| /* Parser.java -- HTML parser |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package javax.swing.text.html.parser; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| import javax.swing.text.ChangedCharSetException; |
| import javax.swing.text.SimpleAttributeSet; |
| |
| /* |
| * FOR DEVELOPERS: To avoid regression, please run the package test |
| * textsuite/javax.swing.text.html.parser/AllParserTests after your |
| * modifications. |
| */ |
| |
| /** |
| * <p>A simple error-tolerant HTML parser that uses a DTD document |
| * to access data on the possible tokens, arguments and syntax.</p> |
| * <p> The parser reads an HTML content from a Reader and calls various |
| * notifying methods (which should be overridden in a subclass) |
| * when tags or data are encountered.</p> |
| * <p>Some HTML elements need no opening or closing tags. The |
| * task of this parser is to invoke the tag handling methods also when |
| * the tags are not explicitly specified and must be supposed using |
| * information, stored in the DTD. |
| * For example, parsing the document |
| * <p><table><tr><td>a<td>b<td>c</tr> <br> |
| * will invoke exactly the handling methods exactly in the same order |
| * (and with the same parameters) as if parsing the document: <br> |
| * <em><html><head></head><body><table>< |
| * tbody></em><tr><td>a<em></td></em><td>b<em> |
| * </td></em><td>c<em></td></tr></em>< |
| * <em>/tbody></table></body></html></em></p> |
| * (supposed tags are given in italics). The parser also supports |
| * obsolete elements of HTML syntax.<p> |
| * </p> |
| * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) |
| */ |
| public class Parser |
| implements DTDConstants |
| { |
| /** |
| * The document template description that will be used to parse the documents. |
| */ |
| protected DTD dtd; |
| |
| /** |
| * The value of this field determines whether or not the Parser will be |
| * strict in enforcing SGML compatibility. The default value is false, |
| * stating that the parser should do everything to parse and get at least |
| * some information even from the incorrectly written HTML input. |
| */ |
| protected boolean strict; |
| |
| /** |
| * The package level reference to the working HTML parser in this |
| * implementation. |
| */ |
| final gnu.javax.swing.text.html.parser.support.Parser gnu; |
| |
| /** |
| * Creates a new parser that uses the given DTD to access data on the |
| * possible tokens, arguments and syntax. There is no single - step way |
| * to get a default DTD; you must either refer to the implementation - |
| * specific packages, write your own DTD or obtain the working instance |
| * of parser in other way, for example, by calling |
| * {@link javax.swing.text.html.HTMLEditorKit#getParser() }. |
| * @param a_dtd A DTD to use. |
| */ |
| public Parser(DTD a_dtd) |
| { |
| dtd = a_dtd; |
| |
| final Parser j = this; |
| |
| gnu = |
| new gnu.javax.swing.text.html.parser.support.Parser(dtd) |
| { |
| protected final void handleComment(char[] comment) |
| { |
| j.handleComment(comment); |
| } |
| |
| protected final void handleEOFInComment() |
| { |
| j.handleEOFInComment(); |
| } |
| |
| protected final void handleEmptyTag(TagElement tag) |
| throws javax.swing.text.ChangedCharSetException |
| { |
| j.handleEmptyTag(tag); |
| } |
| |
| protected final void handleStartTag(TagElement tag) |
| { |
| j.handleStartTag(tag); |
| } |
| |
| protected final void handleEndTag(TagElement tag) |
| { |
| j.handleEndTag(tag); |
| } |
| |
| protected final void handleError(int line, String message) |
| { |
| j.handleError(line, message); |
| } |
| |
| protected final void handleText(char[] text) |
| { |
| j.handleText(text); |
| } |
| |
| protected final void handleTitle(char[] title) |
| { |
| j.handleTitle(title); |
| } |
| |
| protected final void markFirstTime(Element element) |
| { |
| j.markFirstTime(element); |
| } |
| |
| protected final void startTag(TagElement tag) |
| throws ChangedCharSetException |
| { |
| j.startTag(tag); |
| } |
| |
| protected final void endTag(boolean omitted) |
| { |
| j.endTag(omitted); |
| } |
| |
| protected TagElement makeTag(Element element) |
| { |
| return j.makeTag(element); |
| } |
| |
| protected TagElement makeTag(Element element, boolean isSupposed) |
| { |
| return j.makeTag(element, isSupposed); |
| } |
| }; |
| } |
| |
| /** |
| * Parse the HTML text, calling various methods in response to the |
| * occurence of the corresponding HTML constructions. |
| * @param reader The reader to read the source HTML from. |
| * @throws IOException If the reader throws one. |
| */ |
| public synchronized void parse(Reader reader) |
| throws IOException |
| { |
| gnu.parse(reader); |
| } |
| |
| /** |
| * Parses DTD markup declaration. Currently returns without action. |
| * @return null. |
| * @throws java.io.IOException |
| */ |
| public String parseDTDMarkup() |
| throws IOException |
| { |
| return gnu.parseDTDMarkup(); |
| } |
| |
| /** |
| * Parse DTD document declarations. Currently only parses the document |
| * type declaration markup. |
| * @param strBuff |
| * @return true if this is a valid DTD markup declaration. |
| * @throws IOException |
| */ |
| protected boolean parseMarkupDeclarations(StringBuffer strBuff) |
| throws IOException |
| { |
| return gnu.parseMarkupDeclarations(strBuff); |
| } |
| |
| /** |
| * Get the attributes of the current tag. |
| * @return The attribute set, representing the attributes of the current tag. |
| */ |
| protected SimpleAttributeSet getAttributes() |
| { |
| return gnu.getAttributes(); |
| } |
| |
| /** |
| * Get the number of the document line being parsed. |
| * @return The current line. |
| */ |
| protected int getCurrentLine() |
| { |
| return gnu.hTag.where.beginLine; |
| } |
| |
| /** |
| * Get the current position in the document being parsed. |
| * @return The current position. |
| */ |
| protected int getCurrentPos() |
| { |
| return gnu.hTag.where.startPosition; |
| } |
| |
| /** |
