我正在尝试根据 Bob Martin 叔叔在这里描述的 Clean Architecture 概念用 C++ (C++11) 编写一个非常简单的示例（下图）：
这个想法是由控制器读取一些文本并由演示者打印。我做了一些事情，但它看起来不像是遵循干净的流程和博客文章的DIP。
除其他外，我认为流程是错误的，例如，IUseCaseInputPort 需要了解 IUseCaseOutputPort（读取函数将 IUseCaseOutputPort 作为输入参数，因此创建了另一个依赖项......）。
如果有人能给我一些关于实现这一点的最佳方法的提示，我将不胜感激。提前谢谢了。
#include <iostream>
#include <string>
#include <memory>
class IUseCaseOutputPort {
public:
virtual void print(std::string message) = 0;
virtual ~IUseCaseOutputPort() {};
};
// 2 Presenters
class HtmlPresenter: public IUseCaseOutputPort {
public:
void print(std::string message) {
std::cout << "<p>" << message << "</p>" << std::endl;
}
};
class TextPresenter: public IUseCaseOutputPort {
public:
void print(std::string message) {
std::cout << message << std::endl;
}
};
//
class IUseCaseInputPort {
public:
virtual void read(std::shared_ptr<IUseCaseOutputPort> output) = 0;
virtual ~IUseCaseInputPort(){};
};
// specific UseCaseInteractor
class UseCaseInteractorForInputFromStdIn: public IUseCaseInputPort {
public:
void read(std::shared_ptr<IUseCaseOutputPort> output) {
std::string message;
std::cout << "Please input some text!";
std::getline(std::cin, message);
output->print(message);
}
};
// Controller
class ControllerToDisplayHtml {
public:
void displayInHtmlSomethingFromStdIn() {
input = std::make_shared<UseCaseInteractorForInputFromStdIn>();
std::shared_ptr<HtmlPresenter> output =
std::make_shared<HtmlPresenter>();
input->read(output);
}
private:
std::shared_ptr<IUseCaseInputPort> input;
};
int main() {
ControllerToDisplayHtml c;
c.displayInHtmlSomethingFromStdIn();
return 0;
}
对于那些感兴趣的人，可以补充BЈовић建议的我的问题。非常简单的例子。只是为了展示这个模型的流程。
#include <iostream>
#include <string>
#include <memory>
#include <fstream>
class IUseCaseOutputPort {
public:
virtual void print(std::string message) = 0;
virtual ~IUseCaseOutputPort() {};
};
// 2 Presenters
class HtmlPresenter: public IUseCaseOutputPort {
public:
void print(std::string message) {
std::cout << "<p>" << message << "</p>" << std::endl;
}
};
class TextPresenter: public IUseCaseOutputPort {
public:
void print(std::string message) {
std::cout << message << std::endl;
}
};
//
class IUseCaseInputPort {
public:
virtual std::string read() = 0;
virtual ~IUseCaseInputPort(){};
};
// specific UseCaseInteractor for reading text from the stdin
class UseCaseInteractorForInputFromStdIn: public IUseCaseInputPort {
public:
std::string read() {
std::string message;
std::cout << "Please input some text!" << std::endl;
std::getline(std::cin, message);
return message;
}
};
// specific UseCaseInteractor for reading text from a dummy file
class UseCaseInteractorForInputFromDummyFile: public IUseCaseInputPort {
public:
std::string read() {
const std::string filename = "/proc/meminfo";
std::string message = readFile(filename);
return message;
}
private:
std::string readFile(const std::string filename) {
std::string line;
std::string lines;
std::ifstream myfile(filename);
if (myfile.is_open()) {
while (myfile.good()) {
getline(myfile, line);
lines += line + '\n';
}
myfile.close();
} else {
lines = "Unable to open file";
}
return lines;
}
};
// Controller
class ControllerForReading {
public:
std::string readFromStdIn() {
input = std::make_shared<UseCaseInteractorForInputFromStdIn>();
std::string out = "This text was read from the stdin:\n";
out += input->read();
return out;
}
std::string readFromFile() {
input = std::make_shared<UseCaseInteractorForInputFromDummyFile>();
std::string out = "This text was read from the a file:\n";
out += input->read();
return out;
}
private:
std::shared_ptr<IUseCaseInputPort> input;
};
// main represents the outer shell
int main() {
std::cout << "Main started!" << std::endl;
ControllerForReading c;
const std::string textFromStdin = c.readFromStdIn();
const std::string textFromFile = c.readFromFile();
auto output = std::make_shared<HtmlPresenter>();
output->print(textFromStdin);
output->print(textFromFile);
auto output2 = std::make_shared<TextPresenter>();
output2->print(textFromStdin);
output2->print(textFromFile);
std::cout << "Main ended!" << std::endl;
return 0;
}