format of an XML file when reading

[gadjet]

Hi,
Does anyone know if the layout of an xml file is important when using xmlreader to read the elements from and xml file.

I have a strange issue where if the source file is laid out like it would look in notepad++ using prety print and saved then it works just fine when reading in all the elements.

If the file is in one long line without any form of layout then saved, the program misses one specific element when looping through the elements and I've no idea why because there's nothing wrong with the element tag that gets missed.

One long line fails to read the <CNT-VERSION-INHALT> element

<?xml version="1.0" encoding="UTF-8" standalone="no"?><SW-CNT><IDENT><CNT-DATEI>LALaLALALa.xml</CNT-DATEI><CNT-VERSION-INHALT>1012</CNT-VERSION-INHALT><CNT-VERSION-DATUM>24-11-2016</CNT-VERSION-DATUM></IDENT>

formatted is OK

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<SW-CNT>
	<IDENT>
		<CNT-DATEI>LALaLALALa.xml</CNT-DATEI>
		<CNT-VERSION-INHALT>1012</CNT-VERSION-INHALT>
		<CNT-VERSION-DATUM>24-11-2016</CNT-VERSION-DATUM>
	</IDENT>

I've only shown the first part of the xml file due to sensitive information.

Any suggestions gratefully received
Thanks
Phil

[dday9]

Please show the code you are using to parse the XML.

[dbasnett]

Using your one line example I did this and it found that element,

        'to load from file
        ' Dim xe As XElement = XElement.Load("path")
        ' literal for testing
        Dim xe As XElement = <SW-CNT><IDENT><CNT-DATEI>LALaLALALa.xml</CNT-DATEI><CNT-VERSION-INHALT>1012</CNT-VERSION-INHALT><CNT-VERSION-DATUM>24-11-2016</CNT-VERSION-DATUM></IDENT></SW-CNT>
        Dim selXE As XElement
        selXE = xe...<CNT-VERSION-INHALT>.FirstOrDefault
        Stop 'examine selXE

So as dday said we need to see more.

[gadjet]

This is the If statement that captures the textfrom the element

If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "CNT-VERSION-INHALT" Then
    LblVerXml.Text = xmlR.ReadElementContentAsString
End If

[dbasnett]

This is the If statement that captures the textfrom the element

If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "CNT-VERSION-INHALT" Then
    LblVerXml.Text = xmlR.ReadElementContentAsString
End If

And? There is no context i.e. where is xmlR defined, is it part of a loop? If you are a beginner with XML you'll find XElement easier IMHO.

[dday9]

This is the If statement that captures the textfrom the element

Please show the code you are using to parse the XML.

[gadjet]

I will post more of the code next week as I don't have access to it at the moment as I'm not at work.

But the code I've got works without issue on an xml file formatted as per the pretty print view but fails to read one element out of many when it's formatted as a single line so the only difference is if the source file is saved in a formatted way or as a single line.

I was thinking it was a peculiarity of the xmlreader and the format of the source xml file as the code is the same when it works and when it skips the <CNT-VERSION-INHALT> element.

With the file formatted as a single line and stepping through the code the <CNT-VERSION-INHALT> start element is skipped completely and not seen as an element although the </CNT-VERSION-INHALT> end element and all other elements are seen OK
When the file formatted with lines and indentations is stepped through the <CNT-VERSION-INHALT> start element is seen correctly.

Thanks

[techgnome]

Then there's something going on... because it shouldn't matter. I've never seen a difference in how XML is processed based on its format. If it is seeing the ending tag, then it saw the start tag... so yeah, I think a closer look at the code is in order.

-tg

[gadjet]

OK here is the part of the code that reads in the xml file and searches through the tags to place parts of the data into labels on the form along with some other actions.

This code works perfectly for 99% of the time there's just some files that when opened the <CNT-VERSION-INHALT> start tag and data in missed, the only difference I can find is that saving the file formated with indents etc. works and saving as one long line doesn't work.

I cannot think of a reason for this happening, it doesn't make any sense whatsoever!

 Dim xmlR = XmlReader.Create(fn)
 Dim xmlFile As String
 Dim xmlfilenameArray() As String
 Try
     Do While xmlR.Read()
         If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "DATEN-NAME" Then
             xmlFile = xmlR.ReadElementContentAsString
             xmlfilenameArray = xmlFile.Split("_")
             'Load label texts from the xml filename data in dataset
             LblWinFileName.Text = fName
             Label7.Text = xmlFile ' xmlR.ReadElementContentAsString
             LblDA.Text = xmlfilenameArray(0)
             LblDiag.Text = xmlfilenameArray(1)
             'Check for a bootloader address
             If Microsoft.VisualBasic.Left(xmlfilenameArray(2), 2) = "71" Then
                 MsgBox("This appears to be a Bootloader Dataset" & vbCrLf & "This application cannot be used with Bootloader Datasets")
             Else
                 LblAddr.Text = xmlfilenameArray(2)
             End If

