/*
* 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 com.hp.hpl.jena.sparql.sse.lang;
import java.util.Iterator ;
import java.util.Stack ;
import org.openjena.atlas.lib.StrUtils ;
import com.hp.hpl.jena.shared.PrefixMapping ;
import com.hp.hpl.jena.sparql.core.Prologue ;
import com.hp.hpl.jena.sparql.sse.Item ;
import com.hp.hpl.jena.sparql.sse.ItemList ;
import com.hp.hpl.jena.sparql.sse.builders.BuilderPrefixMapping ;
/** Resolve syntacic forms like (base ...) and (prefix...)
* where the syntax modifies the enclosed sub term.
*
*
* Forms:
* (FORM DECL... TERM) => where TERM is the result.
* Examples
* (prefix (PREFIXES) TERM) => TERM with prefix names expanded
* (base IRI TERM) => TERM with IRIs resolved to absolute IRIs
*
* The DECL part can not itself have nested, independent forms
* unless a subclass (carefully) manages that. */
public class ParseHandlerResolver extends ParseHandlerForm
{
private static final String prefixTag = "prefix" ;
private static final String baseTag = "base" ;
private PrefixMapping topMap = null ;
private String topBase = null ;
private Prologue prologue = null ;
private ItemList declList = null ;
private Stack<Prologue> state = new Stack<Prologue>() ; // Previous prologues (not the current one)
public ParseHandlerResolver(Prologue p)
{
prologue = p ;
}
@Override
protected void declItem(ItemList list, Item item)
{
if ( list != declList )
// Deeper
return ;
// Prefix - deeper than one.
boolean isBase = list.get(0).isSymbol(baseTag) ;
boolean isPrefix = list.get(0).isSymbol(prefixTag) ;
// Old state has already been saved.
if ( isBase )
{
if ( ! item.isNode() )
throwException("(base ...): not an RDF node for the base.", item) ;
if ( ! item.getNode().isURI() )
throwException("(base ...): not an IRI for the base.", item) ;
String baseIRI = item.getNode().getURI() ;
prologue = prologue.sub(baseIRI) ;
// Remeber first base seen
if ( topBase == null )
topBase = baseIRI ;
return ;
}
if ( isPrefix )
{
PrefixMapping newMappings = BuilderPrefixMapping.build(item) ;
prologue = prologue.sub(newMappings) ;
// Remember first prefix mapping seen.
if( topMap == null )
topMap = newMappings ;
return ;
}
throwException("Inconsistent: "+list.shortString(), list) ;
}
@Override
protected boolean endOfDecl(ItemList list, Item item)
{
// Both (base...) and (prefix...) have one decl item
if ( declList == list && list.size() == 2 )
{
declList = null ;
return true ;
}
return false ;
}
@Override
protected boolean isForm(Item tag)
{
return tag.isSymbol(baseTag) || tag.isSymbol(prefixTag) ;
}
@Override
protected void startForm(ItemList list)
{
// Remember the top of declaration
declList = list ;
state.push(prologue) ;
}
private void dump()
{
Iterator<Prologue> iter = state.iterator() ;
for ( ; iter.hasNext() ; )
{
Prologue p = iter.next() ;
System.out.println(" Prologue: "+p.getBaseURI()) ;
}
}
@Override
protected void finishForm(ItemList list)
{
// Check list length
prologue = state.pop() ;
// Restore state
// Choose the result.
if ( list.size() > 2 )
{
Item item = list.getLast() ;
super.setFormResult(item) ;
}
}
@Override
public void emitIRI(int line, int column, String iriStr)
{
iriStr = resolveIRI(iriStr, line, column) ;
super.emitIRI(line, column, iriStr) ;
}
@Override
public void emitPName(int line, int column, String pname)
{
if ( inFormDecl() )
{
// Record a faked PName. Works with BuilderPrefixMapping
Item item = Item.createSymbol(pname, line, column) ;
listAdd(item) ;
return ;
}
String iriStr = resolvePrefixedName(pname, line, column) ;
super.emitIRI(line, column, iriStr) ;
}
@Override
protected String resolvePrefixedName(String pname, int line, int column)
{
if ( prologue.getPrefixMapping() == null )
throwException("No prefix mapping for prefixed name: "+pname, line, column) ;
if ( ! StrUtils.contains(pname, ":") )
throwException("Prefixed name does not have a ':': "+pname, line, column) ;
String uri = prologue.getPrefixMapping().expandPrefix(pname) ;
if ( uri == null || uri.equals(pname) )
throwException("Can't resolve prefixed name: "+pname, line, column) ;
return uri ;
}
private String resolveIRI(String iriStr, int line, int column)
{
if ( prologue.getResolver() != null )
return prologue.getResolver().resolve(iriStr) ;
return iriStr ;
}
}