01: // Copyright 2006 The Apache Software Foundation
02: //
03: // Licensed under the Apache License, Version 2.0 (the "License");
04: // you may not use this file except in compliance with the License.
05: // You may obtain a copy of the License at
06: //
07: // http://www.apache.org/licenses/LICENSE-2.0
08: //
09: // Unless required by applicable law or agreed to in writing, software
10: // distributed under the License is distributed on an "AS IS" BASIS,
11: // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12: // See the License for the specific language governing permissions and
13: // limitations under the License.
14:
15: package org.apache.tapestry.services;
16:
17: /**
18: * Encapsulates persisted property information for an entire page.
19: */
20: public interface PersistentFieldBundle {
21: /**
22: * Checks to see if a persistent value has been stored for the indicated component and field.
23: * TODO: This method can probably be removed; it doesn't look like its used (instead, we if
24: * check getValue() returns null).
25: *
26: * @param componentId
27: * the nested id of the component (within the page), may be null or blank for the
28: * root component of the page
29: * @param fieldName
30: * the name of the field whose value was persisted
31: * @return true if a change has been stored
32: */
33: boolean containsValue(String componentId, String fieldName);
34:
35: /**
36: * @param componentId
37: * the nested if of the component (within the page), may be null or blank for the
38: * root component of the page
39: * @param fieldName
40: * the name of the field whose value was persisted
41: * @return the persisted value, possibly null
42: */
43: Object getValue(String componentId, String fieldName);
44: }
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