package it.unimi.dsi.parser;
/*
* DSI utilities
*
* Copyright (C) 2005-2009 Sebastiano Vigna
*
* 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 program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
import it.unimi.dsi.fastutil.objects.Reference2ObjectArrayMap;
import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
import it.unimi.dsi.fastutil.objects.ReferenceArraySet;
import it.unimi.dsi.fastutil.objects.ReferenceSet;
import it.unimi.dsi.fastutil.objects.ReferenceSets;
import it.unimi.dsi.lang.MutableString;
import it.unimi.dsi.util.TextPattern;
import it.unimi.dsi.parser.callback.Callback;
/** A fast, lightweight, on-demand (X)HTML parser.
*
* <p>The bullet parser has been written with two specific goals in mind:
* web crawling and targeted data extraction from massive web data sets.
* To be usable in such environments, a parser must obey a number of
* restrictions:
* <ul>
* <li>it should avoid excessive object creation (which, for instance,
* forbids a significant usage of Java strings);
* <li>it should tolerate invalid syntax and recover reasonably; in fact,
* it should never throw exceptions;
* <li>it should perform actual parsing only on a settable feature subset:
* there is no reason to parse the attributes of a <samp>P</samp>
* element while searching for links;
* <li>it should parse HTML as a <em>regular language</em>, and leave context-free
* properties (e.g., stack maintenance and repair) to suitably designed callbacks.
* </ul>
*
* <p>Thus, in fact the bullet parser is not a parser. It is a bunch of
* spaghetti code that analyses a stream of characters pretending that
* it is an (X)HTML document. It has a very defensive attitude against
* the stream character it is parsing, but at the same time it is
* forgiving with all typical (X)HTML mistakes.
*
* <p>The bullet parser is officially StringFree™.
* <a href="http://dsiutils.dsi.unimi.it/docs/it/unimi/dsi/lang/MutableString.html"><code>MutableString</code>s</a>
* are used for internal processing, and Java strings are used only to return attribute
* values. All internal maps are {@linkplain it.unimi.dsi.fastutil.objects.Reference2ObjectMap reference-based maps}
* from <a href="http://fastutil.dsi.unimi.it/"><samp>fastutil</samp></a>, which
* helps to accelerate further the parsing process.
*
* <h2>HTML data</h2>
*
* <p>The bullet parser uses attributes and methods of {@link it.unimi.dsi.parser.HTMLFactory},
* {@link it.unimi.dsi.parser.Element}, {@link it.unimi.dsi.parser.Attribute}
* and {@link it.unimi.dsi.parser.Entity}.
* Thus, for instance, whenever an element is to be passed around it is one
* of the shared objects contained in {@link it.unimi.dsi.parser.Element}
* (e.g., {@link it.unimi.dsi.parser.Element#BODY}).
*
* <h2>Callbacks</h2>
*
* <p>The result of the parsing process is the invocation of a callback.
* The {@linkplain it.unimi.dsi.parser.callback.Callback callback interface}
* of the bullet parser remembers closely SAX2, but it has some additional
* methods targeted at (X)HTML, such as {@link it.unimi.dsi.parser.callback.Callback#cdata(it.unimi.dsi.parser.Element,char[],int,int)},
* which returns characters found in a CDATA section (e.g., a stylesheet).
*
* <p>Each callback must configure the parser, by requesting to perform
* the analysis and the callbacks it requires. A callback that wants to
* extract and tokenise text, for instance, will certainly require
* {@link #parseText(boolean) parseText(true)}, but not {@link #parseTags(boolean) parseTags(true)}.
* On the other hand, a callback wishing to extract links will require
* to {@linkplain #parseAttribute(Attribute) parse selectively} certain attribute types.
*
* <p>A more precise description follows.
*
* <h2>Writing callbacks</h2>
*
* <p>The first important issue is what has to be required to the parser. A newly
* created parser does not invoke any callback. It is up to every callback
* to add features so that it can do its job. Remember that since many
* callbacks can be {@linkplain it.unimi.dsi.parser.callback.ComposedCallbackBuilder composed},
* you must always <em>add</em> features, never <em>remove</em> them, and moreover
* your callbacks must be ready to be invoked with features they did not
* request (e.g., attribute types added by another callback).
