public NodeListModel(Document document) 
{
                    
        nodes = document == null ? Collections.EMPTY_LIST : Collections12.singletonList(document);
        namespaces = new HashMap();
}

Creates a node list that holds a single Document node.

 public NodeListModel(Element element) 
{
        nodes = element == null ? Collections.EMPTY_LIST : Collections12.singletonList(element);
        namespaces = new HashMap();
}

Creates a node list that holds a single Element node.

 public NodeListModel(List nodes) 
{
        this(nodes, true);
}

Creates a node list that holds a list of nodes.

Parameters:

nodes - the list of nodes this template should hold. The created template will copy the passed nodes list, so changes to the passed list will not affect the model.

 public NodeListModel(List nodes,
    boolean copy) 
{
        this.nodes = copy && nodes != null ? new ArrayList(nodes) : (nodes == null ? Collections.EMPTY_LIST : nodes);
        namespaces = new HashMap();
}

Creates a node list that holds a list of nodes.

Parameters:

nodes - the list of nodes this template should hold.

copy - if true, the created template will copy the passed nodes list, so changes to the passed list will not affect the model. If false, the model will reference the passed list and will sense changes in it, although no operations on the list will be synchronized.

 public Object exec(List arguments) throws TemplateModelException 
{
        if (arguments == null || arguments.size() != 1)
            throw new TemplateModelException("Exactly one argument required for execute() on NodeTemplate");
        String xpathString = (String)arguments.get(0);
        JDOMXPathEx xpath = null;
        try
        {
            synchronized(XPATH_CACHE)
            {
                xpath = (JDOMXPathEx)XPATH_CACHE.get(xpathString);
                if (xpath == null)
                {
                    xpath = new JDOMXPathEx(xpathString);
                    XPATH_CACHE.put(xpathString, xpath);
                }
            }
            return createNodeListModel(xpath.selectNodes(nodes, namespaces), namespaces);
        }
        catch(Exception e)
        {
            throw new TemplateModelException("Could not evaulate XPath expression " + xpathString, e);
        }
}

Applies an XPath expression to the node list and returns the resulting node list. In order for this method to work, your application must have access Jaxen library classes. The implementation does cache the parsed format of XPath expressions in a weak hash map, keyed by the string representation of the XPath expression. As the string object passed as the argument is usually kept in the parsed FreeMarker template, this ensures that each XPath expression is parsed only once during the lifetime of the FreeMarker template that contains it.

