solidity/libdevcore/Whiskers.h
2019-07-04 09:31:24 +02:00

112 lines
3.5 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file Whiskers.h
* @author Chris <chis@ethereum.org>
* @date 2017
*
* Moustache-like templates.
*/
#pragma once
#include <libdevcore/Exceptions.h>
#include <string>
#include <map>
#include <vector>
namespace dev
{
DEV_SIMPLE_EXCEPTION(WhiskersError);
/**
* Moustache-like templates.
*
* Usage:
* std::vector<std::map<std::string, std::string>> listValues(2);
* listValues[0]["k"] = "key1";
* listValues[0]["v"] = "value1";
* listValues[1]["k"] = "key2";
* listValues[1]["v"] = "value2";
* auto s = Whiskers("<?c><p1><!c>y</c>\n<#list><k> -> <v>\n</list>")
* ("p1", "HEAD")
* ("c", true)
* ("list", listValues)
* .render();
*
* results in s == "HEAD\nkey1 -> value1\nkey2 -> value2\n"
*
* Note that lists cannot themselves contain lists - this would be a future feature.
*
* The elements are:
* - Regular parameter: <name>
* just replaced
* - Condition parameter: <?name>...<!name>...</name>, where "<!name>" is optional
* replaced (and recursively expanded) by the first part if the condition is true
* and by the second (or empty string if missing) if the condition is false
* - List parameter: <#list>...</list>
* The part between the tags is repeated as often as values are provided
* in the mapping. Each list element can have its own parameter -> value mapping.
*/
class Whiskers
{
public:
using StringMap = std::map<std::string, std::string>;
using StringListMap = std::map<std::string, std::vector<StringMap>>;
explicit Whiskers(std::string _template);
/// Sets a single regular parameter, <paramName>.
Whiskers& operator()(std::string _parameter, std::string _value);
Whiskers& operator()(std::string _parameter, char const* _value) { return (*this)(_parameter, std::string{_value}); }
/// Sets a condition parameter, <?paramName>...<!paramName>...</paramName>
Whiskers& operator()(std::string _parameter, bool _value);
/// Sets a list parameter, <#listName> </listName>.
Whiskers& operator()(
std::string _listParameter,
std::vector<StringMap> _values
);
std::string render() const;
private:
// Prevent implicit cast to bool
Whiskers& operator()(std::string _parameter, long long);
void checkParameterValid(std::string const& _parameter) const;
void checkParameterUnknown(std::string const& _parameter) const;
static std::string replace(
std::string const& _template,
StringMap const& _parameters,
std::map<std::string, bool> const& _conditions,
StringListMap const& _listParameters = StringListMap()
);
static std::string paramRegex() { return "[a-zA-Z0-9_$-]+"; }
/// Joins the two maps throwing an exception if two keys are equal.
static StringMap joinMaps(StringMap const& _a, StringMap const& _b);
std::string m_template;
StringMap m_parameters;
std::map<std::string, bool> m_conditions;
StringListMap m_listParameters;
};
}