Matlab责任链模式

责任链模式（chain of responsibility pattern）为请求创建了一个接收者对象的链。这种模式给予请求的类型，对请求的发送者和接收者进行解耦，本人根据https://www.runoob.com/design-pattern/chain-of-responsibility-pattern.html所给的例子，用matlab代码实现责任链模式

abstractlogger.m

classdef abstractlogger < handle & matlab.mixin.heterogeneous
    properties(constant)
        info = 1;
        debug = 2;
        error = 3;
    end
    properties(access = protected)
        level
        nextlogger = abstractlogger.empty();
    end
    methods(abstract,access = protected)
        write(~);
    end
    methods
        function setnextlogger(obj,nextlogger)
            obj.nextlogger = nextlogger;
        end
        
        function logmessage(obj,level,message)
            if(obj.level <= level)
                obj.write(message);
            end
            if ~isempty(obj.nextlogger)
                obj.nextlogger.logmessage(level, message);
            end
        end
    end
end

　consolelogger.m

classdef consolelogger < abstractlogger
    methods
        function obj=consolelogger(level)
            obj.level = level;
        end
    end
    methods(access = protected)
        function write(~,message)
            disp("standard console::logger: " + message);
        end
    end
end

　filelogger.m

classdef filelogger < abstractlogger
    methods
        function obj=filelogger(level)
            obj.level = level;
        end
    end
    methods(access = protected)
        function write(~,message)
            disp("file console::logger: " + message);
        end
    end   
end

　errorlogger.m

classdef errorlogger < abstractlogger
    methods
        function obj=errorlogger(level)
            obj.level = level;
        end
    end
    methods(access = protected)
        function write(~,message)
            disp("error console::logger: " + message);
        end
    end
end

　测试代码：

errorlogger = errorlogger(abstractlogger.error);
filelogger = filelogger(abstractlogger.debug);
consolelogger = consolelogger(abstractlogger.info);

errorlogger.setnextlogger(filelogger);
filelogger.setnextlogger(consolelogger);
 
loggerchain = errorlogger;
loggerchain.logmessage(abstractlogger.info, "this is an information.");
loggerchain.logmessage(abstractlogger.debug, "this is a debug level information.");
loggerchain.logmessage(abstractlogger.error, "this is an error information.");