Package freemarker.ext.dom

Class NodeModel

java.lang.Object

freemarker.ext.dom.NodeModel

All Implemented Interfaces:

freemarker.core._UnexpectedTypeErrorExplainerTemplateModel, WrapperTemplateModel, AdapterTemplateModel, TemplateHashModel, TemplateModel, TemplateNodeModel, TemplateNodeModelEx, TemplateSequenceModel

public abstract class NodeModel
extends Object
implements TemplateNodeModelEx, TemplateHashModel, TemplateSequenceModel, AdapterTemplateModel, WrapperTemplateModel, freemarker.core._UnexpectedTypeErrorExplainerTemplateModel

A base class for wrapping a single W3C DOM Node as a FreeMarker template model.

Note that DefaultObjectWrapper automatically wraps W3C DOM Node-s into this, so you may need do that with this class manually. However, before dropping the Node-s into the data-model, you certainly want to apply simplify(Node) on them.

This class is not guaranteed to be thread safe, so instances of this shouldn't be used as shared variable ( Configuration.setSharedVariable(String, Object)).

To represent a node sequence (such as a query result) of exactly 1 nodes, this class should be used instead of NodeListModel, as it adds extra capabilities by utilizing that we have exactly 1 node. If you need to wrap a node sequence of 0 or multiple nodes, you must use NodeListModel.

Field Summary

Fields inherited from interface freemarker.template.TemplateModel

NOTHING

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NodeModel(Node node)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)
TemplateModel	exec(List args)
Object[]	explainTypeError(Class[] expectedClasses)
TemplateModel	get(int i)	Retrieves the i-th template model in this sequence.
TemplateModel	get(String key)	Gets a TemplateModel from the hash.
Object	getAdaptedObject(Class hint)	Retrieves the underlying object, or some other object semantically equivalent to its value narrowed by the class hint.
TemplateSequenceModel	getChildNodes()
static DocumentBuilderFactory	getDocumentBuilderFactory()	Deprecated. The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!
static ErrorHandler	getErrorHandler()
TemplateNodeModelEx	getNextSibling()
Node	getNode()
String	getNodeNamespace()
String	getNodeType()
TemplateNodeModel	getParentNode()
TemplateNodeModelEx	getPreviousSibling()
Object	getWrappedObject()	Retrieves the original object wrapped by this model.
static Class	getXPathSupportClass()	Get the currently used freemarker.ext.dom.XPathSupport used as the XPath engine.
int	hashCode()
static void	mergeAdjacentText(Node parent)	Merges adjacent text nodes (where CDATA counts as text node too).
static NodeModel	parse(File f)	Deprecated. The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!
static NodeModel	parse(File f, boolean removeComments, boolean removePIs)	Deprecated. The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!
static NodeModel	parse(InputSource is)	Deprecated. The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!
static NodeModel	parse(InputSource is, boolean removeComments, boolean removePIs)	Deprecated. The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see earlier what do instead.
static void	removeComments(Node parent)	Recursively removes all comment nodes from the subtree.
static void	removePIs(Node parent)	Recursively removes all processing instruction nodes from the subtree.
static void	setDocumentBuilderFactory(DocumentBuilderFactory docBuilderFactory)	Deprecated. It's a bad practice to change static fields, as if multiple independent components do that in the same JVM, they unintentionally affect each other.
static void	setErrorHandler(ErrorHandler errorHandler)	Deprecated. It's a bad practice to change static fields, as if multiple independent components do that in the same JVM, they unintentionally affect each other.
static void	setXPathSupportClass(Class cl)	Set an alternative implementation of freemarker.ext.dom.XPathSupport to use as the XPath engine.
static void	simplify(Node parent)	Removes all comments and processing instruction, and unites adjacent text nodes (here CDATA counts as text as well).
int	size()	Always returns 1.
static void	useDefaultXPathSupport()	Tells the system to use (restore) the default (initial) XPath system used by this FreeMarker version on this system.
static void	useJaxenXPathSupport()	Convenience method.
static void	useSunInternalXPathSupport()
static void	useXalanXPathSupport()	Convenience method.
static NodeModel	wrap(Node node)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface freemarker.template.TemplateHashModel

isEmpty

Methods inherited from interface freemarker.template.TemplateNodeModel

getNodeName

Constructor Details

NodeModel

protected NodeModel(Node node)

Method Details

setDocumentBuilderFactory

@Deprecated
public static void setDocumentBuilderFactory(DocumentBuilderFactory docBuilderFactory)

Deprecated.

It's a bad practice to change static fields, as if multiple independent components do that in the same JVM, they unintentionally affect each other. Therefore, it's recommended to leave this static value at its default.

Sets the DOM parser implementation to be used when building NodeModel objects from XML files or from InputStream with the static convenience methods of NodeModel. Otherwise, FreeMarker itself doesn't use this.

See Also:

getDocumentBuilderFactory()

getDocumentBuilderFactory

@Deprecated
public static DocumentBuilderFactory getDocumentBuilderFactory()

Deprecated.

The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!

