granicus.if.org Git - icinga2/blob - lib/base/value.h

   1 /******************************************************************************
   2  * Icinga 2                                                                   *
   3  * Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/)        *
   4  *                                                                            *
   5  * This program is free software; you can redistribute it and/or              *
   6  * modify it under the terms of the GNU General Public License                *
   7  * as published by the Free Software Foundation; either version 2             *
   8  * of the License, or (at your option) any later version.                     *
   9  *                                                                            *
  10  * This program is distributed in the hope that it will be useful,            *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
  13  * GNU General Public License for more details.                               *
  14  *                                                                            *
  15  * You should have received a copy of the GNU General Public License          *
  16  * along with this program; if not, write to the Free Software Foundation     *
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
  18  ******************************************************************************/
  19
  20 #ifndef VALUE_H
  21 #define VALUE_H
  22
  23 struct cJSON;
  24
  25 namespace icinga
  26 {
  27
  28 /**
  29  * A type that can hold an arbitrary value.
  30  *
  31  * @ingroup base
  32  */
  33 class I2_BASE_API Value
  34 {
  35 public:
  36         inline Value(void)
  37                 : m_Value()
  38         { }
  39
  40         inline Value(int value)
  41                 : m_Value(value)
  42         { }
  43
  44         inline Value(long value)
  45                 : m_Value(double(value))
  46         { }
  47
  48         inline Value(double value)
  49                 : m_Value(value)
  50         { }
  51
  52         inline Value(const String& value)
  53                 : m_Value(value)
  54         { }
  55
  56         inline Value(const char *value)
  57                 : m_Value(String(value))
  58         { }
  59
  60         template<typename T>
  61         inline Value(const shared_ptr<T>& value)
  62                 : m_Value()
  63         {
  64                 if (!value)
  65                         return;
  66
  67                 Object::Ptr object = dynamic_pointer_cast<Object>(value);
  68
  69                 if (!object)
  70                         throw_exception(invalid_argument("shared_ptr value type must inherit from Object class."));
  71
  72                 m_Value = object;
  73         }
  74
  75         operator double(void) const
  76         {
  77                 if (m_Value.type() != typeid(double)) {
  78                         return boost::lexical_cast<double>(m_Value);
  79                 } else {
  80                         return boost::get<double>(m_Value);
  81                 }
  82         }
  83
  84         operator String(void) const
  85         {
  86                 if (IsEmpty())
  87                         return String();
  88
  89                 if (m_Value.type() != typeid(String)) {
  90                         String result = boost::lexical_cast<String>(m_Value);
  91                         m_Value = result;
  92                 }
  93
  94                 return boost::get<String>(m_Value);
  95         }
  96
  97         template<typename T>
  98         operator shared_ptr<T>(void) const
  99         {
 100                 if (IsEmpty())
 101                         return shared_ptr<T>();
 102
 103                 shared_ptr<T> object = dynamic_pointer_cast<T>(boost::get<Object::Ptr>(m_Value));
 104
 105                 if (!object)
 106                         throw_exception(bad_cast());
 107
 108                 return object;
 109         }
 110
 111         bool IsEmpty(void) const;
 112         bool IsScalar(void) const;
 113         bool IsObject(void) const;
 114
 115         template<typename T>
 116         bool IsObjectType(void) const
 117         {
 118                 if (!IsObject())
 119                         return false;
 120
 121                 return (dynamic_pointer_cast<T>(boost::get<Object::Ptr>(m_Value)));
 122         }
 123
 124         static Value FromJson(cJSON *json);
 125         cJSON *ToJson(void) const;
 126
 127         String Serialize(void) const;
 128         static Value Deserialize(const String& jsonString);
 129
 130 private:
 131         mutable boost::variant<boost::blank, double, String, Object::Ptr> m_Value;
 132 };
 133
 134 static Value Empty;
 135
 136 }
 137
 138 #endif /* VALUE_H */