aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package com.sun.xml.internal.xsom;
aoqi@0: 
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.Iterators;
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.ParseException;
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.SCDImpl;
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.SCDParser;
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.Step;
aoqi@0: import com.sun.xml.internal.xsom.impl.scd.TokenMgrError;
aoqi@0: import com.sun.xml.internal.xsom.util.DeferedCollection;
aoqi@0: 
aoqi@0: import javax.xml.namespace.NamespaceContext;
aoqi@0: import java.util.Collection;
aoqi@0: import java.util.Iterator;
aoqi@0: import java.util.List;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * Schema Component Designator (SCD).
aoqi@0:  *
aoqi@0:  * <p>
aoqi@0:  * SCD for schema is what XPath is for XML. SCD allows you to select a schema component(s)
aoqi@0:  * from a schema component(s).
aoqi@0:  *
aoqi@0:  * <p>
aoqi@0:  * See <a href="http://www.w3.org/TR/2005/WD-xmlschema-ref-20050329/">XML Schema: Component Designators</a>.
aoqi@0:  * This implementation is based on 03/29/2005 working draft.
aoqi@0:  *
aoqi@0:  * @author Kohsuke Kawaguchi
aoqi@0:  */
aoqi@0: public abstract class SCD {
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Parses the string representation of SCD.
aoqi@0:      *
aoqi@0:      * <p>
aoqi@0:      * This method involves parsing the path expression and preparing the in-memory
aoqi@0:      * structure, so this is useful when you plan to use the same SCD against
aoqi@0:      * different context node multiple times.
aoqi@0:      *
aoqi@0:      * <p>
aoqi@0:      * If you want to evaluate SCD just once, use {@link XSComponent#select} methods.
aoqi@0:      *
aoqi@0:      * @param path
aoqi@0:      *      the string representation of SCD, such as "/foo/bar".
aoqi@0:      * @param nsContext
aoqi@0:      *      Its {@link NamespaceContext#getNamespaceURI(String)} is used
aoqi@0:      *      to resolve prefixes in the SCD to the namespace URI.
aoqi@0:      */
aoqi@0:     public static SCD create(String path, NamespaceContext nsContext) throws java.text.ParseException {
aoqi@0:         try {
aoqi@0:             SCDParser p = new SCDParser(path,nsContext);
aoqi@0:             List<?> list = p.RelativeSchemaComponentPath();
aoqi@0:             return new SCDImpl(path,list.toArray(new Step[list.size()]));
aoqi@0:         } catch (TokenMgrError e) {
aoqi@0:             throw setCause(new java.text.ParseException(e.getMessage(), -1 ),e);
aoqi@0:         } catch (ParseException e) {
aoqi@0:             throw setCause(new java.text.ParseException(e.getMessage(), e.currentToken.beginColumn ),e);
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     private static java.text.ParseException setCause(java.text.ParseException e, Throwable x) {
aoqi@0:         e.initCause(x);
aoqi@0:         return e;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the given context node and
aoqi@0:      * returns the matched nodes.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      could be empty but never be null.
aoqi@0:      */
aoqi@0:     public final Collection<XSComponent> select(XSComponent contextNode) {
aoqi@0:         return new DeferedCollection<XSComponent>(select(Iterators.singleton(contextNode)));
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the whole schema and
aoqi@0:      * returns the matched nodes.
aoqi@0:      *
aoqi@0:      * <p>
aoqi@0:      * This method is here because {@link XSSchemaSet}
aoqi@0:      * doesn't implement {@link XSComponent}.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      could be empty but never be null.
aoqi@0:      */
aoqi@0:     public final Collection<XSComponent> select(XSSchemaSet contextNode) {
aoqi@0:         return select(contextNode.getSchemas());
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the given context node and
aoqi@0:      * returns the matched node.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      null if the SCD didn't match anything. If the SCD matched more than one node,
aoqi@0:      *      the first one will be returned.
aoqi@0:      */
aoqi@0:     public final XSComponent selectSingle(XSComponent contextNode) {
aoqi@0:         Iterator<XSComponent> r = select(Iterators.singleton(contextNode));
aoqi@0:         if(r.hasNext())     return r.next();
aoqi@0:         return null;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the whole schema set and
aoqi@0:      * returns the matched node.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      null if the SCD didn't match anything. If the SCD matched more than one node,
aoqi@0:      *      the first one will be returned.
aoqi@0:      */
aoqi@0:     public final XSComponent selectSingle(XSSchemaSet contextNode) {
aoqi@0:         Iterator<XSComponent> r = select(contextNode.iterateSchema());
aoqi@0:         if(r.hasNext())     return r.next();
aoqi@0:         return null;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the given set of context nodes and
aoqi@0:      * returns the matched nodes.
aoqi@0:      *
aoqi@0:      * @param contextNodes
aoqi@0:      *      {@link XSComponent}s that represent the context node against
aoqi@0:      *      which {@link SCD} is evaluated.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      could be empty but never be null.
aoqi@0:      */
aoqi@0:     public abstract Iterator<XSComponent> select(Iterator<? extends XSComponent> contextNodes);
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Evaluates the SCD against the given set of context nodes and
aoqi@0:      * returns the matched nodes.
aoqi@0:      *
aoqi@0:      * @param contextNodes
aoqi@0:      *      {@link XSComponent}s that represent the context node against
aoqi@0:      *      which {@link SCD} is evaluated.
aoqi@0:      *
aoqi@0:      * @return
aoqi@0:      *      could be empty but never be null.
aoqi@0:      */
aoqi@0:     public final Collection<XSComponent> select(Collection<? extends XSComponent> contextNodes) {
aoqi@0:         return new DeferedCollection<XSComponent>(select(contextNodes.iterator()));
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns the textual SCD representation as given to {@link SCD#create(String, NamespaceContext)}.
aoqi@0:      */
aoqi@0:     public abstract String toString();
aoqi@0: }