om.DomNode.replaceChild

Replaces a node by another in the child nodes of the current node.

Syntax

replaceChild(
   newChild om.DomNode,
   oldChild om.DomNode)

newChild is a reference to the new node.
oldChild is the node to be replaced.

Usage

The replaceChild() method puts the om.DomNode element passed as first parameter at the place of the node referenced by the second parameter, in the children list of the object node calling the method.

The new child node passed to the replaceChild() method must have been created from the same DOM document object, for example with the om.DomDocument.createElement() method.

The old node is not destroyed, if it is still referenced by a variable. The old node still exists in the DOM document, but it is an orphan node, that can be attached to another parent node in the document.

Example

MAIN
    DEFINE doc  om.DomDocument,
           r om.DomNode,
           p om.DomNode,
           o om.DomNode,
           n om.DomNode

    LET doc = om.DomDocument.create("Items")

    LET r = doc.createElement("Zoo")

    LET p = doc.createElement("DodoList")
    CALL r.appendChild(p)

    LET o = doc.createElement("Dodo")
    CALL o.setAttribute("name", "momo")
    CALL o.setAttribute("gender", "male")
    CALL p.appendChild(o)

    CALL r.writeXml("file1.xml")

    LET n = doc.createElement("Dodo")
    CALL n.setAttribute("name", "kiki")
    CALL n.setAttribute("gender", "female")

    CALL p.replaceChild(n, o)

    -- o is orphan but still exists
    CALL o.writeXml("file2.xml")
    LET o = NULL -- unref/destroy the node

    CALL r.writeXml("file3.xml")
END MAIN

The above program will produce following files:

file1.xml

<?xml version='1.0' encoding='ASCII'?>
<Zoo>
  <DodoList>
    <Dodo name="momo" gender="male"/>
  </DodoList>
</Zoo>

file2.xml

<?xml version='1.0' encoding='ASCII'?>
<Dodo name="momo" gender="male"/>

file3.xml

<?xml version='1.0' encoding='ASCII'?>
<Zoo>
  <DodoList>
    <Dodo name="kiki" gender="female"/>
  </DodoList>
</Zoo>