// HTMLParser Library $Name: v1_6_20060319 $ - A java-based parser for HTML
// http://sourceforge.org/projects/htmlparser
// Copyright (C) 2003 Derrick Oswald
//
// Revision Control Information
//
// $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/PrototypicalNodeFactory.java,v $
// $Author: derrickoswald $
// $Date: 2006/03/19 15:01:24 $
// $Revision: 1.19 $
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
package org.htmlparser;
import java.io.Serializable;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
import org.htmlparser.lexer.Page;
import org.htmlparser.nodes.TextNode;
import org.htmlparser.nodes.RemarkNode;
import org.htmlparser.nodes.TagNode;
import org.htmlparser.tags.AppletTag;
import org.htmlparser.tags.BaseHrefTag;
import org.htmlparser.tags.BodyTag;
import org.htmlparser.tags.Bullet;
import org.htmlparser.tags.BulletList;
import org.htmlparser.tags.DefinitionList;
import org.htmlparser.tags.DefinitionListBullet;
import org.htmlparser.tags.Div;
import org.htmlparser.tags.DoctypeTag;
import org.htmlparser.tags.FormTag;
import org.htmlparser.tags.FrameSetTag;
import org.htmlparser.tags.FrameTag;
import org.htmlparser.tags.HeadingTag;
import org.htmlparser.tags.HeadTag;
import org.htmlparser.tags.Html;
import org.htmlparser.tags.ImageTag;
import org.htmlparser.tags.InputTag;
import org.htmlparser.tags.JspTag;
import org.htmlparser.tags.LabelTag;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.tags.MetaTag;
import org.htmlparser.tags.ObjectTag;
import org.htmlparser.tags.OptionTag;
import org.htmlparser.tags.ParagraphTag;
import org.htmlparser.tags.ProcessingInstructionTag;
import org.htmlparser.tags.ScriptTag;
import org.htmlparser.tags.SelectTag;
import org.htmlparser.tags.Span;
import org.htmlparser.tags.StyleTag;
import org.htmlparser.tags.TableColumn;
import org.htmlparser.tags.TableHeader;
import org.htmlparser.tags.TableRow;
import org.htmlparser.tags.TableTag;
import org.htmlparser.tags.TextareaTag;
import org.htmlparser.tags.TitleTag;
/**
* A node factory based on the prototype pattern.
* This factory uses the prototype pattern to generate new nodes.
* These are cloned as needed to form new {@link Text}, {@link Remark} and
* {@link Tag} nodes.
* <p>Text and remark nodes are generated from prototypes accessed
* via the {@link #setTextPrototype(Text) textPrototype} and
* {@link #setRemarkPrototype(Remark) remarkPrototype} properties respectively.
* Tag nodes are generated as follows:
* <p>Prototype tags, in the form of undifferentiated tags, are held in a hash
* table. On a request for a tag, the attributes are examined for the name
* of the tag to be created. If a prototype of that name has been registered
* (exists in the hash table), it is cloned and the clone is given the
* characteristics ({@link Attribute Attributes}, start and end position)
* of the requested tag.</p>
* <p>In the case that no tag has been registered under that name,
* a generic tag is created from the prototype acessed via the
* {@link #setTagPrototype(Tag) tagPrototype} property.</p>
* <p>The hash table of registered tags can be automatically populated with
* all the known tags from the {@link org.htmlparser.tags} package when
* the factory is constructed, or it can start out empty and be populated
* explicitly.</p>
* <p>Here is an example of how to override all text issued from
* {@link org.htmlparser.nodes.TextNode#toPlainTextString()
* Text.toPlainTextString()},
* in this case decoding (converting character references),
* which illustrates the use of setting the text prototype:
* <pre>
* PrototypicalNodeFactory factory = new PrototypicalNodeFactory ();
* factory.setTextPrototype (
* // create a inner class that is a subclass of TextNode
* new TextNode () {
* public String toPlainTextString()
* {
* String original = super.toPlainTextString ();
* return (org.htmlparser.util.Translate.decode (original));
* }
* });
* Parser parser = new Parser ();
* parser.setNodeFactory (factory);
* </pre></p>
* <p>Here is an example of using a custom link tag, in this case just
* printing the URL, which illustrates registering a tag:
* <pre>
*
* class PrintingLinkTag extends LinkTag
* {
* public void doSemanticAction ()
* throws
* ParserException
* {
* System.out.println (getLink ());
* }
* }
* PrototypicalNodeFactory factory = new PrototypicalNodeFactory ();
* factory.registerTag (new PrintingLinkTag ());
* Parser parser = new Parser ();
* parser.setNodeFactory (factory);
* </pre></p>
*/
public class PrototypicalNodeFactory
implements
Serializable,
NodeFactory
{
/**
* The prototypical text node.
*/
protected Text mText;
/**
* The prototypical remark node.
*/
protected Remark mRemark;
/**
* The prototypical tag node.
