Setter methods for dynamic properties

Question

Andrew Barton 2012-9-18

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/48406-setter-methods-for-dynamic-properties

Hello,

I have been working with a class that has dynamic properties that I would like to have setter methods for. The problem is that I don't know how many or the names of the dynamic properties, so I want to have just one setter that takes the name of the property as an argument. However this breaks the part of MATLAB that determines whether or not you're in a setter function (so that when you set the variable it just sets the variable, instead of calling the setter recursively). Here's some example code that illustrates what I'm talking about:

classdef myClass < dynamicprops
    methods
        function obj = myClass()
            P = addprop(obj, 'myProp');
            P.SetMethod = @(o,p)SetProp(o,'myProp',p);
        end
          function SetProp(obj, propname, val)
              obj.(propname) = val;
          end
      end
  end

Now if you try:

x = myClass();
x.myProp = 7;

the method SetProp gets called recursively until MATLAB throws an error. Is there another way to go about this that I am missing? Thanks in advance.

-Andrew

3 个评论
显示 1更早的评论隐藏 1更早的评论

Andrew Barton 2012-9-19

Not quite, I'd really like the user of the class to be able to assign the property using normal syntax, i.e:

x.someprop = value

Jim Hokanson 2013-6-10

See Also:

http://www.mathworks.com/matlabcentral/answers/48831-set-methods-for-dynamic-properties-with-unknown-names

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Daniel Shub 2012-9-19

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/48406-setter-methods-for-dynamic-properties#answer_59346

在 MATLAB Online 中打开

What about overloading subsasgn

classdef myClass < dynamicprops
    methods
        function obj = myClass()
            P = addprop(obj, 'myProp');
        end
    function A = subsasgn(A, S, B)
      switch S.type
        case '.'
          SetProp(A, S.subs, B);
      end
    end
      
          function SetProp(obj, propname, val)
              obj.(propname) = val;
          end
      end
  end

2 个评论
显示无隐藏无

Andrew Barton 2012-9-19

Thanks for the idea, that looks like it would fix my problem, but it also seems like it would force me to reimplement normal array indexing for S.type case '()' which I would obviously rather avoid.

I really think there must be a way to pass the name of the property assigned to the SetMethod function, otherwise attaching SetMethods to dynamic properties would be completely useless in all cases.

Andrew Barton 2012-9-20