(Tcl) Removing / Deleting Child Nodes from XML

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>

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

set xml [new_CkXml]

# xyz is a CkXml

# The sample input XML is available at http://www.chilkatsoft.com/data/fruit.xml
set success [CkXml_LoadXmlFile $xml "fruit.xml"]
if {$success != 1} then {
    puts [CkXml_lastErrorText $xml]
    delete_CkXml $xml
    exit
}

# The RemoveChild method removes (discards) all direct
# children having the specified tag:
CkXml_RemoveChild $xml "fruit"

# Show the resulting XML:
puts "Result with all direct children having a tag equal to \"fruit\" removed:"
puts [CkXml_getXml $xml]

# 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:
set success [CkXml_LoadXmlFile $xml "fruit.xml"]

# The RemoveChildWithContent method removes the child
# having the exact content specified, regardless of the tag.  
# For example:
CkXml_RemoveChildWithContent $xml "pear"

# Show the resulting XML:
puts "Result with the node containing \"pear\" removed:"
puts [CkXml_getXml $xml]

# --------------------------------------------------------------------------
# Restore the original XML:
set success [CkXml_LoadXmlFile $xml "fruit.xml"]

# The RemoveChildByIndex method removes the Nth direct
# child.  Indexing begins at 0.  The "xyz" child is at index 4:
CkXml_RemoveChildByIndex $xml 4

# Show the resulting XML:
# Notice that the entire "xyz" subtree is removed.
puts "Result with the node at index 4 removed:"
puts [CkXml_getXml $xml]

# --------------------------------------------------------------------------
# Restore the original XML:
set success [CkXml_LoadXmlFile $xml "fruit.xml"]

# Navigate to the node with tag "xyz"
set xyz [CkXml_FindChild $xml "xyz"]

# Remove the "xyz" subtree making it it's own XML document
# with the "xyz" node at the root:
CkXml_RemoveFromTree $xyz

# Show both XML documents:
puts [CkXml_getXml $xyz]
puts [CkXml_getXml $xml]

# 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:
puts "xyz TreeId = [CkXml_get_TreeId $xyz]"
puts "xml TreeId = [CkXml_get_TreeId $xml]"

delete_CkXml $xyz


delete_CkXml $xml