 public TemplateModel get(String key) throws TemplateModelException 
{
        if (isEmpty())
            return EMPTY;
        if (key == null || key.length() == 0)
            throw new TemplateModelException("Invalid key [" + key + "]");
        NodeOperator op = null;
        NamedNodeOperator nop = null;
        String name = null;
        switch (key.charAt(0)) {
            case '@":
                {
                    if (key.length() != 2 || key.charAt(1) != '*") {
                        // Generic attribute key
                        nop = NAMED_ATTRIBUTE_OP;
                        name = key.substring(1);
                    } else
                        // It is @*
                        op = ALL_ATTRIBUTES_OP;
                    break;
                }
            case '*":
                {
                    if (key.length() == 1)
                        op = ALL_CHILDREN_OP;
                    else
                        // Explicitly disallow any other identifier starting with asterisk
                        throw new TemplateModelException("Invalid key [" + key + "]");
                    break;
                }
            case 'x":
            case '_":
                {
                    op = (NodeOperator)OPERATIONS.get(key);
                    if (op == null) {
                        // Some special operation?
                        Integer specop = (Integer)SPECIAL_OPERATIONS.get(key);
                        if (specop != null) {
                            switch (specop.intValue()) {
                                case SPECIAL_OPERATION_COPY:
                                {
                                    synchronized(namespaces)
                                    {
                                        return new NodeListModel(nodes, (Map)((HashMap)namespaces).clone());
                                    }
                                }
                                case SPECIAL_OPERATION_UNIQUE:
                                    return new NodeListModel(removeDuplicates(nodes), namespaces);
                                case SPECIAL_OPERATION_FILTER_NAME:
                                    return new NameFilter();
                                case SPECIAL_OPERATION_FILTER_TYPE:
                                    return new TypeFilter();
                                case SPECIAL_OPERATION_QUERY_TYPE:
                                    return getType();
                                case SPECIAL_OPERATION_REGISTER_NAMESPACE:
                                    return new RegisterNamespace();
                                case SPECIAL_OPERATION_PLAINTEXT:
                                    return getPlainText();
                            }
                        }
                    }
                    break;
                }
        }
        if (op == null && nop == null) {
            nop = NAMED_CHILDREN_OP;
            name = key;
        }
        List list = null;
        if (op != null)
            list = evaluateElementOperation(op, nodes);
        else {
            String localName = name;
            Namespace namespace = Namespace.NO_NAMESPACE;
            int colon = name.indexOf(':");
            if (colon != -1) {
                localName = name.substring(colon + 1);
                String nsPrefix = name.substring(0, colon);
                synchronized(namespaces)
                {
                    namespace = (Namespace)namespaces.get(nsPrefix);
                }
                if (namespace == null) {
                    if (nsPrefix.equals("xml"))
                        namespace = Namespace.XML_NAMESPACE;
                    else
                        throw new TemplateModelException("Unregistered namespace prefix '" + nsPrefix + "'");
                }
            }
            list = evaluateNamedElementOperation(nop, localName, namespace, nodes);
        }
        return createNodeListModel(list, namespaces);
}

