MATLAB Object-Oriented Programming

events

UpdateGraph

end

Determine When to Trigger Event

The fcneval class defines a property set method for the FofXY property. FofXY is the

property that stores the MATLAB expression for the mathematical function. This

expression must be a valid MATLAB expression for a function of two variables.

The set.FofXY method:

• Determines the suitability of the expression


• If the expression is suitable:
  
  
  • Assigns the expression to the FofXY property
  
  
  • Triggers the UpdateGraph event
  
  
  
  

If fcneval.isSuitable does not return an MException object, the set.FofXY

method assigns the value to the property and triggers the UpdateGraph event.

function set.FofXY(obj,func)

% Determine if function is suitable to create a surface

me = fcneval.isSuitable(func);

if ~isempty(me)

throw(me)

end

% Assign property value

obj.FofXY = func;

% Trigger UpdateGraph event

notify(obj,'UpdateGraph');

end

Determine Suitability of Expression

The set.FofXY method calls a static method (fcneval.isSuitable) to determine the

suitability of the specified expression. fcneval.isSuitable returns an MException

object if it determines that the expression is unsuitable. fcneval.isSuitable calls the

MException constructor directly to create more useful error messages for the user.

set.FofXY issues the exception using the MException.throw method. Issuing the

exception terminates execution of set.FofXY and prevents the method from making an

assignment to the property or triggering the UpdateGraph event.

11 Events — Sending and Responding to Messages