src.au.id.jericho.lib.html.Element Maven / Gradle / Ivy
// Jericho HTML Parser - Java based library for analysing and manipulating HTML
// Version 1.5
// Copyright (C) 2004 Martin Jericho
// http://jerichohtml.sourceforge.net/
//
// 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.
// http://www.gnu.org/copyleft/lesser.html
//
// 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 au.id.jericho.lib.html;
import java.util.*;
/**
* Represents an HTML element,
* which encompasses the {@link StartTag}, an optional {@link EndTag} and all content in between.
*
* If the start tag has no corresponding end tag:
*
* -
* If the end tag is {@linkplain StartTag#isEndTagOptional() optional}, the end of the element occurs at the
* start of the next tag that implicitly terminates this type of element.
*
-
* If the end tag is {@linkplain StartTag#isEndTagForbidden() forbidden}, the element spans only the start tag.
*
-
* If the end tag is {@linkplain StartTag#isEndTagRequired() required}, the source HTML is invalid and the
* element spans only the start tag.
* No attempt is made by this library to determine how user agents might interpret invalid HTML.
*
* Note that this behaviour has changed since version 1.0, which treated optional end tags the same as required end tags.
*
* Created using the {@link Segment#findAllElements(String name)} or {@link StartTag#getElement()} method.
*
* See also the XML 1.0 specification for elements.
*
* @see StartTag
*/
public final class Element extends Segment {
private StartTag startTag;
private EndTag endTag=null;
Element(Source source, StartTag startTag, EndTag endTag) {
super(source, startTag.begin, endTag==null ? startTag.end : endTag.end);
this.startTag=startTag;
this.endTag=(endTag==null || endTag.length()==0) ? null : endTag;
}
/**
* Returns the {@linkplain #getContent() content} text of the element.
* @return the content text of the element, or null if the element is {@linkplain #isEmpty() empty}.
*/
public String getContentText() {
return isEmpty() ? null : source.subSequence(startTag.end,getContentEnd()).toString();
}
/**
* Returns the segment representing the content of the element.
*
* This segment spans between the end of the start tag and the start of the end tag.
* If the end tag is not present, the content reaches to the end of the element.
*
* The returned segment is newly created with every call to this method.
*
* Note that before version 1.5 this method returned null if the element was {@linkplain #isEmpty() empty},
* whereas now a zero-length segment is returned.
*
* @return the segment representing the content of the element, guaranteed not null.
*/
public Segment getContent() {
return new Segment(source,startTag.end,getContentEnd());
}
/**
* Returns the start tag of the element.
* @return the start tag of the element.
*/
public StartTag getStartTag() {
return startTag;
}
/**
* Returns the end tag of the element.
*
* If the element has no end tag this method returns null.
*
* @return the end tag of the element, or null if the element has no end tag.
*/
public EndTag getEndTag() {
return endTag;
}
/**
* Returns the {@linkplain StartTag#getName() name} of the StartTag of this element.
* @return the name of the StartTag of this element.
*/
public String getName() {
return startTag.getName();
}
/**
* Indicates whether the element is empty.
*
* The representation of an empty element is either a start tag immediately followed by an end tag,
* or an {@linkplain StartTag#isEmptyElementTag() empty-element tag}.
*
* @return true if the element is empty, otherwise false.
*/
public boolean isEmpty() {
return startTag.end==getContentEnd();
}
/**
* Indicates whether the element is an empty element tag.
* This is signified by the characters "/>" at the end of the start tag and the absence of an end tag.
* Note that not every {@linkplain #isEmpty() empty} element is an empty element tag.
*
* @return true if the element is an empty element tag, otherwise false.
* @see #isEmpty()
*/
public boolean isEmptyElementTag() {
return startTag.isEmptyElementTag();
}
/**
* Indicates whether an element with the given name is a
* block element according to the
* HTML 4.01 Transitional DTD.
*
* A brief description of the difference between block and inline elements is given in the HTML 4.01
* Specification section 7.5.3.
*
* @return true if an element with the given name is a block element, otherwise false.
*/
public static boolean isBlock(String name) {
return Tag.isBlock(name);
}
/**
* Indicates whether an element with the given name is an
* inline element according to the
* HTML 4.01 Transitional DTD.
*
* A brief description of the difference between block and inline elements is given in the HTML 4.01
* Specification section 7.5.3.
*
* @return true if an element with the given name is an inline element, otherwise false.
*/
public static boolean isInline(String name) {
return Tag.isInline(name);
}
/**
* Returns the attributes specified in this element's start tag.
*
* This is equivalent to {@link StartTag#getAttributes() getStartTag().getAttributes()}
*
* @return the attributes specified in this element's start tag.
* @see StartTag#getAttributes()
*/
public Attributes getAttributes() {
return getStartTag().getAttributes();
}
/**
* Returns the {@link FormControl} defined by this element.
* @return the {@link FormControl} defined by this element, or null if it is not a control.
*/
public FormControl getFormControl() {
return FormControl.construct(this);
}
public String getDebugInfo() {
return "Element "+super.getDebugInfo()+": "+startTag.getDebugInfo()+"-"+(endTag==null ? "(no end tag)" : endTag.getDebugInfo());
}
protected int getContentEnd() {
return endTag!=null ? endTag.begin : end;
}
}