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   1 /**
   2  * @file Common/inifile.h
   3  * @brief Class for reading and writing parameter values in INI files.
   4  * @author Enar Vaikene
   5  *
   6  * Copyright (c) 2011 Enar Vaikene
   7  *
   8  * This file is part of the eVaf C++ cross-platform application development framework.
   9  *
  10  * This file can be used under the terms of the GNU General Public License
  11  * version 3.0 as published by the Free Software Foundation and appearing in
  12  * the file LICENSE included in the packaging of this file. Please review the
  13  * the following information to ensure the GNU General Public License version
  14  * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
  15  *
  16  * Alternatively, this file may be used in accordance with the Commercial License
  17  * Agreement provided with the Software.
  18  */
  19
  20 #ifndef __COMMON_INIFILE_H
  21 #define   __COMMON_INIFILE_H
  22
  23 #include "libcommon.h"
  24
  25 namespace eVaf {
  26 namespace Common {
  27 namespace Internal {
  28     class IniFileImpl;
  29 } // namespace eVaf::Common::Internal
  30
  31 /**
  32  * Class for reading and writing parameter values in INI files.
  33  *
  34  * The IniFile class provides access to parameter values in a standard INI file. Every parameter value is
  35  * identified by a section/key name pair. Key names can be prefixed with 'windows:' or 'linux:' if the
  36  * parameter value is specific for the given platform. This allows entering platform-specific parameter
  37  * values to the INI file. INI files can contain comment lines that start with ';' or '#'. Comments are
  38  * preserved when new values are written to the INI file.
  39  *
  40  * Values in INI files are stored as strings and the IniFile class expects them to use specific formats if
  41  * the returned value is supposed to be of a different data type. The following list shows the expected format
  42  * of different data types:
  43  *
  44  * @li Bool - '0', 'false', 'off', 'no' are equal to false and '1', 'true', 'on', 'yes' are equal to true;
  45  * @li Char - a single character or an ASCII code as '\0NNN' or '\0xNN';
  46  * @li Date - date string in the ISO 8601 format YYYY-MM-DD;
  47  * @li DateTime - date and time string in the ISO 8601 format YYY-MM-DDTHH:MM:SSTZD;
  48  * @li Double - the decimal point is always '.' regardless of the locale;
  49  * @li Int - only base 10 (decimal) is allowed;
  50  * @li Time - 24h time string in the format HH:MM:SS
  51  * @li UInt - base 16 (hex) if the string is prefixed with '0x'; base 8 if the string starts with '0'; otherwise
  52  * the value is expected to be base 10 (decimal).
  53  */
  54 class COMMON_EXPORT IniFile
  55 {
  56 public:
  57
  58     /**
  59      * Creates the INI file object
  60      * @param fileName Name of the INI file
  61      * @param mode File opening mode
  62      */
  63     IniFile(QString const & fileName, QIODevice::OpenMode mode = QIODevice::ReadWrite);
  64
  65     /// Dtor
  66     ~IniFile();
  67
  68     /**
  69      * Returns true if the object is valid
  70      *
  71      * The isValid() method returns true if the INI file is can be used. Use this
  72      * method after creating the object to verify that opening the INI file in the specified
  73      * mode succeeded.
  74      *
  75      * If the object is not valid, then:
  76      * @li Writing to the INI file always fails; the internal cache is still updated and reading the parameter returns
  77      * the new value;
  78      * @li Reading from the INI file returns the cached value or the default value if no values with this name are written.
  79      */
  80     bool isValid() const;
  81
  82     /**
  83      * Returns the last error message.
  84      *
  85      * The errorString() method returns a human-readable error message if an operation with the INI file failed.
  86      */
  87     QString errorString() const;
  88
  89     /**
  90      * Reads a value from the INI file.
  91      * @param paramName Name of the parameter
  92      * @param defaultValue Default value returned if the parameter value cannot be read
  93      * @return The value from the INI file or an invalid QVariant if failed
  94      *
  95      * The getValue() method reads a parameter value from the INI file. Parameters are identified by a section and key name pair
  96      * in the format '&lt;section&gt;/&lt;key&gt'. For example, if the section is called 'general' and the key is called 'log_level',
  97      * then the name of the parameter should be given as 'general/log_level'. Parameter names are case insensitive.
  98      *
  99      * If the parameter cannot be read because it is not found in the INI file or the INI file object is invalid, returns the
 100      * default value. If reading the parameter fails by any other reasons, returns an invalid QVariant value (QVariant::Invalid).
 101      *
 102      * If the default value is of a valid and known QVariant type, then its type is used to validate and optionally convert
 103      * the string read from the INI file. For example:
 104      * @li If the value in the INI file is 'abc' and the default value an integer value, then validation
 105      * fails and the method returns the default value;
 106      * @li If the default value is a boolean value, then the method accepts '1', 'true', 'on' and 'yes' as valid values.
 107      */
 108     QVariant getValue(QString const & paramName, QVariant const & defaultValue = QVariant::Invalid);
 109
 110     /**
 111      * Writes a value to the INI file.
 112      * @param paramName Name of the parameter
 113      * @param value The value of the value
 114      * @return True if succeeded and false if not
 115      *
 116      * The setValue() method writes a parameter value to the INI file. Parameters are identified by a section and key name pair
 117      * in the format '&lt;section&gt;/&lt;key&gt;'. For example, if the section is called 'general' and the key is called 'log_level',
 118      * the the name of the parameter should be given as 'general/log_level'. Parameter names are case insensitive.
 119      *
 120      * The method returns true if the parameter value was written into the INI file and false if not. Use the errorString() method
 121      * to get a human-readable error string if writing to the INI file fails.
 122      *
 123      * Writing to an invalid INI file always fails, but the value is still stored into the internal cache. Readin the same parameter
 124      * value returns the new value even if it was actually not stored into the INI file.
 125      */
 126     bool setValue(QString const & paramName, QVariant const & value);
 127
 128
 129 private:
 130
 131     /// Pointer to the internal implementation of the class
 132     Internal::IniFileImpl * d;
 133
 134 };
 135
 136 } // namespace eVaf::Common
 137 } // namespace eVaf
 138
 139 #endif // INIFILE_H