Customize Property Display

Objective

Change the order and number of properties displayed for an object of your class.

Change the Property Order

Suppose your class definition contains the following property definition:

properties
      Name
      JobTitle
      Department
      Salary
      Password
end

In the default scalar object display, MATLAB^® displays all the public properties along with their values. However, you want to display only Department, JobTitle, and Name, in that order. You can do this by deriving from CustomDisplay and overriding the getPropertyGroups method.

Your override

• Defines method Access as protected to match the definition in the CustomDisplay superclass

• Creates a cell array of property names in the desired order

• Returns a PropertyGroup object constructed from the property list cell array

methods (Access = protected)
   function propgrp = getPropertyGroups(~)
      proplist = {'Department','JobTitle','Name'};
      propgrp = matlab.mixin.util.PropertyGroup(proplist);
   end
end

When you create a PropertyGroup object using a cell array of property names, MATLAB automatically

• Adds the property values for a scalar object display

• Uses the property names without values for a nonscalar object display (including empty object arrays)

The getPropertyGroups method is not called to create the display for a scalar handle to a deleted object.

Change the Values Displayed for Properties

Given the same class properties used in the previous section, you can change the value displayed for properties by building the property list as a struct and specifying values for property names. This override of the getPropertyGroups method uses the default property display for nonscalar objects by calling the superclass getPropertyGroups method. For scalar objects, the override:

• Changes the value displayed for the Password property to a '*' character for each character in the password.

• Displays the text 'Not Available' for the Salary property.

methods (Access = protected)
   function propgrp = getPropertyGroups(obj)
      if ~isscalar(obj)
         propgrp = [e-mail](obj);
      else
         pd(1:length(obj.Password)) = '*';
         propList = struct('Department',obj.Department,...
            'JobTitle',obj.JobTitle,...
            'Name',obj.Name,...
            'Salary','Not available',...
            'Password',pd);
         propgrp = matlab.mixin.util.PropertyGroup(propList);
      end
   end
end

The object display looks like this:

  EmployeeInfo with properties:

    Department: 'Product Development'
      JobTitle: 'Software Engineer'
          Name: 'Bill Tork'
        Salary: 'Not available'
      Password: '*******'

 Full Class Listing

classdef EmployeeInfo < handle & matlab.mixin.CustomDisplay
   properties
      Name
      JobTitle
      Department
      Salary
      Password
   end
   methods
      function obj = EmployeeInfo
         obj.Name       = input('Name: ');
         obj.JobTitle   = input('Job Title: ');
         obj.Department = input('Department: ');
         obj.Salary     = input('Salary: ');
         obj.Password   = input('Password: ');
      end
   end
   methods (Access = protected)
      function propgrp = getPropertyGroups(obj)
         if ~isscalar(obj)
            propgrp = [e-mail](obj);
         else
            pd(1:length(obj.Password)) = '*';
            propList = struct('Department',obj.Department,...
               'JobTitle',obj.JobTitle,...
               'Name',obj.Name,...
               'Salary','Not available',...
               'Password',pd);
            propgrp = matlab.mixin.util.PropertyGroup(propList);
         end
      end
   end
end