*
* <p>The following parse features
* may be configured; most of them are just boolean features, a.k.a. flags:
* unless otherwise specified, by default all flags are set to false (e.g., by
* the default the parser will <em>not</em> parse tags):
* <ul>
* <li><em>tags</em> ({@link #parseTags(boolean)} method): whether tags
* should be parsed;
* <li><em>attributes</em> ({@link #parseAttributes(boolean)} and
* {@link #parseAttribute(Attribute) methods)}:
* whether attributes should be parsed (of course, setting this flag is useless
* if you are not parsing tags); note that setting this flag will just
* activate the attribute parsing feature, but you must also
* {@linkplain #parseAttribute(Attribute) register} every attribute
* whose value you want to obtain.
* <li><em>text</em> ({@link #parseText(boolean)}method): whether text
* should be parsed; if this flag is set, the parser will call the
* {@link it.unimi.dsi.parser.callback.Callback#characters(char[], int, int, boolean)}
* method for every text chunk found.
* <li><em>CDATA sections</em> ({@link #parseCDATA(boolean)}method): whether CDATA
* sections (stylesheets & scripts)
* should be parsed; if this flag is set, the parser will call the
* {@link it.unimi.dsi.parser.callback.Callback#cdata(Element,char[],int,int)}
* method for every CDATA section found.
* </ul>
*
* <h2>Invoking the parser</h2>
*
* <p>After {@linkplain #setCallback(Callback) setting the parser callback},
* you just call {@link #parse(char[], int, int)}.
*/
public class BulletParser {
private static final boolean DEBUG = false;
/** Scanning text.. */
protected static final int STATE_TEXT = 0;
/** Scanning attribute name/value pairs. */
protected static final int STATE_BEFORE_START_TAG_NAME = 1;
/** Scanning a closing tag. */
protected static final int STATE_BEFORE_END_TAG_NAME = 2;
/** Scanning attribute name/value pairs. */
protected static final int STATE_IN_START_TAG = 3;
/** Scanning a closing tag. */
protected static final int STATE_IN_END_TAG = 4;
/** The maximum Unicode value accepted for a numeric entity. */
protected static final int MAX_ENTITY_VALUE = 65535;
/** The base for non-decimal entity. */
protected static final int HEXADECIMAL = 16;
/** The maximum number of digits of a hexadecimal numeric entity. */
protected static final int MAX_HEX_ENTITY_LENGTH = 8;
/** The maximum number of digits of a decimal numeric entity. */
protected static final int MAX_DEC_ENTITY_LENGTH = 9;
/** Closing tag for a script element. */
protected static final TextPattern SCRIPT_CLOSE_TAG_PATTERN = new TextPattern( "</script>", TextPattern.CASE_INSENSITIVE );
/** Closing tag for a style element. */
protected static final TextPattern STYLE_CLOSE_TAG_PATTERN = new TextPattern( "</style>", TextPattern.CASE_INSENSITIVE );
/** An array containing the non-space whitespace. */
protected static final char[] NONSPACE_WHITESPACE = { '\n', '\r', '\t' };
/** An array, parallel to {@link #NONSPACE_WHITESPACE}, containing spaces. */
protected static final char[] SPACE = { ' ', ' ', ' ' };
/** Closed comment. It should be "-->", but mistakes are common. */
protected static final TextPattern CLOSED_COMMENT = new TextPattern( "->" );
/** Closed ASP or similar tag. */
protected static final TextPattern CLOSED_PERCENT = new TextPattern( "%>" );
/** Closed processing instruction. */
protected static final TextPattern CLOSED_PIC = new TextPattern( "?>" );
/** Closed section (conditional, etc.). */
protected static final TextPattern CLOSED_SECTION = new TextPattern( "]>" );
/** Closed section (conditional, CDATA, etc.). */
protected static final TextPattern CLOSED_CDATA = new TextPattern( "]]>" );
/** TODO: what is this?. */
//protected static final TextPattern CLOSED_BOH = new TextPattern( "!>" );
/** The parsing factory used by this parser. */
public final ParsingFactory factory;
/** The callback of this parser. */
protected Callback callback;
/** A map from attributes to attribute values. */
protected Reference2ObjectMap<Attribute,MutableString> attrMap;
/** Whether we should invoke the text handler. */
protected boolean parseText;
/** Whether we should invoke the CDATA section handler. */
protected boolean parseCDATA;
/** Whether we should parse tags. */
protected boolean parseTags;
/** Whether we should parse attributes. */
protected boolean parseAttributes;
/**
* The subset of attributes whose values will be actually parsed (if, of
* course, {@link #parseAttributes}is true).
*/
protected ReferenceArraySet<Attribute> parsedAttrs = new ReferenceArraySet<Attribute>();
/**
* An externally visible, immutable subset of attributes whose values will
* be actually parsed.
