org.cyberneko.html.filters
public class ElementRemover extends DefaultFilter
The first option allows the application to specify which elements appearing in the event stream should be accepted and, therefore, passed on to the next stage in the pipeline. All elements not in the list of acceptable elements have their start and end tags stripped from the event stream unless those elements appear in the list of elements to be removed.
The second option allows the application to specify which elements should be completely removed from the event stream. When an element appears that is to be removed, the element's start and end tag as well as all of that element's content is removed from the event stream.
A common use of this filter would be to only allow rich-text and linking elements as well as the character content to pass through the filter — all other elements would be stripped. The following code shows how to configure this filter to perform this task:
ElementRemover remover = new ElementRemover(); remover.acceptElement("b", null); remover.acceptElement("i", null); remover.acceptElement("u", null); remover.acceptElement("a", new String[] { "href" });
However, this would still allow the text content of other
elements to pass through, which may not be desirable. In order
to further "clean" the input, the removeElement
option can be used. The following piece of code adds the ability
to completely remove any <SCRIPT> tags and content
from the stream.
remover.removeElement("script");
Note:
All text and accepted element children of a stripped element is
retained. To completely remove an element's content, use the
removeElement
method.
Note: Care should be taken when using this filter because the output may not be a well-balanced tree. Specifically, if the application removes the <HTML> element (with or without retaining its children), the resulting document event stream will no longer be well-formed.
Version: $Id: ElementRemover.java,v 1.5 2005/02/14 03:56:54 andyc Exp $
Field Summary | |
---|---|
protected Hashtable | fAcceptedElements Accepted elements. |
protected int | fElementDepth The element depth. |
protected int | fRemovalElementDepth The element depth at element removal. |
protected Hashtable | fRemovedElements Removed elements. |
protected static Object | NULL A "null" object. |
Method Summary | |
---|---|
void | acceptElement(String element, String[] attributes)
Specifies that the given element should be accepted and, optionally,
which attributes of that element should be kept.
|
void | characters(XMLString text, Augmentations augs) Characters. |
void | comment(XMLString text, Augmentations augs) Comment. |
protected boolean | elementAccepted(String element) Returns true if the specified element is accepted. |
protected boolean | elementRemoved(String element) Returns true if the specified element should be removed. |
void | emptyElement(QName element, XMLAttributes attributes, Augmentations augs) Empty element. |
void | endCDATA(Augmentations augs) End CDATA section. |
void | endElement(QName element, Augmentations augs) End element. |
void | endGeneralEntity(String name, Augmentations augs) End general entity. |
void | endPrefixMapping(String prefix, Augmentations augs) End prefix mapping. |
protected boolean | handleOpenTag(QName element, XMLAttributes attributes) Handles an open tag. |
void | ignorableWhitespace(XMLString text, Augmentations augs) Ignorable whitespace. |
void | processingInstruction(String target, XMLString data, Augmentations augs) Processing instruction. |
void | removeElement(String element)
Specifies that the given element should be completely removed. |
void | startCDATA(Augmentations augs) Start CDATA section. |
void | startDocument(XMLLocator locator, String encoding, NamespaceContext nscontext, Augmentations augs) Start document. |
void | startDocument(XMLLocator locator, String encoding, Augmentations augs) Start document. |
void | startElement(QName element, XMLAttributes attributes, Augmentations augs) Start element. |
void | startGeneralEntity(String name, XMLResourceIdentifier id, String encoding, Augmentations augs) Start general entity. |
void | startPrefixMapping(String prefix, String uri, Augmentations augs) Start prefix mapping. |
void | textDecl(String version, String encoding, Augmentations augs) Text declaration. |
Parameters: element The element to accept. attributes The list of attributes to be kept or null if no attributes should be kept for this element. see #removeElement
Parameters: element The element to completely remove.