1 /*
2  * Copyright (c) 2011-2014, Intel Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without modification,
6  * are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice, this
9  * list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation and/or
13  * other materials provided with the distribution.
14  *
15  * 3. Neither the name of the copyright holder nor the names of its contributors
16  * may be used to endorse or promote products derived from this software without
17  * specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
26  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 #pragma once
31 
32 #include "ElementLibrary.h"
33 #include "ElementBuilder.h"
34 
35 #include <map>
36 #include <string>
37 
38 /** Factory that creates an element given an xml element. If no matching builder is found, it uses
39   * the default builder.
40   *
41   * @tparam CDefaultElementBuilder is the class of the element builder to use if no corresponding
42   *                                builder is found for a given xml element.
43   */
44 template<class CDefaultElementBuilder>
45 class CDefaultElementLibrary: public CElementLibrary
46 {
47 public:
48 
49     explicit CDefaultElementLibrary(bool bEnableDefaultMechanism = true);
~CDefaultElementLibrary()50     virtual ~CDefaultElementLibrary() {}
51 
52     /** Enable the default builder fallback mechanism.
53       * @see createElement() for more detail on this mechanism.
54       *
55       * @param[in] bEnable if true/false, activate/deactivate the default builder mechanism.
56       */
enableDefaultMechanism(bool bEnable)57     void enableDefaultMechanism(bool bEnable) {
58         _bEnableDefaultMechanism = bEnable;
59     }
60 
61 
62     /** Create and return an element instanciated depending on an xmlElement.
63       *
64       * @param[in] xmlElement: The xml element used to find a matching builder
65       *
66       * @return If a matching builder is found, return an element created from the builder,
67       *         otherwise:
68       *             If the default mechanism is enable (@see enableDefaultMechanism),
69       *                 create the elemen with the default element builder.
70       *             otherwise, return NULL.
71       */
72     CElement* createElement(const CXmlElement& xmlElement) const;
73 
74 private:
75     bool _bEnableDefaultMechanism;
76     CDefaultElementBuilder _DefaultElementBuilder;
77 };
78 
79 template<class CDefaultElementBuilder>
CDefaultElementLibrary(bool bEnableDefaultMechanism)80 CDefaultElementLibrary<CDefaultElementBuilder>::CDefaultElementLibrary(bool bEnableDefaultMechanism) :
81         _bEnableDefaultMechanism(bEnableDefaultMechanism),
82         _DefaultElementBuilder() {}
83 
84 template<class CDefaultElementBuilder>
createElement(const CXmlElement & xmlElement)85 CElement* CDefaultElementLibrary<CDefaultElementBuilder>::createElement(const CXmlElement& xmlElement) const
86 {
87     CElement* builtElement = CElementLibrary::createElement(xmlElement);
88 
89     if (builtElement != NULL) {
90         // The element was created, return it
91         return builtElement;
92     }
93 
94     if (!_bEnableDefaultMechanism) {
95         // The default builder mechanism is not enabled
96         return NULL;
97     }
98 
99     // Use the default builder
100     return _DefaultElementBuilder.createElement(xmlElement);
101 }
102 
103