*/
public ReferenceSet<Attribute> parsedAttributes = ReferenceSets.unmodifiable( parsedAttrs );
/** The character represented by the last scanned entity. */
protected char lastEntity;
/** Creates a new bullet parser. */
public BulletParser( final ParsingFactory factory ) {
this.factory = factory;
}
/** Creates a new bullet parser using the default factory {@link HTMLFactory#INSTANCE}. */
public BulletParser() {
this( HTMLFactory.INSTANCE );
}
/**
* Returns whether this parser will invoke the text handler.
*
* @return whether this parser will invoke the text handler.
* @see #parseText(boolean)
*/
public boolean parseText() {
return parseText;
}
/**
* Sets the text handler flag.
*
* @param parseText
* the new value.
* @return this parser.
*/
public BulletParser parseText( final boolean parseText ) {
this.parseText = parseText;
return this;
}
/**
* Returns whether this parser will invoke the CDATA-section handler.
*
* @return whether this parser will invoke the CDATA-section handler.
* @see #parseCDATA(boolean)
*/
public boolean parseCDATA() {
return parseCDATA;
}
/**
* Sets the CDATA-section handler flag.
*
* @param parseCDATA
* the new value.
* @return this parser.
*/
public BulletParser parseCDATA( final boolean parseCDATA ) {
this.parseCDATA = parseCDATA;
return this;
}
/**
* Returns whether this parser will parse tags and invoke element handlers.
*
* @return whether this parser will parse tags and invoke element handlers.
* @see #parseTags(boolean)
*/
public boolean parseTags() {
return parseTags;
}
/**
* Sets whether this parser will parse tags and invoke element handlers.
*
* @param parseTags
* the new value.
* @return this parser.
*/
public BulletParser parseTags( final boolean parseTags ) {
this.parseTags = parseTags;
return this;
}
/**
* Returns whether this parser will parse attributes.
*
* @return whether this parser will parse attributes.
* @see #parseAttributes(boolean)
*/
public boolean parseAttributes() {
return parseAttributes;
}
/**
* Sets the attribute parsing flag.
*
* @param parseAttributes
* the new value for the flag.
* @return this parser.
*/
public BulletParser parseAttributes( final boolean parseAttributes ) {
this.parseAttributes = parseAttributes;
return this;
}
/**
* Adds the given attribute to the set of attributes to be parsed.
*
* @param attribute
* an attribute that should be parsed.
* @throws IllegalStateException
* if {@link #parseAttributes(boolean) parseAttributes(true)}
* has not been invoked on this parser.
* @return this parser.
*/
public BulletParser parseAttribute( final Attribute attribute ) {
parsedAttrs.add( attribute );
return this;
}
/** Sets the callback for this parser, resetting at the same time all parsing flags.
*
* @param callback the new callback.
* @return this parser.
*/
public BulletParser setCallback( final Callback callback ) {
this.callback = callback;
parseCDATA = parseText = parseAttributes = parseTags = false;
parsedAttrs.clear();
callback.configure( this );
return this;
}
/** Returns the character corresponding to a given entity name.
*
* @param name the name of an entity.
* @return the character corresponding to the entity, or an ASCII NUL if no entity with that name was found.
*/
protected char entity2Char( final MutableString name ) {
final Entity e = factory.getEntity( name );
return e == null ? (char)0 : e.character;
}
/** Searches for the end of an entity.
*
* <P>This method will search for the end of an entity starting at the given offset (the offset
* must correspond to the ampersand).
*
* <P>Real-world HTML pages often contain hundreds of misplaced ampersands, due to the
* unfortunate idea of using the ampersand as query separator (<em>please</em> use the comma
* in new code!). All such ampersand should be specified as <samp>&</samp>.
* If named entities are delimited using a transition
* from alphabetical to non-alphabetical characters, we can easily get false positives. If the parameter
* <code>loose</code> is false, named entities can be delimited only by whitespace or by a comma.
*
* @param a a character array containing the entity.
* @param offset the offset at which the entity starts (the offset must point at the ampersand).
* @param length an upper bound to the maximum returned position.
* @param loose if true, named entities can be terminated by any non-alphabetical character
* (instead of whitespace or comma).
* @param entity a support mutable string used to query {@link ParsingFactory#getEntity(MutableString)}.
* @return the position of the last character of the entity, or -1 if no entity was found.