             LblProd.Text = xmlfilenameArray(3)
             LblVer.Text = xmlfilenameArray(4)
             LblName.Text = xmlfilenameArray(5)
             If xmlfilenameArray.Length > 6 Then
                 LblFreeText.Text = xmlfilenameArray(6)
             Else
                 LblFreeText.Text = ""
             End If
         End If
         'Extract the Start address from the specific tag
         If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "START-ADR" Then
             LblAddrXml.Text = xmlR.ReadElementContentAsString
         End If
         If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "CNT-VERSION-INHALT" Then
             LblVerXml.Text = xmlR.ReadElementContentAsString
         End If
         'Load first 16 Data bytes into variable then convert to ASCII
         Dim HexData As String

         If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "DATEN" Then
             HexData = xmlR.ReadElementContentAsString
             LblRawhex.Text = Microsoft.VisualBasic.Left(HexData, 8)
             LblDataNmeHex.Text = Microsoft.VisualBasic.Mid(HexData, 9, 24)
             TxtFullHex.Text = Microsoft.VisualBasic.Left(HexData, HexData.Length - 8)
             RichTextBox1.Text = Microsoft.VisualBasic.Left(HexData, HexData.Length - 8)
             LblXmlCrc.Text = Microsoft.VisualBasic.Right(HexData, 8)
             Dim testString As String = TxtFullHex.Text
             Dim byteArray As Byte() = Hex.ToByteArray(testString)
             Dim result As UInt32 = Crc32.ComputeChecksum(byteArray)
             Dim stringResult As String = result.ToString("X8") '6889CDCF
             LblCalcCRC.Text = stringResult

         End If

         'Extract full filename from the specific tag <CNT-DATEI>
         If xmlR.NodeType = XmlNodeType.Element AndAlso xmlR.Name = "CNT-DATEI" Then
             LblCNTDATEI.Text = xmlR.ReadElementContentAsString
         End If
     Loop
 Catch ex As Exception
     MsgBox("The File Specified Could not be opened" & vbCrLf & "Error message:" & vbCrLf & vbCrLf & ex.Message, MsgBoxStyle.OkOnly, "File Could Not Be Opened!")
 End Try

[dbasnett]

Try adding this setting and using it in your .Create method call.

https://learn.microsoft.com/en-us/do...norewhitespace

[gadjet]

Try adding this setting and using it in your .Create method call.

https://learn.microsoft.com/en-us/do...norewhitespace

Good call but made no difference :-(

[dbasnett]

Good call but made no difference :-(

So without seeing the actual file I'm out of suggestions. You should try the code in post #3 and see if it makes a difference.

[dday9]

Yeah, I would also suggest using an XDocument as opposed to an XmlReader.

Personally I find that the former is more intuitive than the latter but I don't know if there are any differences in the underlying parser.

[techgnome]

Personally I think there's something else wrong here ... I'd
1) post the code
2) post a copy of a file that DOES work
3) post a copy of a file that does NOT work


I think there's something else wrong with the borked xml and it isn't wholy format related. In all the years I've worked with XML, I've never had an issue except for when it was malformed ... which I'm suspecting is the case here...



-tg

[gadjet]

I'll give it a try with xDocument instead of xmlreader to see if that helps.
I can't really post the xml files but I can definitely confirm that the only difference is a "Save As" and the contents of the file are exactly the same unless Notepad++ is adding/removing stuff!

Thanks for taking the time to try to help, I'll update the post if I find something out.

Cheers

[dbasnett]

Assuming fn is the path to the XML file put this

        Dim xe As XElement = XElement.Load(fn) ' XElement.Load(fn,LoadOptions.PreserveWhitespace)
        xe.Save(fn)

immediately before

        Dim xmlR = XmlReader.Create(fn)
        Dim xmlFile As String
        Dim xmlfilenameArray() As String

to see if it makes a difference.

[gadjet]

Assuming fn is the path to the XML file put this

        Dim xe As XElement = XElement.Load(fn) ' XElement.Load(fn,LoadOptions.PreserveWhitespace)
        xe.Save(fn)

immediately before

        Dim xmlR = XmlReader.Create(fn)
        Dim xmlFile As String
        Dim xmlfilenameArray() As String

to see if it makes a difference.

Sneaky but it worked the re-written file has the formatting with indents etc.
Thanks

[dbasnett]

Sneaky but it worked the re-written file has the formatting with indents etc.
Thanks

But... after xe.Save add this. It will let us know if it is XmlReader.

        Dim selXE As XElement
        selXE = xe...<CNT-VERSION-INHALT>.FirstOrDefault
        Stop 'examine selXE