001/**
002 *
003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either 
008 * version 2.1 of the License, or (at your option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013 * Lesser General Public License for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public 
016 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
017 * 
018 **/
019/**
020 * Implements the CFML Function mid
021 */
022package lucee.runtime.functions.string;
023
024import lucee.runtime.PageContext;
025import lucee.runtime.exp.ExpressionException;
026import lucee.runtime.exp.FunctionException;
027import lucee.runtime.exp.PageException;
028import lucee.runtime.functions.BIF;
029import lucee.runtime.op.Caster;
030
031public final class Mid extends BIF {
032        public static String call(PageContext pc , String str, double start) throws ExpressionException {
033                return call(pc,str,start,-1);
034        }
035        public static String call(PageContext pc , String str, double start, double count) throws ExpressionException {
036                int s=(int) (start-1);
037                int c=(int) count;
038                
039                if(s<0) throw new ExpressionException("Parameter 2 of function mid which is now ["+(s+1)+"] must be a positive integer");
040                if(c==-1) c=str.length();
041                else if(c<-1) throw new ExpressionException("Parameter 3 of function mid which is now ["+c+"] must be a non-negative integer or -1 (for string length)");
042                c+=s;
043                if(s>str.length()) return "";
044                else if(c>=str.length())return str.substring(s);
045                else {
046                        return str.substring(s,c);
047                }
048        }
049
050    @Override
051        public Object invoke(PageContext pc, Object[] args) throws PageException {
052        if(args.length==2)
053                        return call(pc, Caster.toString(args[0]), Caster.toDoubleValue(args[1]));
054        if(args.length==3)
055                        return call(pc, Caster.toString(args[0]), Caster.toDoubleValue(args[1]), Caster.toDoubleValue(args[2]));
056
057                throw new FunctionException(pc, "Mid", 2, 3, args.length);
058        }
059}