001/**
002The contents of this file are subject to the Mozilla Public License Version 1.1 
003(the "License"); you may not use this file except in compliance with the License. 
004You may obtain a copy of the License at http://www.mozilla.org/MPL/ 
005Software distributed under the License is distributed on an "AS IS" basis, 
006WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
007specific language governing rights and limitations under the License. 
008
009The Original Code is "TerserMessageRule.java".  Description: 
010"Validation rule for checking values extracted by a Terser" 
011
012The Initial Developer of the Original Code is University Health Network. Copyright (C) 
0132012.  All Rights Reserved. 
014
015Contributor(s): ______________________________________. 
016
017Alternatively, the contents of this file may be used under the terms of the 
018GNU General Public License (the "GPL"), in which case the provisions of the GPL are 
019applicable instead of those above.  If you wish to allow use of your version of this 
020file only under the terms of the GPL and not to allow others to use your version 
021of this file under the MPL, indicate your decision by deleting  the provisions above 
022and replace  them with the notice and other provisions required by the GPL License.  
023If you do not delete the provisions above, a recipient may use your version of 
024this file under either the MPL or the GPL. 
025 */
026package ca.uhn.hl7v2.validation.builder.support;
027
028import java.util.StringTokenizer;
029
030import ca.uhn.hl7v2.HL7Exception;
031import ca.uhn.hl7v2.Location;
032import ca.uhn.hl7v2.model.Message;
033import ca.uhn.hl7v2.model.Segment;
034import ca.uhn.hl7v2.util.Terser;
035import ca.uhn.hl7v2.validation.builder.Expression;
036import ca.uhn.hl7v2.validation.builder.Predicate;
037import ca.uhn.hl7v2.validation.builder.PredicateMessageRule;
038
039/**
040 * Validation rule for checking values extracted by a {@link Terser}.
041 * 
042 * @author Christian Ohr
043 */
044@SuppressWarnings("serial")
045public class TerserMessageRule extends PredicateMessageRule {
046
047    /**
048     * Creates a new instance of a terser message rule
049     * @param terserExpression terser string like "PID-3-1"
050     * @param predicate predicate used for the test
051     */
052        public TerserMessageRule(String terserExpression, Predicate predicate) {
053                super(predicate, new TerserExpression(terserExpression));
054        }
055
056        private static class TerserExpression implements Expression<Message> {
057
058                private String expression;
059
060                public TerserExpression(String expression) {
061                        super();
062                        this.expression = expression;
063                }
064
065                public Object evaluate(Message msg) throws HL7Exception {
066                        return new Terser(msg).get(expression);
067                }
068
069                public String getDescription() {
070                        // Terser Expression is equivalent with Location
071                        return "";
072                }
073
074                public Location getLocation(Message msg) throws HL7Exception {
075                        Terser t = new Terser(msg);
076                        StringTokenizer tok = new StringTokenizer(expression, "-", false);
077                        Segment segment = t.getSegment(tok.nextToken());
078                        Location location = new Location()
079                            .withSegmentName(segment.getName())
080                            .withFieldIndizes(Terser.getIndices(expression));
081                        return location;
082                }
083
084        }
085}