01: /*
02: * $Id: LTrimFunction.java,v 1.7 2005/05/02 22:28:41 ahimanikya Exp $
03: * =======================================================================
04: * Copyright (c) 2002 Axion Development Team. All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: *
10: * 1. Redistributions of source code must retain the above
11: * copyright notice, this list of conditions and the following
12: * disclaimer.
13: *
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in
16: * the documentation and/or other materials provided with the
17: * distribution.
18: *
19: * 3. The names "Tigris", "Axion", nor the names of its contributors may
20: * not be used to endorse or promote products derived from this
21: * software without specific prior written permission.
22: *
23: * 4. Products derived from this software may not be called "Axion", nor
24: * may "Tigris" or "Axion" appear in their names without specific prior
25: * written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
30: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38: * =======================================================================
39: */
40: package org.axiondb.functions;
41:
42: import org.axiondb.AxionException;
43: import org.axiondb.DataType;
44: import org.axiondb.FunctionFactory;
45: import org.axiondb.RowDecorator;
46: import org.axiondb.types.StringType;
47:
48: /**
49: * @version $Revision: 1.7 $ $Date: 2005/05/02 22:28:41 $
50: * @author Sudhendra Seshachala
51: * @author Ahimanikya Satapathy
52: */
53: public class LTrimFunction extends BaseFunction implements
54: ScalarFunction, FunctionFactory {
55:
56: /** Creates a new instance of Class */
57: public LTrimFunction() {
58: super ("LTRIM");
59: }
60:
61: public ConcreteFunction makeNewInstance() {
62: return new LTrimFunction();
63: }
64:
65: /** {@link StringType} */
66: public DataType getDataType() {
67: return RETURN_TYPE;
68: }
69:
70: public Object evaluate(RowDecorator row) throws AxionException {
71: char trimChar = ' '; // default trim char
72: if (getArgumentCount() == 2) {
73: Object trimCharObj = getArgument(1).evaluate(row);
74: String trimCharStr = (String) RETURN_TYPE
75: .convert(trimCharObj);
76: if (trimCharStr != null && trimCharStr.length() > 0) {
77: trimChar = trimCharStr.charAt(0);
78: }
79: }
80:
81: Object trimSourceObj = getArgument(0).evaluate(row);
82: String trimSourceStr = (String) RETURN_TYPE
83: .convert(trimSourceObj);
84: int trimSourceLen = trimSourceStr.length();
85: int i = 0;
86: for (; i < trimSourceLen && trimSourceStr.charAt(i) == trimChar; i++)
87: ;
88: trimSourceStr = ((i == 0) ? trimSourceStr : trimSourceStr
89: .substring(i));
90:
91: return trimSourceStr;
92: }
93:
94: public boolean isValid() {
95: return (getArgumentCount() >= 1 && getArgumentCount() < 3);
96: }
97:
98: private static final DataType RETURN_TYPE = new StringType();
99: }
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