Returns the DOM parser implementation that is used when building NodeModel objects from XML files or from InputStream with the static convenience methods of NodeModel. Otherwise, FreeMarker itself doesn't use this.

See Also:

setDocumentBuilderFactory(DocumentBuilderFactory)

setErrorHandler

@Deprecated
public static void setErrorHandler(ErrorHandler errorHandler)

Deprecated.

It's a bad practice to change static fields, as if multiple independent components do that in the same JVM, they unintentionally affect each other. Therefore, it's recommended to leave this static value at its default.

Sets the error handler to use when parsing the document with the static convenience methods of NodeModel.

See Also:

getErrorHandler()

getErrorHandler

public static ErrorHandler getErrorHandler()

Since:

2.3.20

See Also:

setErrorHandler(ErrorHandler)

parse

@Deprecated
public static NodeModel parse(InputSource is,
 boolean removeComments,
 boolean removePIs)
                       throws SAXException,
IOException,
ParserConfigurationException

Deprecated.

The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see earlier what do instead.

Convenience method to create a NodeModel from a SAX InputSource; please see the security warning further down. Adjacent text nodes will be merged (and CDATA sections are considered as text nodes) as with mergeAdjacentText(Node). Further simplifications are applied depending on the parameters. If all simplifications are turned on, then it applies simplify(Node) on the loaded DOM.

Note that parse(...) is only a convenience method, and FreeMarker itself doesn't use it (except when you call the other similar static convenience methods, as they may build on each other). In particular, if you want full control over the DocumentBuilderFactory used, create the Node with your own DocumentBuilderFactory, apply simplify(Node) (or such) on it, then call wrap(Node).

Security warning: If the XML to load is coming from a source that you can't fully trust, you shouldn't use this method, as the DocumentBuilderFactory it uses by default supports external entities, and so it doesn't prevent XML External Entity (XXE) attacks. Note that XXE attacks are not specific to FreeMarker, they affect all XML parsers in general. If that's a problem in your application, OWASP has a cheat sheet to set up a DocumentBuilderFactory that has limited functionality but is immune to XXE attacks. Because it's just a convenience method, you can just use your own DocumentBuilderFactory and do a few extra steps instead (see earlier). Appart from the OWASP recommended features, it's recommended to set DocumentBuilderFactory.setNamespaceAware(boolean) and DocumentBuilderFactory.setIgnoringElementContentWhitespace(boolean) set to true.

Parameters:

removeComments - Whether to remove all comment nodes (recursively); this is like calling removeComments(Node)

removePIs - Whether to remove all processing instruction nodes (recursively); this is like calling removePIs(Node)

Throws:

SAXException

IOException

ParserConfigurationException

parse

@Deprecated
public static NodeModel parse(InputSource is)
                       throws SAXException,
IOException,
ParserConfigurationException

Deprecated.

The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!

Same as parse(is, true, true); don't miss the security warnings documented there.

Throws:

SAXException

IOException

ParserConfigurationException

parse

@Deprecated
public static NodeModel parse(File f,
 boolean removeComments,
 boolean removePIs)
                       throws SAXException,
IOException,
ParserConfigurationException

Deprecated.

The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!

Same as parse(InputSource, boolean, boolean), but loads from a File; don't miss the security warnings documented there.

Throws:

SAXException

IOException

ParserConfigurationException

parse

@Deprecated
public static NodeModel parse(File f)
                       throws SAXException,
IOException,
ParserConfigurationException

Deprecated.

The returned DocumentBuilderFactory is by default NOT SAFE from XXE attacks; see parse(InputSource, boolean, boolean) for more details!

Same as parse(source, true, true), but loads from a File; don't miss the security warnings documented there.

Throws:

SAXException

IOException

ParserConfigurationException

getNode

public Node getNode()

Returns:

the underling W3C DOM Node object that this TemplateNodeModel is wrapping.

get

public TemplateModel get(String key)
                  throws TemplateModelException

Description copied from interface: TemplateHashModel

Gets a TemplateModel from the hash.

Specified by:

get in interface TemplateHashModel

Parameters:

key - The name by which the TemplateModel is identified in the template.

Returns:

The TemplateModel referred to by the key, or null if not found.

Throws:

TemplateModelException

getParentNode

public TemplateNodeModel getParentNode()

Specified by:

getParentNode in interface TemplateNodeModel

Returns:

the parent of this node or null, in which case this node is the root of the tree.

getPreviousSibling

public TemplateNodeModelEx getPreviousSibling()
                                       throws TemplateModelException

Specified by:

getPreviousSibling in interface TemplateNodeModelEx

Returns:

The immediate previous sibling of this node, or null if there's no such node.

Throws:

TemplateModelException

getNextSibling

public TemplateNodeModelEx getNextSibling()
                                   throws TemplateModelException

Specified by:

getNextSibling in interface TemplateNodeModelEx

Returns:

The immediate next sibling of this node, or null if there's no such node.

