vaikene.ee Git - evaf/blob - src/libs/Common/inifile.h

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