*/
protected int scanEntity( final char[] a, final int offset, final int length, final boolean loose, final MutableString entity ) {
int i, c = 0;
String tmpEntity;
if ( length < 2 ) return -1;
if ( a[ offset + 1 ] == '#' ) {
if ( length > 2 && a[ offset + 2 ] == 'x' ) {
for( i = 3; i < length && i < MAX_HEX_ENTITY_LENGTH && Character.digit( a[ i + offset ], HEXADECIMAL ) != -1; i++ );
tmpEntity = new String( a, offset + 3, i - 3 );
if ( i != 3 ) c = Integer.parseInt( tmpEntity, HEXADECIMAL );
}
else {
for( i = 2; i < length && i < MAX_DEC_ENTITY_LENGTH && Character.isDigit( a[ i + offset ] ); i++ );
tmpEntity = new String( a, offset + 2, i - 2 );
if ( i != 2 ) c = Integer.parseInt( tmpEntity );
}
if ( c > 0 && c < MAX_ENTITY_VALUE ) {
lastEntity = (char)c;
if ( i < length && a[ i + offset ] == ';' ) i++;
return i + offset;
}
}
else {
if ( Character.isLetter( a[ offset + 1 ] ) ) {
for( i = 2; i < length && Character.isLetterOrDigit( a[ offset + i ] ); i++ );
if ( i != 1 && ( loose || ( i < length && ( Character.isWhitespace( a[ offset + i ] ) || a[ offset + i ] == ';' ) ) ) && ( lastEntity = entity2Char( entity.length( 0 ).append( a, offset + 1, i - 1 ) ) ) != 0 ) {
if ( i < length && a[ i + offset ] == ';' ) i++;
return i + offset;
}
}
}
return -1;
}
/**
* Replaces entities with the corresponding characters.
*
* <P>This method will modify the mutable string <code>s</code> so that all legal occurrences
* of entities are replaced by the corresponding character.
*
* @param s a mutable string whose entities will be replaced by the corresponding characters.
* @param entity a support mutable string used by {@link #scanEntity(char[], int, int, boolean, MutableString)}.
* @param loose a parameter that will be passed to {@link #scanEntity(char[], int, int, boolean, MutableString)}.
*/
protected void replaceEntities( final MutableString s, final MutableString entity, final boolean loose ) {
final char[] a = s.array();
int length = s.length();
/* We examine the string *backwards*, so that i is always a valid index. */
int i = length, j;
while( i-- > 0 )
if ( a[ i ] == '&' && ( j = scanEntity( a, i, length - i, loose, entity ) ) != -1 )
length = s.replace( i, j, lastEntity ).length();
}
/** Handles markup.
*
* @param text the text.
* @param pos the first character in the markup after <samp><!</samp>.
* @param end the end of <code>text</code>.
* @return the position of the first character after the markup.
*/
protected int handleMarkup( final char[] text, int pos, final int end ) {
// A markup instruction (doctype, comment, etc.).
switch( text[ ++pos ] ) {
case 'D':
case 'd':
// DOCTYPE
while( pos < end && text[ pos++ ] != '>' );
break;
case '-':
// comment
if ( ( pos = CLOSED_COMMENT.search( text, pos, end ) ) == -1 ) pos = end;
else pos += CLOSED_COMMENT.length();
break;
default:
if ( pos < end - 6 &&
text[ pos ] == '[' && text[ pos + 1 ] == 'C' && text[ pos + 2 ] == 'D' && text[ pos + 3 ] == 'A' && text[ pos + 4 ] == 'T' && text[ pos + 5 ] == 'A' && text[ pos + 6 ] == '[' ) {
// CDATA section
final int last = CLOSED_CDATA.search( text, pos, end );
if ( parseCDATA ) callback.cdata( null, text, pos + 7, ( last == -1 ? end : last ) - pos - 7 );
pos = last == -1 ? end : last + CLOSED_CDATA.length();
}
// Generic markup
else while( pos < end && text[ pos++ ] != '>' );
break;
}
return pos;
}
/** Handles processing instruction, ASP tags etc.
*
* @param text the text.
* @param pos the first character in the markup after <samp><%</samp>.
* @param end the end of <code>text</code>.
* @return the position of the first character after the processing instruction.
