Subversion Repositories mkgmap

/*
 * Copyright (c) 2015.
 *
 * This program is free software; you can redistribute it and/or modify it under the terms
 * of the GNU General Public License version 3 or version 2 as published by the Free
 * Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU General Public License for more details.
 */
package uk.me.parabola.mkgmap.osmstyle.actions;

import java.util.regex.Pattern;

import uk.me.parabola.mkgmap.reader.osm.Element;
import uk.me.parabola.mkgmap.reader.osm.TagDict;
import uk.me.parabola.mkgmap.scan.SyntaxException;

/**
 * This can be used to filter out redundant values.<br>
 * <br>
 * The filter checks whether the value is contained within another tag's value.
 * If so, a null string is returned.<br>
 * <br>
 * Another tag should consist of values separated by a delimiter (semicolon ';'
 * by default).<br>
 * <br>
 * Example:<br>
 * <code>
 * type=route & route=bus & ref=* {<br>
 *              apply {<br>
 *                      set route_ref='$(route_ref),${ref|not-contained:,:route_ref}' | '$(route_ref)' | '${ref}';<br>
 *              }<br>
 * }</code><br>
 * Here, ref value is only added to route_ref when it is not already contained
 * in that list (with separator ','). Otherwise, the value of route_ref is
 * unchanged.
 *
 * @author Maxim Duester
 */
public class NotContainedFilter extends ValueFilter {
        private String separator;
        private short tagKey;

        public NotContainedFilter(String arg) {
                String[] temp = arg.split(":");

                if (temp.length < 2 || temp[1].isEmpty())
                        throw new SyntaxException(
                                        "Missing tag to compare in style not-contained command: "
                                                        + arg);

                // set the separator (default to ;)
                if (temp[0].length() > 0)
                        separator = temp[0];
                else
                        separator = ";";
                // set the tag short value
                tagKey = TagDict.getInstance().xlate(temp[1]);
        }

        public String doFilter(String value, Element el) {
                if (value == null)
                        return null;

                String tagValue = el.getTag(tagKey);
                // tag not found => value not in tag's value
                if (tagValue == null)
                        return value;

                // split uses a regex we need to replace special characters
                String[] temp = tagValue.split(Pattern.quote(separator));

                for (String s : temp)
                        if (s.equals(value))
                                return null;

                // nothing found => value not in tag's value
                return value;
        }
}