Throws:

TemplateModelException

getChildNodes

public TemplateSequenceModel getChildNodes()

Specified by:

getChildNodes in interface TemplateNodeModel

Returns:

a sequence containing this node's children. If the returned value is null or empty, this is essentially a leaf node.

getNodeType

public final String getNodeType()
                         throws TemplateModelException

Specified by:

getNodeType in interface TemplateNodeModel

Returns:

a String describing the type of node this is. In the W3C DOM, this should be "element", "text", "attribute", etc. A TemplateNodeModel implementation that models other kinds of trees could return whatever it appropriate for that application. It can be null, if you don't want to use node-types.

Throws:

TemplateModelException

exec

public TemplateModel exec(List args)
                   throws TemplateModelException

Throws:

TemplateModelException

size

public final int size()

Always returns 1.

Specified by:

size in interface TemplateSequenceModel

Returns:

the number of items in the list.

get

public final TemplateModel get(int i)

Description copied from interface: TemplateSequenceModel

Retrieves the i-th template model in this sequence.

Specified by:

get in interface TemplateSequenceModel

Returns:

the item at the specified index, or null if the index is out of bounds. Note that a null value is interpreted by FreeMarker as "variable does not exist", and accessing a missing variables is usually considered as an error in the FreeMarker Template Language, so the usage of a bad index will not remain hidden, unless the default value for that case was also specified in the template.

getNodeNamespace

public String getNodeNamespace()

Specified by:

getNodeNamespace in interface TemplateNodeModel

Returns:

the XML namespace URI with which this node is associated. If this TemplateNodeModel implementation is not XML-related, it will almost certainly be null. Even for XML nodes, this will often be null.

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

wrap

public static NodeModel wrap(Node node)

removeComments

public static void removeComments(Node parent)

Recursively removes all comment nodes from the subtree.

See Also:

simplify(org.w3c.dom.Node)

removePIs

public static void removePIs(Node parent)

Recursively removes all processing instruction nodes from the subtree.

See Also:

simplify(org.w3c.dom.Node)

mergeAdjacentText

public static void mergeAdjacentText(Node parent)

Merges adjacent text nodes (where CDATA counts as text node too). Operates recursively on the entire subtree. The merged node will have the type of the first node of the adjacent merged nodes.

Because XPath assumes that there are no adjacent text nodes in the tree, not doing this can have undesirable side effects. Xalan queries like text() will only return the first of a list of matching adjacent text nodes instead of all of them, while Jaxen will return all of them as intuitively expected.

See Also:

simplify(org.w3c.dom.Node)

simplify

public static void simplify(Node parent)

Removes all comments and processing instruction, and unites adjacent text nodes (here CDATA counts as text as well). This is similar to applying removeComments(Node), removePIs(Node), and finally mergeAdjacentText(Node), but it does all that somewhat faster.

useDefaultXPathSupport

public static void useDefaultXPathSupport()

Tells the system to use (restore) the default (initial) XPath system used by this FreeMarker version on this system.

useJaxenXPathSupport

public static void useJaxenXPathSupport()
                                 throws Exception

Convenience method. Tells the system to use Jaxen for XPath queries.

Throws:

Exception - if the Jaxen classes are not present.

useXalanXPathSupport

public static void useXalanXPathSupport()
                                 throws Exception

Convenience method. Tells the system to use Xalan for XPath queries.

Throws:

Exception - if the Xalan XPath classes are not present.

useSunInternalXPathSupport

public static void useSunInternalXPathSupport()
                                       throws Exception

Throws:

Exception

setXPathSupportClass

public static void setXPathSupportClass(Class cl)

Set an alternative implementation of freemarker.ext.dom.XPathSupport to use as the XPath engine.

Parameters:

cl - the class, or null to disable XPath support.

getXPathSupportClass

public static Class getXPathSupportClass()

Get the currently used freemarker.ext.dom.XPathSupport used as the XPath engine. Returns null if XPath support is disabled.

getAdaptedObject

public Object getAdaptedObject(Class hint)

Description copied from interface: AdapterTemplateModel

Retrieves the underlying object, or some other object semantically equivalent to its value narrowed by the class hint.

Specified by:

getAdaptedObject in interface AdapterTemplateModel

Parameters:

hint - the desired class of the returned value. An implementation should make reasonable effort to retrieve an object of the requested class, but if that is impossible, it must at least return the underlying object as-is. As a minimal requirement, an implementation must always return the exact underlying object when hint.isInstance(underlyingObject) holds. When called with java.lang.Object.class, it should return a generic Java object (i.e. if the model is wrapping a scripting language object that is further wrapping a Java object, the deepest underlying Java object should be returned).

Returns:

the underlying object, or its value accommodated for the hint class.

getWrappedObject

public Object getWrappedObject()

Description copied from interface: WrapperTemplateModel

Retrieves the original object wrapped by this model.

Specified by:

getWrappedObject in interface WrapperTemplateModel

explainTypeError

public Object[] explainTypeError(Class[] expectedClasses)

Specified by:

explainTypeError in interface freemarker.core._UnexpectedTypeErrorExplainerTemplateModel