XML-file --> Read --> Display selection

[Rens.Duijsens]

Hello,

I have been programming in VB6 for al long time.
Last week I installed Vistual Studio 2008.
(I hoped that would be easier.... But it is not, or is it just me?)

I'm trying to develop a programm that does the following:

1. Read in an XML-file
2. Display this file in a window
3. Let the user make an X-Path selection (later on, this should be possible by clicking on the data in the display window)
4. Gray out the not selected data, en highlight the selected data

I have been fighting with textReader and with XPathDocument as well as XPathNavigator but I'm still not able to let them do what I need.

Can somebody please advise me on the best way to tackle this please?

[Phil Weber]

It actually is easier, once you learn the .NET Framework. Selecting XML nodes based on an XPath expression is easy. The hard part is highlighting the selected nodes. Please see the attached project.

[Rens.Duijsens]

WOW!

This is GREAT!
This is exactly what I need for a basis.
I'll build further from this.

You made my life a LOT easier.

Great big bombastic thanky. (Jar Jar Binx)

Thanks

Rens

[Hack]

Originally Posted by Phil Weber

It actually is easier, once you learn the .NET Framework. Selecting XML nodes based on an XPath expression is easy. The hard part is highlighting the selected nodes. Please see the attached project.

Very nice Phil! :thumbs up:

[Rens.Duijsens]

Originally Posted by Phil Weber

The hard part is highlighting the selected nodes. Please see the attached project.

And so it is. :-)

I've tried the following XML testfile:

<?xml version="1.0"?>
<ROOT NodeNo="1" pattern="test">
   <NODE NodeNo="2">
      <ELEMENT NodeNo="3">Element 1</ELEMENT>
      <ELEMENT NodeNo="4">Element 2</ELEMENT>
      <ELEMENT NodeNo="5">Element 3</ELEMENT>
   </NODE>
   <NODE NodeNo="6">
      <ELEMENT NodeNo="7">Element 1</ELEMENT>
      <ELEMENT NodeNo="8">Element 2</ELEMENT>
      <ELEMENT NodeNo="9">Element 3</ELEMENT>
   </NODE>
</ROOT>

Selection: //ELEMENT
and all works fine.

<?xml version="1.0"?>
<ROOT NodeNo="1" pattern="test">
   <NODE NodeNo="2">
     <ELEMENT NodeNo="3">Element 1</ELEMENT>
      <ELEMENT NodeNo="4">Element 2</ELEMENT>
      <ELEMENT NodeNo="5">Element 3</ELEMENT>
   </NODE>
   <NODE NodeNo="6">
     <ELEMENT NodeNo="7">Element 1</ELEMENT>
      <ELEMENT NodeNo="8">Element 2</ELEMENT>
      <ELEMENT NodeNo="9">Element 3</ELEMENT>
   </NODE>
</ROOT>

But now......
Select: //ELEMENT/text()
And we see:

<?xml version="1.0"?>
<ROOT NodeNo="1" pattern="test">
   <NODE NodeNo="2">
      <ELEMENT NodeNo="3">Element 1</ELEMENT>
      <ELEMENT NodeNo="4">Element 2</ELEMENT>
      <ELEMENT NodeNo="5">Element 3</ELEMENT>
   </NODE>
   <NODE NodeNo="6">
      <ELEMENT NodeNo="7">Element 1</ELEMENT>
      <ELEMENT NodeNo="8">Element 2</ELEMENT>
      <ELEMENT NodeNo="9">Element 3</ELEMENT>
   </NODE>
</ROOT>

The texts in NodeNo 7, 8, 9 are not highlighted.

The regular expression just finds the first instance.
And so would //ELEMENT fail if you would leave out the attributes. Than only the first set of ELEMENT's will be highlighted.
Same reason. :-)

I'll figure it out. :-)

(Did I mention, I' very happy with the example code?)

Rens

[Rens.Duijsens]

Originally Posted by Rens.Duijsens

I'll figure it out. :-)

Oke....

It might be a very simple way for a solution, but it works. :-)

The code for HighlightSelectedNodes() looks like this now.