*/
protected int handleProcessingInstruction( final char[] text, int pos, final int end ) {
switch( text[ ++pos ] ) {
case '%':
if ( ( pos = CLOSED_PERCENT.search( text, pos, end ) ) == -1 ) pos = end;
else pos += CLOSED_PERCENT.length();
break;
case '?':
if ( ( pos = CLOSED_PIC.search( text, pos, end ) ) == -1 ) pos = end;
else pos += CLOSED_PIC.length();
break;
case '[':
if ( ( pos = CLOSED_SECTION.search( text, pos, end ) ) == -1 ) pos = end;
else pos += CLOSED_SECTION.length();
break;
default:
// Generic markup
while( pos < end && text[ pos++ ] != '>' );
break;
}
return pos;
}
/**
* Analyze the text document to extract information.
*
* @param text a <code>char</code> array of text to be parsed.
*/
public void parse( final char[] text ) {
parse( text, 0, text.length );
}
/**
* Analyze the text document to extract information.
*
* @param text a <code>char</code> array of text to be parsed.
* @param offset the offset in the array from which the parsing will begin.
* @param length the number of characters to be parsed.
*/
public void parse( final char[] text, final int offset, final int length ) {
MutableString tagElemTypeName = new MutableString();
MutableString attrName = new MutableString();
MutableString attrValue = new MutableString();
MutableString entity = new MutableString();
MutableString characters = new MutableString();
/* During the analysis of attribute we need a separator for values */
char delim;
/* The current character */
char currChar;
/* The state of the switch */
int state;
/* Others integer values used in the parsing process */
int start, k;
/* This boolean is set true if we have words to handle */
boolean flowBroken = false, parseCurrAttr;
/* The current element. */
Element currentElement;
/* The current attribute object */
Attribute currAttr = null;
attrMap = new Reference2ObjectArrayMap<Attribute,MutableString>( 16 );
callback.startDocument();
tagElemTypeName.length( 0 );
attrName.length( 0 );
attrValue.length( 0 );
entity.length( 0 );
state = STATE_TEXT;
currentElement = null;
final int end = offset + length;
int pos = offset;
/* This is the main loop. */
while ( pos < end ) {
switch( state ) {
case STATE_TEXT:
currChar = text[ pos ];
if ( currChar == '&' ) {
// We handle both the case of an entity, and that of a stray '&'.
if ( ( k = scanEntity( text, pos, end - pos, true, entity ) ) == -1 ) {
currChar = '&';
pos++;
}
else {
currChar = lastEntity;
pos = k;
if ( DEBUG ) System.err.println( "Entity at: " + pos + " end of entity: " + k + " entity: " + entity + " char: " + currChar );
}
if ( parseText ) characters.append( currChar );
continue;
}
// No tags can happen later than end - 2.
if ( currChar != '<' || pos >= end - 2 ) {
if ( parseText ) characters.append( currChar );
pos++;
continue;
}
switch( text[ ++pos ] ) {
case '!':
pos = handleMarkup( text, pos, end );
break;
case '%':
case '?':
pos = handleProcessingInstruction( text, pos, end );
break;
default:
// Actually a tag. Note that we allow for </> and that we skip false positives
// due to sloppy HTML writing (e.g., "<-- hello! -->" ).
if ( Character.isLetter( text[ pos ] ) ) state = STATE_BEFORE_START_TAG_NAME;
else if ( text[ pos ] == '/' && ( Character.isLetter( text[ pos + 1 ] ) || text[ pos + 1 ] == '>' ) ) {
state = STATE_BEFORE_END_TAG_NAME;
pos++;
}
else {
// Not really a tag.
if ( parseText ) characters.append( '<' );
continue;
}
break;
}
if ( parseText && characters.length() != 0 ) {
callback.characters( characters.array(), 0, characters.length(), flowBroken );
characters.length( 0 );
}
flowBroken = false;
break;
case STATE_BEFORE_START_TAG_NAME:
case STATE_BEFORE_END_TAG_NAME:
// Let's get the name.
tagElemTypeName.length( 0 );
for( start = pos; pos < end && ( Character.isLetterOrDigit( text[ pos ] ) || text[ pos ] == ':' || text[ pos ] == '_' ||text[ pos ] == '-' || text[ pos ] == '.' ); pos++ );
tagElemTypeName.append( text, start, pos - start );
tagElemTypeName.toLowerCase();
currentElement = factory.getElement( tagElemTypeName );
if ( DEBUG ) System.err.println( ( state == STATE_BEFORE_START_TAG_NAME ? "Opening" : "Closing" ) + " tag for " + tagElemTypeName + " (element: " + currentElement+ ")" );
if ( currentElement != null && currentElement.breaksFlow ) flowBroken = true;
while( pos < end && Character.isWhitespace( text[ pos ] ) ) pos++;
state = state == STATE_BEFORE_START_TAG_NAME ? STATE_IN_START_TAG : STATE_IN_END_TAG;
break;
case STATE_IN_START_TAG:
currChar = text[ pos ];
if ( currChar != '>' && ( currChar != '/' || pos == end - 1 || text[ pos + 1 ] != '>' ) ) {
// We got attributes.
