1 /*
2 * Copyright 2008 FatWire Corporation. All Rights Reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.fatwire.gst.foundation.facade.runtag.vdm;
18
19 import COM.FutureTense.Interfaces.ICS;
20
21 import com.fatwire.gst.foundation.facade.runtag.TagRunner;
22
23 /**
24 * Sets an alias ONLY if it has not been set before. Avoids unnecessary DB
25 * thrash.
26 *
27 * @author Tony Field
28 * @since Sep 29, 2008
29 */
30 public class SetAliasWithoutReset implements TagRunner {
31
32 private final String key;
33
34 private final String value;
35
36 public SetAliasWithoutReset(final String key, final String value) {
37 super();
38 this.key = key;
39 this.value = value;
40 }
41
42 public String execute(final ICS ics) {
43 final String varname = "alias" + ics.genID(true);
44 try {
45 GetAlias getAlias = new GetAlias(key, varname);
46 String getResult = getAlias.execute(ics);
47 String alias = ics.GetVar(varname);
48 if (alias != null && alias.equals(value) || alias == null && value == null) {
49 // nothing to do. this saves a lot of processing
50 return getResult;
51 }
52
53 SetAlias setAlias = new SetAlias(key, value);
54 return setAlias.execute(ics);
55
56 } finally {
57 // cleaning up
58 ics.RemoveVar(varname);
59 }
60 }
61
62 public String getValue() {
63 return value;
64 }
65
66 public String getKey() {
67 return key;
68 }
69
70 }