B4X

Removing / Deleting Child Nodes from XML

See more XML Examples

Demonstrates various methods for removing child nodes from an XML document.

The input XML, available at http://www.chilkatsoft.com/data/fruit.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

B4X

Dim success As Boolean = False

Dim xml As ChilkatXml
xml.Initialize
Dim xyz As ChilkatXml

'  The sample input XML is available at http://www.chilkatsoft.com/data/fruit.xml
success = xml.LoadXmlFile("fruit.xml")
If success <> True Then
    Log(xml.LastErrorText)
    Return
End If


'  The RemoveChild method removes (discards) all direct
'  children having the specified tag:
xml.RemoveChild("fruit")

'  Show the resulting XML:
Log("Result with all direct children having a tag equal to " & Chr(34) & "fruit" & Chr(34) & " removed:")
Log(xml.GetXml)

'  The XML with the "fruit" direct children removed is shown below:
'  Notice that the "fruit" node beneath "xyz" was not removed.
'  This correct because it was not a direct child of the calling node.

'  <root>
'      <veg color="orange">carrot</veg>
'      <meat animal="cow">beef</meat>
'      <xyz>
'          <fruit color="blue">blueberry</fruit>
'          <veg color="green">broccoli</veg>
'      </xyz>
'      <cheese color="yellow">cheddar</cheese>
'  </root>

'  --------------------------------------------------------------------------
'  Restore the original XML:
success = xml.LoadXmlFile("fruit.xml")

'  The RemoveChildWithContent method removes the child
'  having the exact content specified, regardless of the tag.  
'  For example:
xml.RemoveChildWithContent("pear")

'  Show the resulting XML:
Log("Result with the node containing " & Chr(34) & "pear" & Chr(34) & " removed:")
Log(xml.GetXml)

'  --------------------------------------------------------------------------
'  Restore the original XML:
success = xml.LoadXmlFile("fruit.xml")

'  The RemoveChildByIndex method removes the Nth direct
'  child.  Indexing begins at 0.  The "xyz" child is at index 4:
xml.RemoveChildByIndex(4)

'  Show the resulting XML:
'  Notice that the entire "xyz" subtree is removed.
Log("Result with the node at index 4 removed:")
Log(xml.GetXml)

'  --------------------------------------------------------------------------
'  Restore the original XML:
success = xml.LoadXmlFile("fruit.xml")

'  Navigate to the node with tag "xyz";
xyz = xml.FindChild("xyz")

'  Remove the "xyz" subtree making it it's own XML document
'  with the "xyz" node at the root:
xyz.RemoveFromTree

'  Show both XML documents:
Log(xyz.GetXml)
Log(xml.GetXml)

'  Also, the TreeId property is an integer value assigned
'  to nodes in an XML document.  All nodes belonging to
'  the same XML document will have the same TreeId.
'  Notice that the "xyz" node now has a different TreeId:
Log("xyz TreeId = " & xyz.TreeId)
Log("xml TreeId = " & xml.TreeId)