LibxmlNode -- the class of all XML nodes created by libxml2

Description

Each XML node created by libxml2 has: if it is an element (as determined by xmlIsElement), an optional element name, which is a string and is obtained with xmlGetName; if it is text (as determined by xmlIsText), an optional content string, obtained with xmlGetContent; a linked list of attributes of type LibxmlAttribute; a linked list of children (which are XML nodes), obtained with xmlFirstChild; and a pointer its next sibling, obtained with xmlGetNext.

XML nodes are mutable.

Internally, a pointer to the XML document containing the node accompanies the node.

Let’s use xmlParse to make an XML node.

i1 : n = xmlParse ///<foo> aabc <bar id="foo" name="too"> asdf </bar><coo/><coo>hi</coo><coo a="b">hi</coo></foo>///

o1 = <foo> aabc <bar id="foo" name="too"> asdf </bar><coo/><coo>hi</coo><coo a="b">hi</coo></foo>

o1 : LibxmlNode (xmlTypeDescription)

i2 : xmlIsElement n, xmlIsText n

o2 = (true, false)

o2 : Sequence

Since it is an element, we may use xmlGetName to get its name.

i3 : xmlGetName n

o3 = foo

We use xmlFirstChild to get the first node in the linked list of children, which happens to be text:

i4 : c = xmlFirstChild n

o4 = " aabc "

o4 : LibxmlNode (xmlTypeDescription)

i5 : xmlIsElement c, xmlIsText c

o5 = (false, true)

o5 : Sequence

We may follow the linked list of children of n.

i6 : c

o6 = " aabc "

o6 : LibxmlNode (xmlTypeDescription)

i7 : bar = xmlGetNext oo

o7 = <bar id="foo" name="too"> asdf </bar>

o7 : LibxmlNode (xmlTypeDescription)

i8 : xmlGetNext oo

o8 = <coo/>

o8 : LibxmlNode (xmlTypeDescription)

i9 : xmlGetNext oo

o9 = <coo>hi</coo>

o9 : LibxmlNode (xmlTypeDescription)

i10 : xmlGetNext oo

o10 = <coo a="b">hi</coo>

o10 : LibxmlNode (xmlTypeDescription)

i11 : xmlGetNext oo

Let’s examine the attributes of bar.

i12 : xmlFirstAttribute bar

o12 = id = "foo"

o12 : LibxmlAttribute

i13 : a = xmlGetNext oo

o13 = name = "too"

o13 : LibxmlAttribute

i14 : xmlGetNext oo

We may disassemble an attribute as follows.

i15 : xmlGetName a

o15 = name

i16 : b = xmlFirstChild a

o16 = "too"

o16 : LibxmlNode (xmlTypeDescription)

i17 : xmlGetNext oo

i18 : xmlIsText b

o18 = true

i19 : toString b

o19 = too

There are other functions that retrieve the entire list of attributes or children.

i20 : getChildren n

o20 = {" aabc "                             }
      {<bar id="foo" name="too"> asdf </bar>}
      {<coo/>                               }
      {<coo>hi</coo>                        }
      {<coo a="b">hi</coo>                  }

o20 : VerticalList

i21 : class \ oo

o21 = {LibxmlNode}
      {LibxmlNode}
      {LibxmlNode}
      {LibxmlNode}
      {LibxmlNode}

o21 : VerticalList

i22 : getAttributes bar

o22 = {id = "foo"  }
      {name = "too"}

o22 : VerticalList

i23 : class \ oo

o23 = {LibxmlAttribute}
      {LibxmlAttribute}

o23 : VerticalList

Functions and methods returning an object of class LibxmlNode :

toLibxmlNode, see toLibxmlNode(XMLnode) -- convert a hashtable of type XMLnode to an object of type LibxmlNode
xmlAddElement(LibxmlNode,String) -- add an element to an XML node
xmlAddText(LibxmlNode,String) -- add text to an XML node
xmlFirstChild(LibxmlAttribute), see xmlFirstChild -- get the first child of an XML node or attribute
xmlFirstChild(LibxmlNode), see xmlFirstChild -- get the first child of an XML node or attribute
xmlGetNext(LibxmlNode), see xmlGetNext -- get the next XML node or attribute
xmlNewRoot(String) -- create the root node of an XML document
xmlParse(String) -- parse a string containing XML

Methods that use an object of class LibxmlNode :

getAttributes(LibxmlNode) -- get the list of attributes of an XML node
getChildren(LibxmlNode), see getChildren -- get the list of children of an XML node
toXMLnode(LibxmlNode) -- convert an object of type LibxmlNode to a hashtable of type XMLnode
xmlAddAttribute(LibxmlNode,String,String) -- add an attribute to an XML node
xmlFirstAttribute(LibxmlNode) -- get the first attribute of an XML node
xmlGetContent(LibxmlNode) -- get the string content of an XML text node
xmlGetName(LibxmlNode), see xmlGetName -- get the name of an XML node or attribute
xmlIsElement(LibxmlNode) -- whether an XML node is an element
xmlIsText(LibxmlNode) -- whether an XML node is text
xmlType(LibxmlNode) -- the type code for an XML node
xmlTypeDescription(LibxmlNode) -- the type description for an XML node

For the programmer

The object LibxmlNode is a type, with ancestor class Thing.