B4X

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. B4X

'  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 ChilkatXml
xml1.Initialize
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 ChilkatXml
xml2.Initialize
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 ChilkatStringBuilder
sbPath.Initialize

Dim i As Int = 0
Dim count_i As Int = xml2.NumChildrenHavingTag("phrase")
Do 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
Loop

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

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