/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.arq.querybuilder.handlers;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;
import org.apache.jena.graph.Node ;
import org.apache.jena.query.Query ;
import org.apache.jena.riot.system.IRIResolver;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.shared.impl.PrefixMappingImpl;
import org.apache.jena.sparql.core.Var ;
/**
* The proglog handler
*
*/
public class PrologHandler implements Handler {
// the query to modify.
private final Query query;
/**
* Constructor.
* @param query The query to handle.
*/
public PrologHandler(Query query) {
this.query = query;
}
/**
* get the canonical prefix name.
*
* Removes ':' from the end of the name if present.
*
* @param x The prefix name
* @return The prefix name with the trialing ':' removed.
*/
private String canonicalPfx(String x) {
if (x.endsWith(":"))
return x.substring(0, x.length() - 1);
return x;
}
/**
* Set the base for the query. This is the IRI against which relative names will be resolved.
* @param resolver The IRIResolver to set the base from.
*/
public void setBase(IRIResolver resolver) {
query.setBaseURI(resolver);
}
/**
* Set the base for the query. This is the IRI against which relative names will be resolved.
* @param base The string to set the base from.
*/
public void setBase(String base) {
query.setBaseURI(base);
}
/**
* Add a prefix to the prefix mapping.
* @param pfx The prefix to add.
* @param uri The uri to resolve the prefix to.
*/
public void addPrefix(String pfx, String uri) {
query.setPrefix(canonicalPfx(pfx), uri);
}
/**
* Clear the prefix mapping.
*/
public void clearPrefixes() {
query.setPrefixMapping( new PrefixMappingImpl() );
}
/**
* Add the map of prefixes to the query prefixes.
* @param prefixes The map of prefixs to URIs.
*/
public void addPrefixes(Map<String, String> prefixes) {
for (Map.Entry<String, String> e : prefixes.entrySet()) {
addPrefix(e.getKey(), e.getValue());
}
}
public PrefixMapping getPrefixes() {
return query.getPrefixMapping();
}
/**
* Add prefixes from a prefix mapping.
* @param prefixes THe prefix mapping to add from.
*/
public void addPrefixes(PrefixMapping prefixes) {
query.getPrefixMapping().setNsPrefixes(prefixes);
}
/**
* Add the settings from the prolog handler argument.
* @param pfxHandler The PrologHandler to read from
*/
public void addAll(PrologHandler pfxHandler) {
String val = StringUtils.defaultIfEmpty(pfxHandler.query.getBaseURI(),
query.getBaseURI());
if (val != null) {
setBase(val);
}
addPrefixes(pfxHandler.query.getPrefixMapping());
}
@Override
public void setVars(Map<Var, Node> values) {
// nothing to do
}
@Override
public void build() {
// no special operation to perform
}
}