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.

  • 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

      public static DocumentBuilderFactory getDocumentBuilderFactory()
      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

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

      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

      public static NodeModel parse​(InputSource is) throws SAXException, IOException, ParserConfigurationException
      Same as parse(is, true, true); don't miss the security warnings documented there.
      Throws:
      SAXException
      IOException
      ParserConfigurationException

    • parse

      public static NodeModel parse​(File f, boolean removeComments, boolean removePIs) throws SAXException, IOException, ParserConfigurationException
      Same as parse(InputSource, boolean, boolean), but loads from a File; don't miss the security warnings documented there.
      Throws:
      SAXException
      IOException
      ParserConfigurationException

    • parse

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