| * The method is called when the HTML end (closing) tag is found or if |
| * the parser concludes that the one should be present in the |
| * current position. The method is called immediatly |
| * before calling the handleEndTag(). |
| * @param omitted True if the tag is no actually present in the document, |
| * but is supposed by the parser (like </html> at the end of the |
| * document). |
| */ |
| protected void endTag(boolean omitted) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * Invokes the error handler. The default method in this implementation |
| * finally delegates the call to handleError, also providing the number of the |
| * current line. |
| */ |
| protected void error(String msg) |
| { |
| gnu.error(msg); |
| } |
| |
| /** |
| * Invokes the error handler. The default method in this implementation |
| * finally delegates the call to error (msg+": '"+invalid+"'"). |
| */ |
| protected void error(String msg, String invalid) |
| { |
| gnu.error(msg, invalid); |
| } |
| |
| /** |
| * Invokes the error handler. The default method in this implementation |
| * finally delegates the call to error (parm1+" "+ parm2+" "+ parm3). |
| */ |
| protected void error(String parm1, String parm2, String parm3) |
| { |
| gnu.error(parm1, parm2, parm3); |
| } |
| |
| /** |
| * Invokes the error handler. The default method in this implementation |
| * finally delegates the call to error |
| * (parm1+" "+ parm2+" "+ parm3+" "+ parm4). |
| */ |
| protected void error(String parm1, String parm2, String parm3, String parm4) |
| { |
| gnu.error(parm1, parm2, parm3, parm4); |
| } |
| |
| /** |
| * In this implementation, this is never called and returns without action. |
| */ |
| protected void flushAttributes() |
| { |
| gnu.flushAttributes(); |
| } |
| |
| /** |
| * Handle HTML comment. The default method returns without action. |
| * @param comment The comment being handled |
| */ |
| protected void handleComment(char[] comment) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * This is additionally called in when the HTML content terminates |
| * without closing the HTML comment. This can only happen if the |
| * HTML document contains errors (for example, the closing --;gt is |
| * missing. The default method calls the error handler. |
| */ |
| protected void handleEOFInComment() |
| { |
| gnu.error("Unclosed comment"); |
| } |
| |
| /** |
| * Handle the tag with no content, like <br>. The method is |
| * called for the elements that, in accordance with the current DTD, |
| * has an empty content. |
| * @param tag The tag being handled. |
| * @throws javax.swing.text.ChangedCharSetException |
| */ |
| protected void handleEmptyTag(TagElement tag) |
| throws ChangedCharSetException |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * The method is called when the HTML closing tag ((like </table>) |
| * is found or if the parser concludes that the one should be present |
| * in the current position. |
| * @param tag The tag being handled |
| */ |
| protected void handleEndTag(TagElement tag) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /* Handle error that has occured in the given line. */ |
| protected void handleError(int line, String message) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * The method is called when the HTML opening tag ((like <table>) |
| * is found or if the parser concludes that the one should be present |
| * in the current position. |
| * @param tag The tag being handled |
| */ |
| protected void handleStartTag(TagElement tag) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * Handle the text section. |
| * <p> For non-preformatted section, the parser replaces |
| * \t, \r and \n by spaces and then multiple spaces |
| * by a single space. Additionaly, all whitespace around |
| * tags is discarded. |
| * </p> |
| * <p> For pre-formatted text (inside TEXAREA and PRE), the parser preserves |
| * all tabs and spaces, but removes <b>one</b> bounding \r, \n or \r\n, |
| * if it is present. Additionally, it replaces each occurence of \r or \r\n |
| * by a single \n.</p> |
| * |
| * @param text A section text. |
| */ |
| protected void handleText(char[] text) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * Handle HTML <title> tag. This method is invoked when |
| * both title starting and closing tags are already behind. |
| * The passed argument contains the concatenation of all |
| * title text sections. |
| * @param title The title text. |
| */ |
| protected void handleTitle(char[] title) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * Constructs the tag from the given element. In this implementation, |
| * this is defined, but never called. |
| * @param element the base element of the tag. |
| * @return the tag |
| */ |
| protected TagElement makeTag(Element element) |
| { |
| return makeTag(element, false); |
| } |
| |
| /** |
| * Constructs the tag from the given element. |
| * @param element the tag base {@link javax.swing.text.html.parser.Element} |
| * @param isSupposed true if the tag is not actually present in the |
| * html input, but the parser supposes that it should to occur in |
| * the current location. |
| * @return the tag |
| */ |
| protected TagElement makeTag(Element element, boolean isSupposed) |
| { |
| return new TagElement(element, isSupposed); |
| } |
| |
| /** |
| * This is called when the tag, representing the given element, |
| * occurs first time in the document. |
| * @param element |
| */ |
| protected void markFirstTime(Element element) |
| { |
| // This default implementation does nothing. |
| } |
| |
| /** |
| * The method is called when the HTML opening tag ((like <table>) |
| * is found or if the parser concludes that the one should be present |
| * in the current position. The method is called immediately before |
| * calling the handleStartTag. |
| * @param tag The tag |
| */ |
| protected void startTag(TagElement tag) |
| throws ChangedCharSetException |
| { |
| // This default implementation does nothing. |
| } |
| } |