MATLAB Object-Oriented Programming

Dynamic Properties and ConstructOnLoad

Setting the class ConstructOnLoad attribute to true causes MATLAB to call the class

constructor when loading the class. MATLAB saves and restores dynamic properties when

loading an object.

If you create dynamic properties from the class constructor, you can cause a conflict if

you also set the class ConstructOnLoad attribute to true. Here is the sequence:

• A saved object saves the names and values of properties, including dynamic properties


• When loaded, a new object is created and all properties are restored to the values at
  the time the object was saved


• Then, the ConstructOnLoad attribute causes a call to the class constructor, which
  would create another dynamic property with the same name as the loaded property.
  See “Save and Load Objects” on page 13-2 for more on the load sequence.


• MATLAB prevents a conflict by loading the saved dynamic property, and does not
  execute addprop when calling the constructor.

If you use ConstructOnLoad, add dynamic properties from the class constructor, and

want the constructor to call addprop at load time, then set the dynamic property

Transient attribute to true. This setting prevents the property from being saved. For

example:

classdef (ConstructOnLoad) MyClass < dynamicprops

function obj = MyClass

P = addprop(obj,'DynProp');

P.Transient = true;

...

end

end

See Also

Related Examples

• “Dynamic Properties — Adding Properties to an Instance” on page 8-69

8 Properties — Storing Class Data