*/
protected Tag mTag;
/**
* The list of tags to return.
* The list is keyed by tag name.
*/
protected Map mBlastocyst;
/**
* Create a new factory with all tags registered.
* Equivalent to
* {@link #PrototypicalNodeFactory() PrototypicalNodeFactory(false)}.
*/
public PrototypicalNodeFactory ()
{
this (false);
}
/**
* Create a new factory.
* @param empty If <code>true</code>, creates an empty factory,
* otherwise create a new factory with all tags registered.
*/
public PrototypicalNodeFactory (boolean empty)
{
clear ();
mText = new TextNode (null, 0, 0);
mRemark = new RemarkNode (null, 0, 0);
mTag = new TagNode (null, 0, 0, null);
if (!empty)
registerTags ();
}
/**
* Create a new factory with the given tag as the only registered tag.
* @param tag The single tag to register in the otherwise empty factory.
*/
public PrototypicalNodeFactory (Tag tag)
{
this (true);
registerTag (tag);
}
/**
* Create a new factory with the given tags registered.
* @param tags The tags to register in the otherwise empty factory.
*/
public PrototypicalNodeFactory (Tag[] tags)
{
this (true);
for (int i = 0; i < tags.length; i++)
registerTag (tags[i]);
}
/**
* Adds a tag to the registry.
* @param id The name under which to register the tag.
* <strong>For proper operation, the id should be uppercase so it
* will be matched by a Map lookup.</strong>
* @param tag The tag to be returned from a {@link #createTagNode} call.
* @return The tag previously registered with that id if any,
* or <code>null</code> if none.
*/
public Tag put (String id, Tag tag)
{
return ((Tag)mBlastocyst.put (id, tag));
}
/**
* Gets a tag from the registry.
* @param id The name of the tag to return.
* @return The tag registered under the <code>id</code> name,
* or <code>null</code> if none.
*/
public Tag get (String id)
{
return ((Tag)mBlastocyst.get (id));
}
/**
* Remove a tag from the registry.
* @param id The name of the tag to remove.
* @return The tag that was registered with that <code>id</code>,
* or <code>null</code> if none.
*/
public Tag remove (String id)
{
return ((Tag)mBlastocyst.remove (id));
}
/**
* Clean out the registry.
*/
public void clear ()
{
mBlastocyst = new Hashtable ();
}
/**
* Get the list of tag names.
* @return The names of the tags currently registered.
*/
public Set getTagNames ()
{
return (mBlastocyst.keySet ());
}
/**
* Register a tag.
* Registers the given tag under every {@link Tag#getIds() id} that the
* tag has (i.e. all names returned by {@link Tag#getIds() tag.getIds()}.
* <p><strong>For proper operation, the ids are converted to uppercase so
* they will be matched by a Map lookup.</strong>
* @param tag The tag to register.
*/
public void registerTag (Tag tag)
{
String[] ids;
ids = tag.getIds ();
for (int i = 0; i < ids.length; i++)
put (ids[i].toUpperCase (Locale.ENGLISH), tag);
}
/**
* Unregister a tag.
* Unregisters the given tag from every {@link Tag#getIds() id} the tag has.
* <p><strong>The ids are converted to uppercase to undo the operation
* of registerTag.</strong>
* @param tag The tag to unregister.
*/
public void unregisterTag (Tag tag)
{
String[] ids;
ids = tag.getIds ();
for (int i = 0; i < ids.length; i++)
remove (ids[i].toUpperCase (Locale.ENGLISH));
}
/**
* Register all known tags in the tag package.
* Registers tags from the {@link org.htmlparser.tags tag package} by
* calling {@link #registerTag(Tag) registerTag()}.
* @return 'this' nodefactory as a convenience.
*/
public PrototypicalNodeFactory registerTags ()
{
registerTag (new AppletTag ());
registerTag (new BaseHrefTag ());
registerTag (new Bullet ());
registerTag (new BulletList ());
registerTag (new DefinitionList ());
registerTag (new DefinitionListBullet ());
registerTag (new DoctypeTag ());
registerTag (new FormTag ());
registerTag (new FrameSetTag ());
registerTag (new FrameTag ());
registerTag (new HeadingTag ());
registerTag (new ImageTag ());
registerTag (new InputTag ());
registerTag (new JspTag ());
registerTag (new LabelTag ());
registerTag (new LinkTag ());
registerTag (new MetaTag ());
registerTag (new ObjectTag ());
registerTag (new OptionTag ());
registerTag (new ParagraphTag ());
registerTag (new ProcessingInstructionTag ());
registerTag (new ScriptTag ());
registerTag (new SelectTag ());
registerTag (new StyleTag ());
registerTag (new TableColumn ());
registerTag (new TableHeader ());
registerTag (new TableRow ());
registerTag (new TableTag ());
registerTag (new TextareaTag ());
registerTag (new TitleTag ());
registerTag (new Div ());
registerTag (new Span ());
registerTag (new BodyTag ());
registerTag (new HeadTag ());
registerTag (new Html ());
return (this);
}
/**
* Get the object that is cloned to generate text nodes.
