linking properties in object oriented code

I have an object oriented code where I want to be able to link several properties in several manners. e.g. "these properties are always equal", "these properties maintain a ratio of 5" etc. these are not properites of the same object, and sometimes not of objects from the same class.

I was thinking of using linkprop but it is not recommended for objects other than graphic objects. also to the best of my knowledge it can only link properties as equal.

I was thinking of adding postset listeners to the properties where the callback function changes the other properties accordingly, but I am not sure how to prevent recursive calling. i.e one function changes the other property changing the first one etc.

would be thankfull for any assistance

Nathan

Answer 1

[TADA]

it is possible using Post set events.

I am working on an MVVM toolbox which relies on post set events (TaDuAs/Flow: Framework for matlab (github.com))

heres an example which uses a similar notion

The attachment has 3 classes:

ObjectA - a generic handle class with set-observable properties

PropertyBinding - represents a single bound object, its property and an update function

PropertyBinder - manages the bindings for a list of objects.

How to use:

% a simple binding example which copies the values of specified proeprties
% between the objects in the list.
list = {ObjectA(), ObjectA(), ObjectA()};
props = {'X', 'X', 'Y'};
pb = PropertyBinder(list, props);

list{1}.X = 100;
list{1}

ans = 
  ObjectA with properties:

    X: 100
    Y: []
    Z: []

list{2}

ans = 
  ObjectA with properties:

    X: 100
    Y: []
    Z: []

list{3}

ans = 
  ObjectA with properties:

    X: []
    Y: 100
    Z: []

% a more complex relationship, where some of the bindings copy the value
% as-is and some alter the copied value
list2 = {ObjectA(), ObjectA(), ObjectA()};
props2 = {'X', 'X', 'Y'};
pb2(1) = PropertyBinder(list([1,3]), props([1,3]), {@(x) x/5, @(x) x*5});
pb(2) = PropertyBinder(list([2,3]), props([2,3]), {@(x) x/5, @(x) x*5})

pb = 
  1×2 PropertyBinder array with properties:

    Bindings
    Listeners

pb(3) = PropertyBinder(list(1:2), props(1:2));

list{1}.X = 100;
list{1}

ans = 
  ObjectA with properties:

    X: 100
    Y: []
    Z: []

list{2}

ans = 
  ObjectA with properties:

    X: 100
    Y: []
    Z: []

list{3}

ans = 
  ObjectA with properties:

    X: []
    Y: 500
    Z: []