MATLAB Programming Fundamentals - MathWorks

Set Property Values at Construction Time

This example shows how to define a System object constructor and allow it to accept

name-value property pairs as input.

Set Properties to Use Name-Value Pair Input

Define the System object constructor, which is a method that has the same name as the

class (MyFile in this example). Within that method, you use the setProperties method

to make all public properties available for input when the user constructs the object.

nargin is a MATLAB function that determines the number of input arguments. varargin

indicates all of the object’s public properties.

methods

function obj = MyFile(varargin)

setProperties(obj,nargin,varargin{:});

end

end

Complete Class Definition File with Constructor Setup

classdef MyFile < matlab.System

% MyFile write numbers to a file

% These properties are nontunable. They cannot be changed

% after the setup method has been called or while the

% object is running.

properties (Nontunable)

Filename ="default.bin" % the name of the file to create

Access = 'wb' % The file access character vector (write, binary)

end

% These properties are private. Customers can only access

% these properties through methods on this object

properties (Hidden,Access = private)

pFileID; % The identifier of the file to open

end

methods

% You call setProperties in the constructor to let

% a user specify public properties of object as

% name-value pairs.

function obj = MyFile(varargin)

setProperties(obj,nargin,varargin{:});

34 System object Usage and Authoring