XML: Search and Destroy

[Cyb3rH4Xter]

Here's a sample xml file that my program writes:

<?xml version="1.0" encoding="utf-8"?>
<Movies>
  <MovieName xmlns="National Lampoons Barely Legal.avi">
    <Directory>C:\Downloads\Movies\National Lampoons Barely Legal  By Digitaljace.avi</Directory>
  </MovieName>
  <MovieName xmlns="Robin.Hood.S03E12.HDTV.XviD-BiA.avi">
    <Directory>C:\Downloads\Movies\Robin.Hood.S03E12.HDTV.XviD-BiA.avi</Directory>
  </MovieName>
  <MovieName xmlns="American.Pie.Beta.House DVDRIP.avi">
    <Directory>C:\Downloads\Movies\American Pie 1,2,3,4,5,6 DVDRIP\American.Pie.Beta.House DVDRIP.avi</Directory>
  </MovieName>
</Movies>

When the user press a button called Remove, the program should find the movie the user has marked in a listview (the name of the movie is the item name column 1) and delete it from the xml file.

Say i wanna remove robin hood. I mark the item in the listview, clicks remove, it removes it from the listview (i already know how) and then removes this node : <MovieName xmlns="Robin.Hood.S03E12.HDTV.XviD-BiA.avi">
and everything in it.

I saw some code related to XPath, but i don't understand directly.

It would be nice with an example.

[ForumAccount]

Actually you can use LINQ/lambdas to do this:

Public Function RemoveMovie(ByVal movieName As String) As Xml.XmlNode
    Dim document As New Xml.XmlDocument()
    Dim removeNode As Xml.XmlNode = Nothing
    document.Load("C:\test\movies.txt") 'path to your xml
 
    removeNode = document.GetElementsByTagName("MovieName").OfType(Of Xml.XmlNode) _
                         .Where(Function(node) node.NamespaceURI _
                                    .Contains(movieName)).FirstOrDefault()
 
    If removeNode IsNot Nothing Then
        removeNode.ParentNode.RemoveChild(removeNode)
        document.Save("C:\test\movies.txt") 'save the xml with the removed node
    End If
 
    Return removeNode
End Function
 
Public Sub DoSomething()
    Me.RemoveMovie("Robin")
End Sub

[kleinma]

Way to hide the fact you are downloading copyrighted material illegally off the internet.

[Cyb3rH4Xter]

No off topic please -.-

[ForumAccount]

No off topic please -.-

Uh... speaking of which, did you try the code?

[kleinma]

No off topic please -.-

You are barking up the wrong tree buddy.

[Cyb3rH4Xter]

yeah, the code looks like this:

    Public Function RemoveMovie(ByVal movieName As String) As Xml.XmlNode

        For Each lvItem As ListViewItem In ListView2.SelectedItems

            lvItem.Remove()

            Dim document As New Xml.XmlDocument()

            Dim removeNode As Xml.XmlNode = Nothing

            document.Load(dataFile) 'path to your xml

            removeNode = document.GetElementsByTagName("MovieName").OfType(Of Xml.XmlNode)().Where(Function(node) node.NamespaceURI.Contains(movieName)).FirstOrDefault()

            If removeNode IsNot Nothing Then

                removeNode.ParentNode.RemoveChild(removeNode)

                document.Save(dataFile) 'save the xml with the removed node

            End If

            Return removeNode

        Next

    End Function

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click

        For Each lvItem As ListViewItem In ListView2.SelectedItems

            lvItem.Remove()

            RemoveMovie(lvItem.Text)

        Next

    End Sub

But it doesn't remove anything? And it gives no errors.

[ForumAccount]

1. Why are you looping through the ListView twice?
2. The document should be loaded outside of the loop so that you aren't loading the document on each iteration.
3. The "node.NamespaceURI" property will return this part of the node in double quotes:

xmlns="Robin.Hood.S03E12.HDTV.XviD-BiA.avi"

So ensure that the ListViewItem's text is actually contained in there. If your ListViewItem's text is "Robin Hood" it obviously won't be removed because it's "Robin.Hood".

[Cyb3rH4Xter]

Thx dude!

But there is One thing that don't work now. Removing many items. If i select like 3 items in the listview and click remove, only the first marked item get's removed from the xml file, but all gets removed from the listview. So there's something with the loop.

Here's the code now:

    Public Function RemoveMovie(ByVal movieName As String) As Xml.XmlNode

        Dim document As New Xml.XmlDocument()

        Dim removeNode As Xml.XmlNode = Nothing

        document.Load(dataFile) 'path to your xml

        removeNode = document.GetElementsByTagName("Moviename").OfType(Of Xml.XmlNode)().Where(Function(node) node.NamespaceURI.Contains(movieName)).FirstOrDefault()

        If removeNode IsNot Nothing Then

            removeNode.ParentNode.RemoveChild(removeNode)

            document.Save(dataFile) 'save the xml with the removed node

        End If

        Return removeNode

    End Function

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click

        For Each lvItem As ListViewItem In ListView2.SelectedItems

            lvItem.Remove()

            RemoveMovie(lvItem.Text)

        Next

    End Sub

[ForumAccount]

Try it like this:

Public Sub RemoveMovies(ByVal ParamArray movies As String())
        Dim document As New Xml.XmlDocument()
        Dim removeNode As Xml.XmlNode = Nothing
        document.Load(dataFile)
 
        For Each movie As String In movies
            removeNode = document.GetElementsByTagName("MovieName").OfType(Of Xml.XmlNode)().Where(Function(node) node.NamespaceURI.Contains(movie)).FirstOrDefault()
            If removeNode IsNot Nothing Then
                removeNode.ParentNode.RemoveChild(removeNode)
            End If
        Next
 
        document.Save(dataFile)
 
    End Sub
 
    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        Me.RemoveMovies(Me.ListView2.Items.OfType(Of ListViewItem)().Select(Function(item) item.Text).ToArray())
    End Sub