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Diffstat (limited to 'zenxml/cvrt_text.h')
| -rw-r--r-- | zenxml/cvrt_text.h | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/zenxml/cvrt_text.h b/zenxml/cvrt_text.h new file mode 100644 index 00000000..a70c0813 --- /dev/null +++ b/zenxml/cvrt_text.h @@ -0,0 +1,229 @@ +// ************************************************************************** +// * This file is part of the zenXML project. It is distributed under the * +// * Boost Software License: http://www.boost.org/LICENSE_1_0.txt * +// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved * +// ************************************************************************** + +#ifndef ZEN_XML_CONVERT_TEXT_HEADER_018727339083427097434 +#define ZEN_XML_CONVERT_TEXT_HEADER_018727339083427097434 + +#include <zen/utf.h> +#include <zen/string_tools.h> + +namespace zen +{ +/** +\file +\brief Handle conversion of string-convertible types to and from std::string. + +It is \b not required to call these functions directly. They are implicitly used by zen::XmlElement::getValue(), +zen::XmlElement::setValue(), zen::XmlElement::getAttribute() and zen::XmlElement::setAttribute(). +\n\n +Conversions for the following user types are supported by default: + - strings - std::string, std::wstring, char*, wchar_t*, char, wchar_t, ect..., all STL-compatible-string-classes + - numbers - int, double, float, bool, long, ect..., all built-in numbers + - STL containers - std::map, std::set, std::vector, std::list, ect..., all STL-compatible-containers + - std::pair + +You can add support for additional types via template specialization. \n\n +Specialize zen::readStruc() and zen::writeStruc() to enable conversion from structured user types to XML elements. +Specialize zen::readText() and zen::writeText() to enable conversion from string-convertible user types to std::string. +Prefer latter if possible since it does not only enable conversions from XML elements to user data, but also from and to XML attributes. +\n\n +<b> Example: </b> type "bool" +\code +namespace zen +{ +template <> inline +void writeText(const bool& value, std::string& output) +{ + output = value ? "true" : "false"; +} + +template <> inline +bool readText(const std::string& input, bool& value) +{ + std::string tmp = input; + zen::trim(tmp); + if (tmp == "true") + value = true; + else if (tmp == "false") + value = false; + else + return false; + return true; +} +} +\endcode +*/ + + +///Convert text to user data - used by XML elements and attributes +/** + \param input Input text. + \param value Conversion target value. + \return "true" if value was read successfully. +*/ +template <class T> bool readText(const std::string& input, T& value); +///Convert user data into text - used by XML elements and attributes +/** + \param value The value to be converted. + \param output Output text. +*/ +template <class T> void writeText(const T& value, std::string& output); + + +/* Different classes of data types: + +--------------------------- +| structured | readStruc/writeStruc - e.g. string-convertible types, STL containers, std::pair, structured user types +| ---------------------- | +| | string-convertible | | readText/writeText - e.g. string-like types, all built-in arithmetic numbers, bool +| | --------------- | | +| | | string-like | | | utfCvrtTo - e.g. std::string, wchar_t*, char[], wchar_t, wxString, MyStringClass, ... +| | --------------- | | +| ---------------------- | +--------------------------- +*/ + + + + + + + + + + + + + + + + + + + + + + +//------------------------------ implementation ------------------------------------- + +//Conversion from arbitrary types to text (for use with XML elements and attributes) +enum TextType +{ + TEXT_TYPE_BOOL, + TEXT_TYPE_NUMBER, + TEXT_TYPE_STRING, + TEXT_TYPE_OTHER, +}; + +template <class T> +struct GetTextType : StaticEnum<TextType, + IsSameType<T, bool>::value ? TEXT_TYPE_BOOL : + IsStringLike<T>::value ? TEXT_TYPE_STRING : //string before number to correctly handle char/wchar_t -> this was an issue with Loki only! + IsArithmetic<T>::value ? TEXT_TYPE_NUMBER : // + TEXT_TYPE_OTHER> {}; + +//###################################################################################### + +template <class T, TextType type> +struct ConvertText; +/* -> expected interface +{ + void writeText(const T& value, std::string& output) const; + bool readText(const std::string& input, T& value) const; +}; +*/ + +//partial specialization: type bool +template <class T> +struct ConvertText<T, TEXT_TYPE_BOOL> +{ + void writeText(bool value, std::string& output) const + { + output = value ? "true" : "false"; + } + bool readText(const std::string& input, bool& value) const + { + std::string tmp = input; + zen::trim(tmp); + if (tmp == "true") + value = true; + else if (tmp == "false") + value = false; + else + return false; + return true; + } +}; + +//partial specialization: handle conversion for all built-in arithmetic types! +template <class T> +struct ConvertText<T, TEXT_TYPE_NUMBER> +{ + void writeText(const T& value, std::string& output) const + { + output = numberTo<std::string>(value); + } + bool readText(const std::string& input, T& value) const + { + value = stringTo<T>(input); + return true; + } +}; + +//partial specialization: handle conversion for all string-like types! +template <class T> +struct ConvertText<T, TEXT_TYPE_STRING> +{ + void writeText(const T& value, std::string& output) const + { + output = utfCvrtTo<std::string>(value); + } + bool readText(const std::string& input, T& value) const + { + value = utfCvrtTo<T>(input); + return true; + } +}; + + +//partial specialization: unknown type +template <class T> +struct ConvertText<T, TEXT_TYPE_OTHER> +{ + //########################################################################################################################################### + assert_static(sizeof(T) == -1); + /* + ATTENTION: The data type T is yet unknown to the zenXML framework! + + Please provide a specialization for T of the following two functions in order to handle conversions to XML elements and attributes + + template <> void zen::writeText(const T& value, std::string& output) + template <> bool zen::readText(const std::string& input, T& value) + + If T is structured and cannot be converted to a text representation specialize these two functions to allow at least for conversions to XML elements: + + template <> void zen::writeStruc(const T& value, XmlElement& output) + template <> bool zen::readStruc(const XmlElement& input, T& value) + */ + //########################################################################################################################################### +}; + + +template <class T> inline +void writeText(const T& value, std::string& output) +{ + ConvertText<T, GetTextType<T>::value>().writeText(value, output); +} + + +template <class T> inline +bool readText(const std::string& input, T& value) +{ + return ConvertText<T, GetTextType<T>::value>().readText(input, value); +} +} + +#endif //ZEN_XML_CONVERT_TEXT_HEADER_018727339083427097434 |