Provides node list traversal as well as special functions: filtering by name, filtering by node type, shallow-copying, and duplicate removal. While not as powerful as the full XPath support built into the #exec(List) method, it does not require the external Jaxen library to be present at run time. Below are listed the recognized keys. In key descriptions, "applicable to this-and-that node type" means that if a key is applied to a node list that contains a node of non-applicable type a TemplateMethodModel will be thrown. However, you can use _ftype key to explicitly filter out undesired node types prior to applying the restricted-applicability key. Also "current nodes" means nodes contained in this set.
• * or _children: all direct element children of current nodes (non-recursive). Applicable to element and document nodes.
• @* or _attributes: all attributes of current nodes. Applicable to elements only.
• _content the complete content of current nodes (non-recursive). Applicable to elements and documents.
• _text: the text of current nodes, one string per node (non-recursive). Applicable to elements, attributes, comments, processing instructions (returns its data) and CDATA sections. The reserved XML characters ('<' and '&') are escaped.
• _plaintext: same as _text, but does not escape any characters, and instead of returning a NodeList returns a SimpleScalar.
• _name: the names of current nodes, one string per node (non-recursive). Applicable to elements and attributes (returns their local name), entities, processing instructions (returns its target), doctypes (returns its public ID)
• _qname: the qualified names of current nodes in [namespacePrefix:]localName form, one string per node (non-recursive). Applicable to elements and attributes
• _cname: the canonical names of current nodes (namespace URI + local name), one string per node (non-recursive). Applicable to elements and attributes
• _nsprefix: namespace prefixes of current nodes, one string per node (non-recursive). Applicable to elements and attributes
• _nsuri: namespace URIs of current nodes, one string per node (non-recursive). Applicable to elements and attributes
• _parent: parent elements of current nodes. Applicable to element, attribute, comment, entity, processing instruction.
• _ancestor: all ancestors up to root element (recursive) of current nodes. Applicable to same node types as _parent.
• _ancestorOrSelf: all ancestors of current nodes plus current nodes. Applicable to same node types as _parent.
• _descendant: all recursive descendant element children of current nodes. Applicable to document and element nodes.
• _descendantOrSelf: all recursive descendant element children of current nodes plus current nodes. Applicable to document and element nodes.
• _document: all documents the current nodes belong to. Applicable to all nodes except text.
• _doctype: doctypes of the current nodes. Applicable to document nodes only.
• _fname: is a filter-by-name template method model. When called, it will yield a node list that contains only those current nodes whose name matches one of names passed as argument. Attribute names should NOT be prefixed with the at sign (@). Applicable on all node types, however has no effect on unnamed nodes.
• _ftype: is a filter-by-type template method model. When called, it will yield a node list that contains only those current nodes whose type matches one of types passed as argument. You should pass a single string to this method containing the characters of all types to keep. Valid characters are: e (Element), a (Attribute), n (Entity), d (Document), t (DocType), c (Comment), p (ProcessingInstruction), x (text). If the string anywhere contains the exclamation mark (!), the filter's effect is inverted.
• _type: Returns a one-character String SimpleScalar containing the typecode of the first node in the node list. Valid characters are: e (Element), a (Attribute), n (Entity), d (Document), t (DocType), c (Comment), p (ProcessingInstruction), x (text). If the type of the node is unknown, returns '?'. If the node list is empty, returns an empty string scalar.
• _unique: a copy of the current nodes that keeps only the first occurrence of every node, eliminating duplicates. Duplicates can occur in the node list by applying uptree-traversals _parent, _ancestor, _ancestorOrSelf, and _document. I.e. foo._children._parent will return a node list that has duplicates of nodes in foo - each node will have the number of occurrences equal to the number of its children. In these cases, use foo._children._parent._unique to eliminate duplicates. Applicable to all node types.
• _copy: a copy of the current node list. It is a shallow copy that shares the underlying node list with this node list, however it has a separate namespace registry, so it can be used to guarantee that subsequent changes to the set of registered namespaces does not affect the node lists that were used to create this node list. Applicable to all node types.
• _registerNamespace(prefix, uri): register a XML namespace with the specified prefix and URI for the current node list and all node lists that are derived from the current node list. After registering, you can use the nodelist["prefix:localname"] or nodelist["@prefix:localname"] syntaxes to reach elements and attributes whose names are namespace-scoped. Note that the namespace prefix need not match the actual prefix used by the XML document itself since namespaces are compared solely by their URI. You can also register namespaces from Java code using the #registerNamespace(String, String) method.
• @attributeName: named attributes of current nodes. Applicable to elements, doctypes and processing instructions. On doctypes it supports attributes publicId, systemId and elementName. On processing instructions, it supports attributes target and data, as well as any other attribute name specified in data as name="value" pair. The attribute nodes for doctype and processing instruction are synthetic, and as such have no parent. Note, however that @* does NOT operate on doctypes or processing instructions.
• any other key: element children of current nodes with name matching the key. This allows for convenience child traversal in book.chapter.title style syntax. Note that nodeset.childname is technically equivalent to nodeset._children._fname("childname"), but is both shorter to write and evaluates faster. Applicable to document and element nodes.
The order of nodes in the resulting set is the order of evaluation of the key on each node in this set from left to right. Evaluation of the key on a single node always yields the results in "natural" order (that of the document preorder traversal), even for uptree traversals. As a consequence, if this node list's nodes are listed in natural order, applying any of the keys will produce a node list that is also naturally ordered. As a special case, all node lists that are directly or indirectly generated from a single Document or Element node through repeated invocations of this method will be naturally ordered.

 public TemplateModel get(int i) throws TemplateModelException 
{
        try {
            return new NodeListModel(nodes.get(i), namespaces);
        } catch (IndexOutOfBoundsException e) {
            throw new TemplateModelException("Index out of bounds: " + e.getMessage());
        }
}

Retrieves the i-th element of the node list.

