sascha@959: package de.intevation.flys.artifacts.services.meta;
sascha@959: 
sascha@959: import java.util.List;
sascha@974: import java.util.Collection;
sascha@974: import java.util.Map;
sascha@959: import java.util.ArrayList;
sascha@959: 
sascha@959: import javax.xml.xpath.XPathFunctionResolver;
sascha@959: import javax.xml.xpath.XPathFunction;
sascha@959: import javax.xml.xpath.XPathFunctionException;
sascha@959: 
sascha@959: import javax.xml.namespace.QName;
sascha@959: 
sascha@976: import org.apache.log4j.Logger;
sascha@976: 
sascha@959: public class FunctionResolver
sascha@959: implements   XPathFunctionResolver
sascha@959: {
sascha@976:     private static Logger log = Logger.getLogger(FunctionResolver.class);
sascha@976: 
sascha@959:     public static final String FUNCTION_NAMESPACE_URI = "dc";
sascha@959: 
sascha@959:     public static final class Entry {
sascha@959: 
sascha@959:         String        name;
sascha@959:         XPathFunction function;
sascha@959:         int           arity;
sascha@959: 
sascha@959:         public Entry() {
sascha@959:         }
sascha@959: 
sascha@959:         public Entry(String name, XPathFunction function, int arity) {
sascha@959:             this.name     = name;
sascha@959:             this.function = function;
sascha@959:             this.arity    = arity;
sascha@959:         }
sascha@959:     } // class Entry
sascha@959: 
sascha@959:     public static final FunctionResolver FUNCTIONS = new FunctionResolver();
sascha@959: 
sascha@959:     static {
sascha@959:         FUNCTIONS.addFunction("contains", 2, new XPathFunction() {
sascha@959:             @Override
sascha@959:             public Object evaluate(List args) throws XPathFunctionException {
sascha@974:                 Object haystack = args.get(0);
sascha@974:                 Object needle   = args.get(1);
sascha@959:                 try {
sascha@974:                     if (haystack instanceof Collection) {
sascha@974:                         return Boolean.valueOf(
sascha@974:                             ((Collection)haystack).contains(needle));
sascha@974:                     }
sascha@974: 
sascha@974:                     if (haystack instanceof Map) {
sascha@974:                         return Boolean.valueOf(
sascha@974:                             ((Map)haystack).containsKey(needle));
sascha@974:                     }
sascha@974: 
sascha@974:                     if (haystack instanceof Object []) {
sascha@974:                         for (Object straw: (Object [])haystack) {
sascha@974:                             if (straw.equals(needle)) {
sascha@974:                                 return Boolean.TRUE;
sascha@974:                             }
sascha@959:                         }
sascha@959:                     }
sascha@974: 
sascha@959:                     return Boolean.FALSE;
sascha@959:                 }
sascha@959:                 catch (Exception e) {
sascha@976:                     log.error(e);
sascha@959:                     throw new XPathFunctionException(e);
sascha@959:                 }
sascha@959:             }
sascha@959:         });
sascha@959:     }
sascha@959: 
sascha@959:     protected List<Entry> functions;
sascha@959: 
sascha@959:     public FunctionResolver() {
sascha@959:         functions = new ArrayList<Entry>();
sascha@959:     }
sascha@959: 
sascha@959:     public void addFunction(String name, int arity, XPathFunction function) {
sascha@959:         functions.add(new Entry(name, function, arity));
sascha@959:     }
sascha@959: 
sascha@959:     @Override
sascha@959:     public XPathFunction resolveFunction(QName functionName, int arity) {
sascha@959: 
sascha@959:         if (!functionName.getNamespaceURI().equals(FUNCTION_NAMESPACE_URI)) {
sascha@959:             return null;
sascha@959:         }
sascha@959: 
sascha@959:         String name = functionName.getLocalPart();
sascha@959:         for (Entry entry: functions) {
sascha@959:             if (entry.arity == arity && entry.name.equals(name)) {
sascha@959:                 return entry.function;
sascha@959:             }
sascha@959:         }
sascha@959: 
sascha@959:         return null;
sascha@959:     }
sascha@959: }
sascha@959: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :