Classdef: Difference between revisions

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This page is a stub. We should begin documenting what classdef is implemented and what is not.
=== Supported Features ===


=== Not Supported ===
==== Properties ====


* '''enumeration'''
Classdef properties are supported but not all attributes are implemented.


See {{bug|44582}} and help implementing it.
{| class="wikitable"
|-
! style="text-align:left;"| Attribute
! Support
! Notes
|-
|AbortSet
|No
|Property does not exist.
|-
|Abstract
|Yes
|
|-
|Access
|Partial
|
|-
|Constant
|Yes
|
|-
|Dependent
|Partial
|
|-
|GetAccess
|Partial
|
|-
|GetObservable
|No
|Property exists but is not used.  Requires events and listeners to be implemented in order to work properly.
|-
|Hidden
|Yes
|
|-
|NonCopyable
|No
|Property does not exist.
|-
|SetAccess
|Partial
|
|-
|SetObservable
|No
|Property exists but is not used.  Requires events and listeners to be implemented in order to work properly.
|-
|Transient
|No
|Property exists but is not used.
|}


==== Methods ====


* '''build-in class as superclass'''
Classdef methods are supported but not all attributes are fully implemented.
<source lang="octave">
classdef nonsense < uint32


end
{| class="wikitable"
</source>
|-
! style="text-align:left;"| Attribute
! Support
! Notes
|-
|Abstract
|Partial
|See bug report {{bug|51377}}
|-
|Access
|Yes
|
|-
|Hidden
|Yes
|
|-
|Sealed
|Yes
|
|-
|Static
|Yes
|
|}


See {{bug|44035}}
=== Features that are not implemented ===


* '''[http://www.mathworks.com/help/matlab/matlab_oop/redefining-concatenation-for-your-class.html concatenating objects] into [http://www.mathworks.com/help/matlab/matlab_oop/initialize-object-arrays.html array of objects].'''
==== [https://www.mathworks.com/help/matlab/enumeration-classes.html enumeration] ====


Example:
* {{bug|44582}} Parse the enumeration section of a classdef definition but nothing is done with it.
<source lang="octave">
classdef MyClass < handle
end


c = MyClass();
==== [https://www.mathworks.com/help/matlab/matlab_oop/learning-to-use-events-and-listeners.html events and listeners] ====
cc = [c, c];  % won't work
</source>


For now you can use a cell-array of objects instead:
* {{bug|56194}} Parse the events section of a classdef definition but nothing is done with it.
<source lang="octave">
cc = {c, c};  % ok
</source>


Also see {{bug|44665}}
==== [https://www.mathworks.com/help/matlab/matlab_oop/property-validator-functions.html Property Validation Functions] ====


* '''[http://www.mathworks.com/help/matlab/matlab_oop/mutable-and-immutable-properties.html Immutable property] set access.'''
=== Open Bug Reports for Other Issues ===
Example:
<source lang="octave">
classdef MyClass < handle
    properties (SetAccess = immutable)
        x
    end
    methods
        function obj = MyClass()
            x = rand();
        end
    end
end
</source>


Use "private" properties as workaround.
==== Issues with basic classdef functionality ====


* {{bug|51659}} Calling 'methods' on self causes syntax error
* {{bug|48682}} print_usage fails within classdef block
* {{bug|48041}} classdef: `help myclass` messes up `help @myclass/method`
* {{bug|52096}} meta.class.fromName throws error when class name not found.
* {{bug|48693}} classdef subsref method is not called with correct nargout value - <em>Patch applied, Ready for Test</em>
* {{bug|56006}} Object indexing: obj(1).property(end+1:n) - end is interpreted wrong
* {{bug|55983}} 'x(ix) = []' deletion syntax does not work for objects
* {{bug|55976}} cat, repmat, and reshape don't work for classdef objects
* {{bug|55961}} properties function does not preserve order - <em>Patch submitted, awaiting review</em>
* {{bug|52582}} using static method to initialize property value fails
* {{bug|45833}} support load/save of classdef objects
* {{bug|60729}} print_usage within classdef constructor breaks subsequent calls to the class
* {{bug|61676}} Assigning classdef objects to other types does not call converter methods
* {{bug|63841}} nargout is always 1 for classdef methods


* '''Function handles to package methods and static class methods.'''
==== Classdef and +package directories ====
For example if we have <code>+mypackage/myfunc.m</code>, creating a function handle as <code>fh = @mypackage.myfunc</code> won't work.
As a workaround, we can create an indirection using an anonymous function <code>fh = @(varargin) mypackage.myfunc(varargin{:})</code>.
Similarly for static class methods where <code>fh = @MyClass.myfunc</code> isn't yet supported. Another workaround for package function handles is to use <code>str2func</code>, e.g. <code>fh = str2func ("mypackage.myfunc")</code>.


A fuller example is also given below:
* [https://savannah.gnu.org/bugs/?54941 54941] interpreter cannot find methods in files of classdefs in packages
<source lang="octave">
classdef method_function_handle_test


%  properties
==== Arrays of classdef objects ====
% 
% 
%  end
 
  properties (Hidden, SetAccess = protected)
    hfoo = [];% handle to function
  end
 
  methods
 
    function self = method_function_handle_test ()
      self.hfoo = @foo;   
    end
   
    function bar (self)
        self.hfoo (self);
    end


  end
* {{bug|44665}} error in concatenation of classdef objects
 
* {{bug|53906}} Cannot make an object array with square brackets
  methods (Hidden, Access = protected)
* {{bug|47755}} Access to object arrays
    function foo (self)
* {{bug|47241}} classdef: assigning property of handle object in object array constructs new object
      disp ('hello!');
    end
  end


end
==== Debugger (fixes for these are in progress) ====
</source>
Then running:
<source lang="text">
>> x = method_function_handle_test
error: @foo: no function and no method found
error: called from
    method_function_handle_test at line 17 column 17
stopped in <****>/scratch/mfiles/octave_tests/method_function_handle_test.m at line 17
17:      self.hfoo = @foo;
</source>


* {{bug|46451}} <s>unable to set breakpoints within classdef classes</s> - <em> Patch closed </em>
* {{bug|45404}} <s>Breakpoints cannot be set in classdef methods or +package function files</s> - <em>Report closed</em>
* {{bug|65610}} unable to set breakpoints within set or get functions of classdef classes - <em> Patch submitted </em>


* '''Defining [http://www.mathworks.com/help/matlab/matlab_oop/specifying-methods-and-functions.html#br2la89 local functions] in the same classdef-file is not working.'''
==== Lower-priority issues ====
For example, the following code gives a syntax/parse error:
<source lang="octave">
classdef MyClass
    methods
        function obj = MyClass()
            myfunc()
        end
    end
end


function myfunc()
* {{bug|55488}} Invalid use of colon char as classdef function's argument when subsref is overwritten
    disp('myfunc')
* {{bug|54966}} Error when assigning array to an object implementing subsasgn() subscripted using "{}"
end
* {{bug|54028}} copy of non-handle class instance is not deep
</source>
* {{bug|53811}} cellfun does not find overloaded function with function name argument
* {{bug|52989}} classdef: missing error messages on multiply defined properties
* {{bug|52582}} Dependent constant properties in classdef errors: no such file
* {{bug|52123}} Indirect memory leak in cdef_manager::initialize ()
* {{bug|51285}} max_recursion_depth error in classdef constructor
* {{bug|50395}} subclassing a class that is also defined as a variable fails
* {{bug|50011}} failure to report error on conflicting methods for classdef
* {{bug|49379}} classdef constructor: .argn. loses first argument, inputname(n) returns inputname(n+1)
* {{bug|55810}} sizeof() and whos() returns 0 bytes for classdef objects
* {{bug|45893}} classdef properties are not reloaded when file is updated
* {{bug|44643}} classdef handle object can go into an recursive loop with isequal(obj1,obj2) if both are self-referential
* {{bug|55755}} mxGetProperty does not work with properties marked as Dependent
* {{bug|55767}} classdef property should not be the same as classdef name (at least for Matlab compatibility)
* {{bug|44035}} unable to subclass built-in types
* {{bug|62432}} classdef object display of boolean matrix property fails with error message


See {{bug|41723}}.
==== Documentation ====


* '''debugging in classdef methods (and +package directory functions)'''
* {{bug|50729}} Improve OOP documentation
* {{bug|47908}} Octave:classdef-to-struct not documented in warning_ids.m
* {{bug|44590}} More documentation for the current status of classdef implementation


Breakpoints cannot currently be set in classdef methods from the gui, but only from the command line:
=== Classdef examples in Octave ===
<source lang="octave">
dbstop @aclass\amethod
</source>


* '''Saving/reading classdef objects to/from (.mat) file'''
* [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/miscellaneous/inputParser.m inputParser.m]
* [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/web/weboptions.m weboptions.m]
* [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/%2Bcontainers/Map.m +containers/Map.m]


=== Supported ===
[[Category:Development]]
 
* methods
** static
** private
 
* properties
** SetAccess (public/private/protected)
 
==== Classdef examples in the wild ====
 
* http://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/general/inputParser.m
* https://github.com/markuman/go-redis
* https://github.com/PetrKryslUCSD/FinEALE

Revision as of 12:13, 24 April 2024

Supported Features

Properties

Classdef properties are supported but not all attributes are implemented.