* @return The prototype for {@link Text} nodes.
* @see #setTextPrototype
*/
public Text getTextPrototype ()
{
return (mText);
}
/**
* Set the object to be used to generate text nodes.
* @param text The prototype for {@link Text} nodes.
* If <code>null</code> the prototype is set to the default
* ({@link TextNode}).
* @see #getTextPrototype
*/
public void setTextPrototype (Text text)
{
if (null == text)
mText = new TextNode (null, 0, 0);
else
mText = text;
}
/**
* Get the object that is cloned to generate remark nodes.
* @return The prototype for {@link Remark} nodes.
* @see #setRemarkPrototype
*/
public Remark getRemarkPrototype ()
{
return (mRemark);
}
/**
* Set the object to be used to generate remark nodes.
* @param remark The prototype for {@link Remark} nodes.
* If <code>null</code> the prototype is set to the default
* ({@link RemarkNode}).
* @see #getRemarkPrototype
*/
public void setRemarkPrototype (Remark remark)
{
if (null == remark)
mRemark = new RemarkNode (null, 0, 0);
else
mRemark = remark;
}
/**
* Get the object that is cloned to generate tag nodes.
* Clones of this object are returned from {@link #createTagNode} when no
* specific tag is found in the list of registered tags.
* @return The prototype for {@link Tag} nodes.
* @see #setTagPrototype
*/
public Tag getTagPrototype ()
{
return (mTag);
}
/**
* Set the object to be used to generate tag nodes.
* Clones of this object are returned from {@link #createTagNode} when no
* specific tag is found in the list of registered tags.
* @param tag The prototype for {@link Tag} nodes.
* If <code>null</code> the prototype is set to the default
* ({@link TagNode}).
* @see #getTagPrototype
*/
public void setTagPrototype (Tag tag)
{
if (null == tag)
mTag = new TagNode (null, 0, 0, null);
else
mTag = tag;
}
//
// NodeFactory interface
//
/**
* Create a new string node.
* @param page The page the node is on.
* @param start The beginning position of the string.
* @param end The ending position of the string.
* @return A text node comprising the indicated characters from the page.
*/
public Text createStringNode (Page page, int start, int end)
{
Text ret;
try
{
ret = (Text)(getTextPrototype ().clone ());
ret.setPage (page);
ret.setStartPosition (start);
ret.setEndPosition (end);
}
catch (CloneNotSupportedException cnse)
{
ret = new TextNode (page, start, end);
}
return (ret);
}
/**
* Create a new remark node.
* @param page The page the node is on.
* @param start The beginning position of the remark.
* @param end The ending positiong of the remark.
* @return A remark node comprising the indicated characters from the page.
*/
public Remark createRemarkNode (Page page, int start, int end)
{
Remark ret;
try
{
ret = (Remark)(getRemarkPrototype ().clone ());
ret.setPage (page);
ret.setStartPosition (start);
ret.setEndPosition (end);
}
catch (CloneNotSupportedException cnse)
{
ret = new RemarkNode (page, start, end);
}
return (ret);
}
/**
* Create a new tag node.
* Note that the attributes vector contains at least one element,
* which is the tag name (standalone attribute) at position zero.
* This can be used to decide which type of node to create, or
* gate other processing that may be appropriate.
* @param page The page the node is on.
* @param start The beginning position of the tag.
* @param end The ending positiong of the tag.
* @param attributes The attributes contained in this tag.
* @return A tag node comprising the indicated characters from the page.
*/
public Tag createTagNode (Page page, int start, int end, Vector attributes)
{
Attribute attribute;
String id;
Tag prototype;
Tag ret;
ret = null;
if (0 != attributes.size ())
{
attribute = (Attribute)attributes.elementAt (0);
id = attribute.getName ();
if (null != id)
{
try
{
id = id.toUpperCase (Locale.ENGLISH);
if (!id.startsWith ("/"))
{
if (id.endsWith ("/"))
id = id.substring (0, id.length () - 1);
prototype = (Tag)mBlastocyst.get (id);
if (null != prototype)
{
ret = (Tag)prototype.clone ();
ret.setPage (page);
ret.setStartPosition (start);
ret.setEndPosition (end);
ret.setAttributesEx (attributes);
}
}
}
catch (CloneNotSupportedException cnse)
{
// default to creating a generic one
}
}
}
if (null == ret)
{ // generate a generic node
try
{
ret = (Tag)getTagPrototype ().clone ();
ret.setPage (page);
ret.setStartPosition (start);
ret.setEndPosition (end);
ret.setAttributesEx (attributes);
}
catch (CloneNotSupportedException cnse)
{
ret = new TagNode (page, start, end, attributes);
}
}
return (ret);
}
}