package info.bliki.wiki.template;
import info.bliki.wiki.filter.WikipediaScanner;
import info.bliki.wiki.model.IWikiModel;
import info.bliki.wiki.template.expr.eval.DoubleEvaluator;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* A template parser function for <code>{{ #ifexpr: ... }}</code> syntax
*
* See <a href="http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions">
* Mediwiki's Help:Extension:ParserFunctions</a> See: <a href="http://svn.wikimedia.org/viewvc/mediawiki/trunk/extensions/ParserFunctions/Expr.php?view=markup"
* >Expr.php in MediaWiki SVN</a>
*/
public class Ifexpr extends AbstractTemplateFunction {
public final static ITemplateFunction CONST = new Ifexpr();
public Ifexpr() {
}
public String parseFunction(char[] src, int beginIndex, int endIndex, IWikiModel model) throws IOException {
List<String> list = new ArrayList<String>();
WikipediaScanner.splitByPipe(src, beginIndex, endIndex, list);
if (list.size() > 1) {
String condition = parse(list.get(0), model);
if (condition.length() > 0) {
try {
DoubleEvaluator engine = new DoubleEvaluator();
double d = engine.evaluate(condition);
// if (d == 0.0) {
if (Math.abs(d - 0.0) < DoubleEvaluator.EPSILON) {
if (list.size() >= 3) {
// <else text>
return parse(list.get(2), model);
}
return null;
}
return parse(list.get(1), model);
} catch (Exception e) {
return "<div class=\"error\">Expression error: " + e.getMessage() + "</div>";
}
} else {
if (list.size() >= 3) {
// <else text>
return parse(list.get(2), model);
}
}
}
return null;
}
}