Attribute Support Notes
AbortSet No Property does not exist.
Abstract Yes
Access Partial
Constant Yes
Dependent Partial
GetAccess Partial
GetObservable No Property exists but is not used. Requires events and listeners to be implemented in order to work properly.
Hidden Yes
NonCopyable No Property does not exist.
SetAccess Partial
SetObservable No Property exists but is not used. Requires events and listeners to be implemented in order to work properly.
Transient No Property exists but is not used.

Methods

Classdef methods are supported but not all attributes are fully implemented.

Attribute Support Notes
Abstract Partial See bug report #51377
Access Yes
Hidden Yes
Sealed Yes
Static Yes

Features that are not implemented

enumeration

  • #44582 Parse the enumeration section of a classdef definition but nothing is done with it.

events and listeners

  • #56194 Parse the events section of a classdef definition but nothing is done with it.

Property Validation Functions

Open Bug Reports for Other Issues

Issues with basic classdef functionality

  • #51659 Calling 'methods' on self causes syntax error
  • #48682 print_usage fails within classdef block
  • #48041 classdef: `help myclass` messes up `help @myclass/method`
  • #52096 meta.class.fromName throws error when class name not found.
  • #48693 classdef subsref method is not called with correct nargout value - Patch applied, Ready for Test
  • #56006 Object indexing: obj(1).property(end+1:n) - end is interpreted wrong
  • #55983 'x(ix) = []' deletion syntax does not work for objects
  • #55976 cat, repmat, and reshape don't work for classdef objects
  • #55961 properties function does not preserve order - Patch submitted, awaiting review
  • #52582 using static method to initialize property value fails
  • #45833 support load/save of classdef objects
  • #60729 print_usage within classdef constructor breaks subsequent calls to the class
  • #61676 Assigning classdef objects to other types does not call converter methods
  • #63841 nargout is always 1 for classdef methods

Classdef and +package directories

  • 54941 interpreter cannot find methods in files of classdefs in packages

Arrays of classdef objects

  • #44665 error in concatenation of classdef objects
  • #53906 Cannot make an object array with square brackets
  • #47755 Access to object arrays
  • #47241 classdef: assigning property of handle object in object array constructs new object

Debugger (fixes for these are in progress)

  • #46451 unable to set breakpoints within classdef classes - Patch closed
  • #45404 Breakpoints cannot be set in classdef methods or +package function files - Report closed
  • #65610 unable to set breakpoints within set or get functions of classdef classes - Patch submitted

Lower-priority issues

  • #55488 Invalid use of colon char as classdef function's argument when subsref is overwritten
  • #54966 Error when assigning array to an object implementing subsasgn() subscripted using "{}"
  • #54028 copy of non-handle class instance is not deep
  • #53811 cellfun does not find overloaded function with function name argument
  • #52989 classdef: missing error messages on multiply defined properties
  • #52582 Dependent constant properties in classdef errors: no such file
  • #52123 Indirect memory leak in cdef_manager::initialize ()
  • #51285 max_recursion_depth error in classdef constructor
  • #50395 subclassing a class that is also defined as a variable fails
  • #50011 failure to report error on conflicting methods for classdef
  • #49379 classdef constructor: .argn. loses first argument, inputname(n) returns inputname(n+1)
  • #55810 sizeof() and whos() returns 0 bytes for classdef objects
  • #45893 classdef properties are not reloaded when file is updated
  • #44643 classdef handle object can go into an recursive loop with isequal(obj1,obj2) if both are self-referential
  • #55755 mxGetProperty does not work with properties marked as Dependent
  • #55767 classdef property should not be the same as classdef name (at least for Matlab compatibility)
  • #44035 unable to subclass built-in types
  • #62432 classdef object display of boolean matrix property fails with error message

Documentation

  • #50729 Improve OOP documentation
  • #47908 Octave:classdef-to-struct not documented in warning_ids.m
  • #44590 More documentation for the current status of classdef implementation

Classdef examples in Octave

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