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/*
cpptempl
=================
This is a template engine for C++.
Syntax
=================
Variables: {$variable_name}
Loops: {% for person in people %}Name: {$person.name}{% endfor %}
If: {% for person.name == "Bob" %}Full name: Robert{% endif %}
Copyright
==================
Author: Ryan Ginstrom
MIT License
Usage
=======================
std::string text = "{% if item %}{$item}{% endif %}\n"
"{% if thing %}{$thing}{% endif %}" ;
cpptempl::data_map data ;
data["item"] = cpptempl::make_data("aaa") ;
data["thing"] = cpptempl::make_data("bbb") ;
std::string result = cpptempl::parse(text, data) ;
Handy Functions
========================
make_data() : Feed it a string, data_map, or data_list to create a data entry.
Example:
data_map person ;
person["name"] = make_data("Bob") ;
person["occupation"] = make_data("Plumber") ;
data_map data ;
data["person"] = make_data(person) ;
std::string result = parse(templ_text, data) ;
*/
#pragma once
#ifdef _WIN32
#pragma warning( disable : 4996 ) // 'std::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators'
#pragma warning( disable : 4512 ) // 'std::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators'
#endif
#include <string>
#include <vector>
#include <map>
#include <memory>
#include <unordered_map>
#include <boost/lexical_cast.hpp>
#include <iostream>
namespace cpptempl
{
// various typedefs
// data classes
class Data ;
class DataValue ;
class DataList ;
class DataMap ;
class data_ptr {
public:
data_ptr() {}
template<typename T> data_ptr(const T& data) {
this->operator =(data);
}
data_ptr(DataValue* data);
data_ptr(DataList* data);
data_ptr(DataMap* data);
data_ptr(const data_ptr& data) {
ptr = data.ptr;
}
template<typename T> void operator = (const T& data);
void push_back(const data_ptr& data);
virtual ~data_ptr() {}
Data* operator ->() {
return ptr.get();
}
private:
std::shared_ptr<Data> ptr;
};
typedef std::vector<data_ptr> data_list ;
class data_map {
public:
data_ptr& operator [](const std::string& key);
bool empty();
bool has(const std::string& key);
private:
std::unordered_map<std::string, data_ptr> data;
};
template<> inline void data_ptr::operator = (const data_ptr& data);
template<> void data_ptr::operator = (const std::string& data);
template<> void data_ptr::operator = (const std::string& data);
template<> void data_ptr::operator = (const data_map& data);
template<typename T>
void data_ptr::operator = (const T& data) {
std::string data_str = boost::lexical_cast<std::string>(data);
this->operator =(data_str);
}
// token classes
class Token ;
typedef std::shared_ptr<Token> token_ptr ;
typedef std::vector<token_ptr> token_vector ;
// Custom exception class for library errors
class TemplateException : public std::exception
{
public:
TemplateException(std::string reason) : m_reason(reason){}
~TemplateException() {}
const char* what() const noexcept {
return m_reason.c_str();
}
private:
std::string m_reason;
};
// Data types used in templates
class Data
{
public:
virtual ~Data() {}
virtual bool empty() = 0 ;
virtual std::string getvalue();
virtual data_list& getlist();
virtual data_map& getmap() ;
};
class DataValue : public Data
{
std::string m_value ;
public:
DataValue(std::string value) : m_value(value){}
std::string getvalue();
bool empty();
};
class DataList : public Data
{
data_list m_items ;
public:
DataList(const data_list &items) : m_items(items){}
data_list& getlist() ;
bool empty();
};
class DataMap : public Data
{
data_map m_items ;
public:
DataMap(const data_map &items) : m_items(items){}
data_map& getmap();
bool empty();
};
// convenience functions for making data objects
inline data_ptr make_data(std::string val)
{
return data_ptr(new DataValue(val)) ;
}
inline data_ptr make_data(data_list &val)
{
return data_ptr(new DataList(val)) ;
}
inline data_ptr make_data(data_map &val)
{
return data_ptr(new DataMap(val)) ;
}
// get a data value from a data map
// e.g. foo.bar => data["foo"]["bar"]
data_ptr parse_val(std::string key, data_map &data) ;
typedef enum
{
TOKEN_TYPE_NONE,
TOKEN_TYPE_TEXT,
TOKEN_TYPE_VAR,
TOKEN_TYPE_IF,
TOKEN_TYPE_FOR,
TOKEN_TYPE_ENDIF,
TOKEN_TYPE_ENDFOR,
} TokenType;
// Template tokens
// base class for all token types
class Token
{
public:
virtual ~Token() {};
virtual TokenType gettype() = 0 ;
virtual void gettext(std::ostream &stream, data_map &data) = 0 ;
virtual void set_children(token_vector &children);
virtual token_vector & get_children();
};
// normal text
class TokenText : public Token
{
std::string m_text ;
public:
TokenText(std::string text) : m_text(text){}
TokenType gettype();
void gettext(std::ostream &stream, data_map &data);
};
// variable
class TokenVar : public Token
{
std::string m_key ;
public:
TokenVar(std::string key) : m_key(key){}
TokenType gettype();
void gettext(std::ostream &stream, data_map &data);
};
// for block
class TokenFor : public Token
{
public:
std::string m_key ;
std::string m_val ;
token_vector m_children ;
TokenFor(std::string expr);
TokenType gettype();
void gettext(std::ostream &stream, data_map &data);
void set_children(token_vector &children);
token_vector &get_children();
};
// if block
class TokenIf : public Token
{
public:
std::string m_expr ;
token_vector m_children ;
TokenIf(std::string expr) : m_expr(expr){}
TokenType gettype();
void gettext(std::ostream &stream, data_map &data);
bool is_true(std::string expr, data_map &data);
void set_children(token_vector &children);
token_vector &get_children();
};
// end of block
class TokenEnd : public Token // end of control block
{
std::string m_type ;
public:
TokenEnd(std::string text) : m_type(text){}
TokenType gettype();
void gettext(std::ostream &stream, data_map &data);
};
std::string gettext(token_ptr token, data_map &data) ;
void parse_tree(token_vector &tokens, token_vector &tree, TokenType until=TOKEN_TYPE_NONE) ;
token_vector & tokenize(std::string text, token_vector &tokens) ;
// The big daddy. Pass in the template and data,
// and get out a completed doc.
void parse(std::ostream &stream, std::string templ_text, data_map &data) ;
std::string parse(std::string templ_text, data_map &data);
std::string parse(std::string templ_text, data_map &data);
}