Private Sub HighlightSelectedNodes(ByVal Nodes As XmlNodeList)

    ' Clear previous selection
    With RichTextBox1
        .SelectAll()
        .SelectionColor = Color.Gray
        .SelectionFont = New Font(.Font, FontStyle.Regular)
    End With

    If Nodes.Count > 0 Then
        For Each Node As XmlNode In Nodes
            Debug.WriteLine(Node.OuterXml)

            ' Q&D Solution (Rens)
            Dim num_Index As Integer = InStr(1, RichTextBox1.Text, Node.OuterXml)
            While num_Index > 0
                With RichTextBox1
                    .SelectionStart = num_Index - 1
                    .SelectionLength = Len(Node.OuterXml)
                    .SelectionColor = Color.Black
                    .SelectionFont = New Font(.Font, FontStyle.Bold)
                End With

                num_Index = InStr(num_Index + 1, RichTextBox1.Text, Node.OuterXml)
            End While
        Next
    End If
End Sub

[Rens.Duijsens]

Originally Posted by Rens.Duijsens

It might be a very simple way for a solution, but it works. :-)

Yep.... It's TO simple a solution. :-)

Selections that have single lines a a result work fine, like //ELEMENT, but results that are bigger do not work like //NODE. :-(

Back to the drawing board.
:-)

[Hack]

Originally Posted by Rens.Duijsens

Selections that have single lines a a result work fine, like //ELEMENT, but results that are bigger do not work like //NODE. :-(

What happens on the bigger ones?

[Rens.Duijsens]

All stays gray.....

The selected text is not found.
It's missing the CrLf or so.
I'm inverstigating.

[Rens.Duijsens]

The difference is, the text in the RichTextBox is indented, and the nodes resturned bij xpath are not.

The box contains:
"<?xml version="1.0"?> <ROOT pattern="test"> <NODE> <ELEMENT>Element 1</ELEMENT> <ELEMENT>Element 2</ELEMENT> <ELEMENT>Element 3</ELEMENT> </NODE> <NODE> <ELEMENT>Element 1</ELEMENT> <ELEMENT>Element 2</ELEMENT> <ELEMENT>Element 3</ELEMENT> </NODE> </ROOT> "
Mark the TAB's and CrLf's.

The nodes returned by Node.OuterXml contains:
"<NODE><ELEMENT>Element 1</ELEMENT><ELEMENT>Element 2</ELEMENT><ELEMENT>Element 3</ELEMENT></NODE>"
No TAB's and/or CrLf's.

So the compare says: No match!

[Phil Weber]

Sorry, try this:

    Private Sub HighlightSelectedNodes(ByVal Nodes As XmlNodeList)

        ' Clear previous selection
        With RichTextBox1
            .SelectAll()
            .SelectionColor = Color.Gray
            .SelectionFont = New Font(.Font, FontStyle.Regular)
        End With

        If Nodes.Count > 0 Then
            For Each Node As XmlNode In Nodes
                Debug.WriteLine(Node.OuterXml)

                Dim Matches As MatchCollection
                Dim Elements() As String = Split(Node.OuterXml, "><")
                If UBound(Elements) > 0 Then
                    Dim OpenTag As String = Elements(0) & ">"
                    Dim CloseTag As String = "<" & Elements(UBound(Elements))
                    Matches = Regex.Matches(RichTextBox1.Text, OpenTag & "(.+?)" & CloseTag, RegexOptions.Singleline)
                Else
                    Matches = Regex.Matches(RichTextBox1.Text, Node.OuterXml, RegexOptions.Singleline)
                End If

                For Each M As Match In Matches
                    With RichTextBox1
                        .SelectionStart = M.Index
                        .SelectionLength = M.Length
                        .SelectionColor = Color.Black
                        .SelectionFont = New Font(.Font, FontStyle.Bold)
                    End With
                Next
            Next
        End If

    End Sub

I had not considered multiple matches; my regular expression was only highlighting the first instance of each match.

[Rens.Duijsens]

Yep!
This works great.

Originally Posted by Phil Weber

my regular expression was only highlighting the first instance of each match.

Oke, oke.......
I read the message between the lines.
I really should brush up on my knowledge on regular expressions.

Thank you very much.
I'll be working on my project using this as a basis.

FYI
I'm building a help-tool for the creation of X-Path statements for StreamServe events.

Friendly greetings
Rens

[Rens.Duijsens]

Originally Posted by Rens.Duijsens

I'll be working on my project using this as a basis.

I have a question.

I've added some buttons and textboxes.

lblPattern btnPattern
txtPattern

lblMatch btnMatch
txtMatch

lblValue btnValue
txtValue
and i have altered the code accordingly.

Now, however. No mather in wich textbox I enter an X-path statement, the moment I press <enter> the code btnMatch_Click is executed.

How come?
In VB6 there was a button property that could make a button react to enter or to escape. I can not find this here. Please advice.

Is it possible to let <enter> activate the button that is assigned to the textbox? (And is so, how do I do that please?)

Friendly grreetings
Rens

[Hack]

Look at the Forms Propertys

Look for an AcceptButton Property

Is btnMatch in this property?

[Phil Weber]

As Hack points out, if you want to dynamically change which button responds to the Enter key, you can either change the form's AcceptButton property as each textbox gets the focus, or you can handle the Enter key in each textbox's KeyDown event.