visit_context.cpp

/**
 * @file
 *
 * @brief
 *
 * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
 */

#include "visit_context.hpp"
#include <kdb.hpp>

#include <iostream>

class CountryAustriaLayer : public kdb::Layer
{
public:
	std::string id() const { return "country"; }
	std::string operator()() const { return "Austria"; }
};

class LanguageGermanLayer : public kdb::Layer
{
public:
	std::string id() const override
	{
		return "language";
	}
	std::string operator()() const override
	{
		return "german";
	}
};

class ProfileLayer : public kdb::Layer
{
public:
	ProfileLayer(kdb::visit::Profile const & profile) :
		m_profile(profile) {}
	std::string id() const { return "profile"; }
	std::string operator()() const { return m_profile; }
private:
	kdb::visit::Profile const & m_profile;
};
//{end}

/*
//{layer/profileOld}
class ProfileLayer : public kdb::Layer
{
public:
	ProfileLayer(kdb::String const & profile) :
		m_profile(profile) {}
	std::string id() const override
	{ return "profile"; }
	std::string operator()() const override
	{ return m_profile; }
private:
	std::string m_profile;
};
//{end}
*/

// application: e.g. git-pull, git-push
//{application}
class MainApplicationLayer : public kdb::Layer
{
public:
	std::string id() const override
	{ return "application"; }
	std::string operator()() const override
	{ return "main"; }
};

void visit(kdb::visit::Person & p) {
	p.context().with<CountryAustriaLayer>()
		   .with<LanguageGermanLayer>()([&] {
		std::cout << "visit " << ++p.visits << " in "
				  << p.context()["country"] << ": "
				  << p.greeting << std::endl; });
	std::cout << p.greeting << std::endl;
}

int main()
{
	using namespace kdb;

	KDB kdb;
	KeySet ks;
	Context c;
	// some predefined values (for convenience):
	ks.append(Key("user/visit/%/%/%/person/greeting",
				   KEY_VALUE,
				   "Tag",
				   KEY_END));
	ks.append(Key("user/visit/german/Austria/%/person/greeting",
				   KEY_VALUE,
				   "Servus",
				   KEY_END));
	ks.append(Key("user/visit/german/switzerland/%/person/greeting",
				   KEY_VALUE,
				   "Grüezi",
				   KEY_END));
	KeySet ks2;
	kdb.get(ks2, "/visit");
	// overwrite them if something is available in config files:
	ks.append(ks2);

	Parameters par(ks,c);

	c.activate<MainApplicationLayer>();
	c.activate<ProfileLayer>(par.profile);

	for (int i=0; i<3; ++i) ::visit(par.visit.person);

	return 0;
}