(VB.NET) Find and Update an XML Attribute Value

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Demonstrates how to find an element in XML with a specified attribute name and then update the attribute value.

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' Let's say you have 2 XML files with identical structures as shown directly below,
' and you wish to update the values in the 1st XML file with those in the 2nd XML file.

' <global>
'     <phrase id="2FADisabled" value="2factor authentication disabled"/>
'     <phrase id="2FAEnabled" value="2factor authentication enabled"/>
'     <phrase id="2FAResetFailed" value="Failed to disable two factor authentication"/>
' </global>

' <global>
'     <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
'     <phrase id="2FADisabled" value="2FA authentication disabled"/>
'     <phrase id="2FAEnabled" value="2FA authentication enabled"/>
' </global>


' First, initialize each of the Chilkat XML objects.
' These could be loaded from files, but we'll just create them manually for this example..

Dim xml1 As New Chilkat.Xml
xml1.Tag = "global"
xml1.UpdateAttrAt("phrase",True,"id","2FADisabled")
xml1.UpdateAttrAt("phrase",True,"value","2factor authentication disabled")
xml1.UpdateAttrAt("phrase[1]",True,"id","2FAEnabled")
xml1.UpdateAttrAt("phrase[1]",True,"value","2factor authentication enabled")
xml1.UpdateAttrAt("phrase[2]",True,"id","2FAResetFailed")
xml1.UpdateAttrAt("phrase[2]",True,"value","Failed to disable two factor authentication")

Dim xml2 As New Chilkat.Xml
xml2.Tag = "global"
xml2.UpdateAttrAt("phrase",True,"id","2FAResetFailed")
xml2.UpdateAttrAt("phrase",True,"value","Failed to reset two factor authentication")
xml2.UpdateAttrAt("phrase[1]",True,"id","2FADisabled")
xml2.UpdateAttrAt("phrase[1]",True,"value","2FA authentication disabled")
xml2.UpdateAttrAt("phrase[2]",True,"id","2FAEnabled")
xml2.UpdateAttrAt("phrase[2]",True,"value","2FA authentication enabled")

' Iterate over attribute values in xml2 and update the same in xml1.


Dim phrase_id As String
Dim phrase_value As String

Dim sbPath As New Chilkat.StringBuilder

Dim i As Integer = 0
Dim count_i As Integer = xml2.NumChildrenHavingTag("phrase")
While i < count_i
    xml2.I = i
    phrase_id = xml2.ChilkatPath("phrase[i]|(id)")
    phrase_value = xml2.ChilkatPath("phrase[i]|(value)")

    ' Notice how the UpdateAttrAt method's 1st argument is a Chilkat path -- which is an expression
    ' to find the location of the XML element to be updated.
    ' Here we create a path of the form "/A/tagName,attributeName,attributeValuePattern", which means
    ' find the direct descendent of xml2 having tag=tagName, with an attribute=attributeName where the attribute value
    ' matches the attributeValuePattern.  If attributeValuePattern does not contain a "*", then it must match directly.
    ' We'll build a Chilkat path such as "/A/phrase,id,2FADisabled"
    sbPath.SetString("/A/phrase,id,")
    sbPath.Append(phrase_id)

    ' This assumes the corresponding element exists in xml1.
    xml1.UpdateAttrAt(sbPath.GetAsString(),True,"value",phrase_value)

    i = i + 1
End While

' Now see how xml1 has been updated..
Debug.WriteLine(xml1.GetXml())