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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) 2011-2019 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 #include <QString>
  26 #include <QVariant>
  27 #include <QIODevice>
  28 #include <QScopedPointer>
  29
  30 namespace eVaf {
  31 namespace Common {
  32 namespace Internal {
  33     class IniFileImpl;
  34 } // namespace eVaf::Common::Internal
  35
  36 /**
  37  * Class for reading and writing parameter values in INI files.
  38  *
  39  * The IniFile class provides access to parameter values in a standard INI file.
  40  * Every parameter value is identified by a section/key name pair. Key names can be prefixed with
  41  * 'windows:' or 'linux:' if the parameter value is specific for the given platform.
  42  * This allows entering platform-specific parameter values to the INI file.
  43  *
  44  * INI files can contain comment lines that start with ';' or '#'. Comments are
  45  * preserved when new values are written to the INI file.
  46  *
  47  * This is a sample INI %file:
  48  * @code
  49  * [main]
  50  * # The full name of this parameter is 'main/name'
  51  * name = "My Application"
  52  *
  53  * # 4-byte binary version number 1.0.7.10 with the name 'main/version'
  54  * version = &#x01;&#x00;&#x07;&#x0a;
  55  *
  56  * [extensions/about]
  57  * # The full name of this parameter is 'extensions/about/module'
  58  * module = libabout.so
  59  * @endcode
  60  *
  61  * Values in INI files are stored as strings and the IniFile class expects them to use specific formats if
  62  * the returned value is supposed to be of a different data type. The following list shows the expected format
  63  * of different data types:
  64  *
  65  * @li Bool - '0', 'false', 'off', 'no' are equal to false and '1', 'true', 'on', 'yes' are equal to true;
  66  * @li Char - a single character or an UTF-16 code as '\0NNNNNN' (oct) or '\0xNNNN' (hex);
  67  * @li Date - date string in the ISO 8601 format YYYY-MM-DD;
  68  * @li DateTime - date and time string in the ISO 8601 format YYY-MM-DDTHH:MM:SSTZD;
  69  * @li Double - the decimal point is always '.' regardless of the locale;
  70  * @li Int - only base 10 (decimal) is allowed;
  71  * @li Time - 24h time string in the format HH:MM:SS
  72  * @li UInt - base 16 (hex) if the string is prefixed with '0x'; base 8 if the string starts with '0'; otherwise
  73  * the value is expected to be base 10 (decimal);
  74  * @li ByteArray - non-printable bytes and special characters are encoded as numeric character or character entity references;
  75  * @li String - non-printable and special characters are encoded as numeric character or character entity references.
  76  *
  77  * Strings and Byte array values can be enclosed in single or double quotes. The IniFile class does this automatically when
  78  * saving String or Byte array values with leading or trailing spaces. Quotes are removed from the parameter value prior
  79  * returning the value to the application. Use character entity references "&quot;" and "&apos;" if quotes should be part of
  80  * the parameter value.
  81  */
  82 class COMMON_EXPORT IniFile
  83 {
  84 public:
  85
  86     /**
  87      * Creates the INI file object
  88      * @param fileName Name of the INI file
  89      * @param mode File opening mode
  90      */
  91     IniFile(QString const & fileName, QIODevice::OpenMode mode = QIODevice::ReadWrite);
  92
  93     /// Dtor
  94     ~IniFile();
  95
  96     /**
  97      * Returns true if the object is valid
  98      *
  99      * The isValid() method returns true if the INI file is can be used. Use this
 100      * method after creating the object to verify that opening the INI file in the specified
 101      * mode succeeded.
 102      */
 103     bool isValid() const;
 104
 105     /**
 106      * Returns the last error message.
 107      *
 108      * The errorString() method returns a human-readable error message if an operation with the INI file failed.
 109      */
 110     QString errorString() const;
 111
 112     /**
 113      * Reads a value from the INI file.
 114      * @param paramName Name of the parameter
 115      * @param defaultValue Default value returned if the parameter value cannot be read
 116      * @return The value from the INI file or an invalid QVariant if failed
 117      *
 118      * The getValue() method reads a parameter value from the INI file. Parameters are identified by a section and key name pair
 119      * in the format '\<section\>/\<key\>'. For example, if the section is called 'general' and the key is called 'log_level',
 120      * then the name of the parameter should be given as 'general/log_level'. Parameter names are case insensitive.
 121      *
 122      * If the parameter cannot be read because it is not found in the INI file or the INI file object is invalid, returns the
 123      * default value. If reading the parameter fails by any other reasons, returns an invalid QVariant value (QVariant::Invalid).
 124      *
 125      * If the default value is of a valid and known QVariant type, then its type is used to validate and optionally convert
 126      * the string read from the INI file. For example:
 127      * @li If the value in the INI file is 'abc' and the default value an integer value, then validation
 128      * fails and the method returns the default value;
 129      * @li If the default value is a boolean value, then the method accepts '1', 'true', 'on' and 'yes' as valid values.
 130      *
 131      * @sa eVaf::Common::toVariant()
 132      */
 133     QVariant getValue(QByteArray const & paramName, QVariant const & defaultValue = QVariant::Invalid);
 134
 135     /**
 136      * Writes a value to the INI file.
 137      * @param paramName Name of the parameter
 138      * @param value The value of the value
 139      * @return True if succeeded and false if not
 140      *
 141      * The setValue() method writes a parameter value to the INI file. Parameters are identified by a section and key name pair
 142      * in the format '\<section\>/\<key\>'. For example, if the section is called 'general' and the key is called 'log_level',
 143      * the the name of the parameter should be given as 'general/log_level'. Parameter names are case insensitive.
 144      *
 145      * The method returns true if the parameter value was written into the INI file and false if not. Use the errorString() method
 146      * to get a human-readable error string if writing to the INI file fails.
 147      */
 148     bool setValue(QByteArray const & paramName, QVariant const & value);
 149
 150
 151 private:
 152
 153     /// Pointer to the internal implementation of the class
 154     QScopedPointer<Internal::IniFileImpl> d;
 155
 156 };
 157
 158 } // namespace eVaf::Common
 159 } // namespace eVaf
 160
 161 #endif // inifile.h