ext/java/nokogiri/Html4ElementDescription.java
package nokogiri;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import net.sourceforge.htmlunit.cyberneko.HTMLElements;
import org.jruby.Ruby;
import org.jruby.RubyClass;
import org.jruby.RubyObject;
import org.jruby.anno.JRubyClass;
import org.jruby.anno.JRubyMethod;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
/**
* Class for Nokogiri::HTML4::ElementDescription.
*
* @author Patrick Mahoney <pat@polycrystal.org>
*/
@JRubyClass(name = "Nokogiri::HTML4::ElementDescription")
public class Html4ElementDescription extends RubyObject
{
private static final long serialVersionUID = 1L;
private static final HTMLElements htmlElements_ = new HTMLElements();
/**
* Stores memoized hash of element -> list of valid subelements.
*/
static protected Map<Short, List<String>> subElements;
static
{
Map<Short, List<String>> _subElements =
new HashMap<Short, List<String>>();
subElements = Collections.synchronizedMap(_subElements);
}
protected HTMLElements.Element element;
public
Html4ElementDescription(Ruby runtime, RubyClass rubyClass)
{
super(runtime, rubyClass);
}
/**
* Lookup the list of sub elements of <code>code</code>. If not
* already stored, iterate through all elements to find valid
* subelements; save this list and return it.
*/
protected static List<String>
findSubElements(HTMLElements.Element elem)
{
List<String> subs = subElements.get(elem.code);
if (subs == null) {
subs = new ArrayList<String>();
/*
* A bit of a hack. NekoHtml source code shows that
* UNKNOWN is the highest value element. We cannot access
* the list of elements directly because it's protected.
*/
for (short c = 0; c < HTMLElements.UNKNOWN; c++) {
HTMLElements.Element maybe_sub = htmlElements_.getElement(c);
if (maybe_sub != null && maybe_sub.isParent(elem)) {
subs.add(maybe_sub.name);
}
}
subElements.put(elem.code, subs);
}
return subs;
}
@JRubyMethod(name = "[]", meta = true)
public static IRubyObject
get(ThreadContext context,
IRubyObject klazz, IRubyObject name)
{
// nekohtml will return an element even for invalid names, which breaks `test_fetch_nonexistent'
// see getElement() in HTMLElements.java
HTMLElements.Element elem = htmlElements_.getElement(name.asJavaString(), htmlElements_.NO_SUCH_ELEMENT);
if (elem == htmlElements_.NO_SUCH_ELEMENT) {
return context.nil;
}
Html4ElementDescription desc =
new Html4ElementDescription(context.getRuntime(), (RubyClass)klazz);
desc.element = elem;
return desc;
}
@JRubyMethod()
public IRubyObject
name(ThreadContext context)
{
return context.getRuntime().newString(element.name.toLowerCase());
}
@JRubyMethod(name = "inline?")
public IRubyObject
inline_eh(ThreadContext context)
{
return context.getRuntime().newBoolean(element.isInline());
}
@JRubyMethod(name = "empty?")
public IRubyObject
empty_eh(ThreadContext context)
{
return context.getRuntime().newBoolean(element.isEmpty());
}
@JRubyMethod()
public IRubyObject
sub_elements(ThreadContext context)
{
Ruby ruby = context.getRuntime();
List<String> subs = findSubElements(element);
IRubyObject[] ary = new IRubyObject[subs.size()];
for (int i = 0; i < subs.size(); ++i) {
ary[i] = ruby.newString(subs.get(i));
}
return ruby.newArray(ary);
}
}