 public String getAsString() throws TemplateModelException 
{
        if (isEmpty())
            return "";
        java.io.StringWriter sw = new java.io.StringWriter(nodes.size() * 128);
        try {
            for (Iterator i = nodes.iterator(); i.hasNext();) {
                Object node = i.next();
                if (node instanceof Element)
                    OUTPUT.output((Element)node, sw);
                else if (node instanceof Attribute)
                    OUTPUT.output((Attribute)node, sw);
                else if (node instanceof String)
                    sw.write(OUTPUT.escapeElementEntities(node.toString()));
                else if (node instanceof Text)
                    OUTPUT.output((Text)node, sw);
                else if (node instanceof Document)
                    OUTPUT.output((Document)node, sw);
                else if (node instanceof ProcessingInstruction)
                    OUTPUT.output((ProcessingInstruction)node, sw);
                else if (node instanceof Comment)
                    OUTPUT.output((Comment)node, sw);
                else if (node instanceof CDATA)
                    OUTPUT.output((CDATA)node, sw);
                else if (node instanceof DocType)
                    OUTPUT.output((DocType)node, sw);
                else if (node instanceof EntityRef)
                    OUTPUT.output((EntityRef)node, sw);
                else
                    throw new TemplateModelException(node.getClass().getName() + " is not a core JDOM class");
            }
        } catch (IOException e) {
            throw new TemplateModelException(e.getMessage());
        }
        return sw.toString();
}

This method returns the string resulting from concatenation of string representations of its nodes. Each node is rendered using its XML serialization format, while text (String) is rendered as itself. This greatly simplifies creating XML-transformation templates, as to output a node contained in variable x as XML fragment, you simply write ${x} in the template.

 public boolean isEmpty() 
{
        return nodes.isEmpty();
}

Returns true if this model contains no nodes.

 public TemplateModelIterator iterator() 
{
        return new TemplateModelIterator()
        {
            private final Iterator it = nodes.iterator();
            public TemplateModel next()
            {
                return it.hasNext() ? new NodeListModel(it.next(), namespaces) : null;
            }
            public boolean hasNext() 
            {
                return it.hasNext();
            }
        };
}

 public static  void main(String[] args) throws Exception 
{
        org.jdom.input.SAXBuilder builder = new org.jdom.input.SAXBuilder();
        Document document = builder.build(System.in);
        SimpleHash model = new SimpleHash();
        model.put("document", new NodeListModel(document));
        FileReader fr = new FileReader(args[0]);
        Template template = new Template(args[0], fr);
        Writer w = new java.io.OutputStreamWriter(System.out);
        template.process(model, w);
        w.flush();
        w.close();
}

Loads a template from a file passed as the first argument, loads an XML document from the standard input, passes it to the template as variable document and writes the result of template processing to standard output.

 public  void registerNamespace(String prefix,
    String uri) 
{
        synchronized(namespaces)
        {
            namespaces.put(prefix, Namespace.getNamespace(prefix, uri));
        }
}

Registers an XML namespace with this node list. Once registered, you can refer to the registered namespace using its prefix in the #get(String) method from this node list and all other node lists that are derived from this node list. Use the nodelist["prefix:localname"] or the nodelist["@prefix:localname"] syntax to reach elements and attributes whose names are namespace-scoped. Note that the namespace prefix need not match the actual prefix used by the XML document itself since namespaces are compared solely by their URI. You can also register namespaces during template evaluation using the nodelist._registerNamespace(prefix, uri) syntax in the template. This mechanism is completely independent from the namespace declarations in the XML document itself; its purpose is to give you an easy way to refer to namespace-scoped elements in #get(String) and in XPath expressions passed to #exec(List) . Note also that the namespace prefix registry is shared among all node lists that are created from a single node list - modifying the registry in one affects all others as well. If you want to obtain a namespace "detached" copy of the node list, use the _copy key on it (or call nodeList.get("_copy") directly from your Java code. The returned node list has all the namespaces that the original node list has, but they can be manipulated independently thereon.

 public int size() 
{
        return nodes.size();
}