors As New List(Of ZugferdValidationError)
@@ -246,13 +248,22 @@ Public Class ZUGFeRDInterface
         End If
 
         Try
+            Dim oXPathObject As XPathDocument = Nothing
             Using oStream As New MemoryStream(oAllowedResult.FileContents)
-                Return New ZugferdResult With {
-                    .DataFileName = oAllowedResult.FileName,
-                    .XPathObject = New XPathDocument(oStream)
-                }
+                oXPathObject = New XPathDocument(oStream)
             End Using
 
+            Dim oXElementObject As XElement = Nothing
+            Using oStream As New MemoryStream(oAllowedResult.FileContents)
+                oXElementObject = XElement.Load(oStream)
+            End Using
+
+            Return New ZugferdResult With {
+                .DataFileName = oAllowedResult.FileName,
+                .XElementObject = oXElementObject,
+                .XPathObject = oXPathObject
+            }
+
         Catch ex As ZUGFeRDExecption
             ' Don't log ZUGFeRD Exceptions here, they should be handled by the calling code.
             ' It also produces misleading error messages when checking if an attachment is a zugferd file.
@@ -276,48 +287,67 @@ Public Class ZUGFeRDInterface
         oNamespaceManager.AddNamespace("ram", "urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:12")
         oNamespaceManager.AddNamespace("rsm", "urn:ferd:CrossIndustryDocument:invoice:1p0")
 
+        Try
+            Dim oDecimalNodes = pResult.XElementObject.Descendants().
+            Where(Function(n) n.Name.ToString.EndsWith("Amount") Or n.Name.ToString.EndsWith("Percent"))
+
+            For Each oNode As XElement In oDecimalNodes
+                Dim oParsedValue As Decimal = 0.0
+                If Decimal.TryParse(oNode.Value, oParsedValue) = False Then
+                    pResult.ValidationErrors.Add(New ZugferdValidationError() With {
+                    .ElementName = oNode.Name.LocalName,
+                    .ElementValue = oNode.Value,
+                    .ErrorMessage = "Value could not be parsed as Decimal"
+                })
+                End If
+            Next
+
+        Catch ex As Exception
+            _logger.Error(ex)
+        End Try
+
         ' CurrencyCode Nodes
         Try
-            Dim oCurrencyCodeIterator As XPathNodeIterator = oNavigator.
-           Select("//ram:InvoiceCurrencyCode | //ram:TaxCurrencyCode | //ram:TaxCurrencyCode | //ram:SourceCurrencyCode", oNamespaceManager)
+            Dim oCurrencyCodeNodes = pResult.XElementObject.Descendants().
+                Where(Function(n) n.Name.ToString.EndsWith("CurrencyCode"))
 
-            While oCurrencyCodeIterator.MoveNext()
-                Dim oNode As XPathNavigator = oCurrencyCodeIterator.Current
+            For Each oNode As XElement In oCurrencyCodeNodes
                 Dim oValid = ValidateCurrencyCode(oNode.Value)
                 If oValid = False Then
                     pResult.ValidationErrors.Add(New ZugferdValidationError() With {
-                        .ElementName = oNode.Name,
+                        .ElementName = oNode.Name.LocalName,
                         .ElementValue = oNode.Value,
                         .ErrorMessage = "Invalid CurrencyCode. Only 3-Character codes are allowed."
                     })
                 End If
-            End While
+            Next
         Catch ex As Exception
             _logger.Error(ex)
         End Try
 
         ' currencyID
         Try
-            Dim oCurrencyIDIterator As XPathNodeIterator = oNavigator.Select("//*[@currencyID]")
+            Dim oCurrencyIDNodes = pResult.XElementObject.Descendants().
+                Where(Function(n) n.Attributes.Any(Function(a) a.Name.LocalName = "currencyID"))
 
-            While oCurrencyIDIterator.MoveNext()
-                Dim oNode As XPathNavigator = oCurrencyIDIterator.Current
-                Dim oCurrencyID As String = oNode.GetAttribute("currencyID", "")
+            For Each oNode As XElement In oCurrencyIDNodes
+                Dim oCurrencyID As String = oNode.Attribute("currencyID")?.Value
 
                 ' CurrencyID is optional per spec
                 If String.IsNullOrWhiteSpace(oCurrencyID) Then
-                    Continue While
+                    Continue For
                 End If
 
                 Dim oValid = ValidateCurrencyCode(oCurrencyID)
                 If oValid = False Then
                     pResult.ValidationErrors.Add(New ZugferdValidationError() With {
-                        .ElementName = oNode.Name,
+                        .ElementName = oNode.Name.LocalName,
                         .ElementValue = oCurrencyID,
                         .ErrorMessage = "Invalid currencyID. Only 3-Character codes or empty values are allowed."
                     })
                 End If
-            End While
+            Next
+
         Catch ex As Exception
             _logger.Error(ex)
         End Try