1 /*
2  * Copyright (c) 2011-2015, 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:
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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
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24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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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 #include <memory>
38 #include <utility>
39 
40 /** Factory that creates an element given an xml element. If no matching builder is found, it uses
41   * the default builder.
42   *
43   * @tparam CDefaultElementBuilder is the class of the element builder to use if no corresponding
44   *                                builder is found for a given xml element.
45   */
46 template <class CDefaultElementBuilder>
47 class CDefaultElementLibrary : public CElementLibrary
48 {
49 public:
50     virtual ~CDefaultElementLibrary() = default;
51 
52     /** Set the default builder used in fallback mechanism.
53       * @see createElement() for more detail on this mechanism.
54       *
55       * @param[in] defaultBuilder if NULL default builder mechanism, else provided builder is used.
56       */
setDefaultBuilder(std::unique_ptr<CDefaultElementBuilder> defaultBuilder)57     void setDefaultBuilder(std::unique_ptr<CDefaultElementBuilder> defaultBuilder)
58     {
59         _defaultBuilder = std::move(defaultBuilder);
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     std::unique_ptr<CDefaultElementBuilder> _defaultBuilder;
76 };
77 
78 template <class CDefaultElementBuilder>
createElement(const CXmlElement & xmlElement)79 CElement *CDefaultElementLibrary<CDefaultElementBuilder>::createElement(
80     const CXmlElement &xmlElement) const
81 {
82     CElement *builtElement = CElementLibrary::createElement(xmlElement);
83 
84     if (builtElement != NULL) {
85         // The element was created, return it
86         return builtElement;
87     }
88 
89     if (_defaultBuilder == nullptr) {
90         // The default builder mechanism is not enabled
91         return NULL;
92     }
93 
94     // Use the default builder
95     return _defaultBuilder->createElement(xmlElement);
96 }
97