if ( Character.isLetter( currChar ) ) {
parseCurrAttr = false;
attrName.length( 0 );
for( start = pos; pos < end && ( Character.isLetter( text[ pos ] ) || text[ pos ] == '-' ); pos++ );
if ( currentElement != null && parseAttributes ) {
attrName.append( text, start, pos - start );
attrName.toLowerCase();
if ( DEBUG ) System.err.println( "Got attribute named \"" + attrName + "\"" );
currAttr = factory.getAttribute( attrName );
parseCurrAttr = parsedAttrs.contains( currAttr );
}
// Skip whitespace
while ( pos < end && Character.isWhitespace( text[ pos ] ) ) pos++;
if ( pos == end ) break;
if ( text[ pos ] != '=' ) {
// We found an attribute without explicit value.
// TODO: can we avoid another string?
if ( parseCurrAttr ) attrMap.put( currAttr, new MutableString( currAttr.name ) );
break;
}
pos++;
while ( pos < end && Character.isWhitespace( text[ pos ] ) ) pos++;
if ( pos == end ) break;
attrValue.length( 0 );
if ( pos < end && ( ( delim = text[ pos ] ) == '"' || ( delim = text[ pos ] ) == '\'' ) ) {
// An attribute value with delimiters.
for( start = ++pos; pos < end && text[ pos ] != delim; pos++ );
if ( parseCurrAttr ) attrValue.append( text, start, pos - start ).replace( NONSPACE_WHITESPACE, SPACE );
if ( pos < end ) pos++;
}
else {
// An attribute value without delimiters. Due to very common errors, we
// gather characters up to the first occurrence of whitespace or '>'.
for( start = pos; pos < end && !Character.isWhitespace( text[ pos ] ) && text[ pos ] != '>'; pos++ );
if ( parseCurrAttr ) attrValue.append( text, start, pos - start );
}
if ( parseCurrAttr ) {
replaceEntities( attrValue, entity, false );
attrMap.put( currAttr, attrValue.copy() );
if ( DEBUG ) System.err.println( "Attribute value: \"" + attrValue + "\"" );
}
// Skip whitespace
while ( pos < end && Character.isWhitespace( text[ pos ] ) ) pos++;
}
else {
// It's a mess. Our only reasonable chance is to try to resync on the first
// whitespace, or alternatively to get to the end of the tag.
do pos++; while ( pos < end && text[ pos ] != '>' && ! Character.isWhitespace( text[ pos ] ) );
// Skip whitespace
while ( pos < end && Character.isWhitespace( text[ pos ] ) ) pos++;
continue;
}
}
else {
if ( parseTags && ! callback.startElement( currentElement, attrMap ) ) break;
if ( attrMap != null ) attrMap.clear();
if ( currentElement == Element.SCRIPT || currentElement == Element.STYLE ) {
final TextPattern pattern = currentElement == Element.SCRIPT ? SCRIPT_CLOSE_TAG_PATTERN : STYLE_CLOSE_TAG_PATTERN;
start = pos + 1;
pos = pattern.search( text, start, end );
if ( pos == -1 ) pos = end;
if ( parseText ) callback.cdata( currentElement, text, start, pos - start );
if ( pos < end ) {
if ( parseTags ) callback.endElement( currentElement );
pos += pattern.length();
}
}
else pos += currChar == '/' ? 2 : 1;
state = STATE_TEXT;
}
break;
case STATE_IN_END_TAG:
while ( pos < end && text[ pos ] != '>' ) pos++;
if ( parseTags && currentElement != null && ! callback.endElement( currentElement ) ) break;
state = STATE_TEXT;
pos++;
break;
default:
}
}
// We do what we can to invoke tag handlers in case of a truncated text.
if ( state == STATE_IN_START_TAG && parseTags && currentElement != null ) callback.startElement( currentElement, attrMap );
if ( state == STATE_IN_END_TAG && parseTags && currentElement != null ) callback.endElement( currentElement );
if ( state == STATE_TEXT && parseText && characters.length() > 0 )
callback.characters( characters.array(), 0, characters.length(), flowBroken );
callback.endDocument();
}
}