Editing Classdef

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

=== Not Supported ===

* '''enumeration'''

See {{bug|44582}} and help implementing it.


* '''build-in class as superclass'''
<source lang="octave">
classdef nonsense < uint32

end
</source>

See {{bug|44035}}

* '''[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].''' 

Example:
<source lang="octave">
classdef MyClass < handle
end

c = MyClass();
cc = [c, c];   % won't work
</source>

For now you can use a cell-array of objects instead:
<source lang="octave">
cc = {c, c};   % ok
</source>

Also see {{bug|44665}}

* '''[http://www.mathworks.com/help/matlab/matlab_oop/mutable-and-immutable-properties.html Immutable property] set access.'''
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.


* '''Function handles to package methods and static class methods.'''
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:
<source lang="octave">
classdef method_function_handle_test

%  properties
%  
%  
%  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
  
  methods (Hidden, Access = protected)
    function foo (self)
      disp ('hello!');
    end
  end

end
</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>

See {{bug|45351}}

* '''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.''' 
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()
    disp('myfunc')
end
</source>

See {{bug|41723}}.

* '''debugging in classdef methods (and +package directory functions)'''

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

See {{bug|45404}}

* '''Saving/reading classdef objects to/from (.mat) file'''

=== Supported ===

* methods
** static
** private

* properties
** SetAccess (public/private/protected)

=== Open Bug Reports ===

Issues with basic classdef functionality

* [https://savannah.gnu.org/bugs/?51659 51659] Calling 'methods' on self causes syntax error
* [https://savannah.gnu.org/bugs/?48682 48682] print_usage fails within classdef block
* [https://savannah.gnu.org/bugs/?49434 49434] which returns "built-in function" for classdef m-file
* [https://savannah.gnu.org/bugs/?48041 48041] classdef: `help myclass` messes up `help @myclass/method`
* [https://savannah.gnu.org/bugs/?43047 43047] help() does not see classdef files
* [https://savannah.gnu.org/bugs/?42620 42620] exist() does not use "class" argument
* [https://savannah.gnu.org/bugs/?53874 53874] doc_cache_create doesnt handle classdef documentation
* [https://savannah.gnu.org/bugs/?52096 52096] meta.class.fromName throws error when class name not found.
* [https://savannah.gnu.org/bugs/?51377 51377] Parse error for abstract methods
* [https://savannah.gnu.org/bugs/?44665 44665] error in concatenation of classdef objects
* [https://savannah.gnu.org/bugs/?44582 44582] classdef: missing support for enumeration
* [https://savannah.gnu.org/bugs/?48693 48693] classdef subsref method is not called with correct nargout value

Classdef and +package directories

* [https://savannah.gnu.org/bugs/?54941 54941] interpreter cannot find methods in files of classdefs in packages

Arrays of classdef objects

* [https://savannah.gnu.org/bugs/?53906 53906] Cannot make an object array with square brackets
* [https://savannah.gnu.org/bugs/?47755 47755] Access to object arrays
* [https://savannah.gnu.org/bugs/?47241 47241] classdef: assigning property of handle object in object array constructs new object

I/O issues

* [https://savannah.gnu.org/bugs/?45833 45833] support load/save of classdef objects

Debugger

* [https://savannah.gnu.org/bugs/?46451 46451] unable to set breakpoints within classdef classes
* [https://savannah.gnu.org/bugs/?45404 45404] Breakpoints cannot be set in classdef methods or +package function files

Lower-priority issues

* [https://savannah.gnu.org/bugs/?55488 55488] Invalid use of colon char as classdef function's argument when subsref is overwritten
* [https://savannah.gnu.org/bugs/?55487 55487] ismethod of custom classdefs always returning false
* [https://savannah.gnu.org/bugs/?54966 54966] Error when assigning array to an object implementing subsasgn() subscripted using "{}"
* [https://savannah.gnu.org/bugs/?54783 54783] subsasgn call when the subscripted expression contains the end keyword
* [https://savannah.gnu.org/bugs/?54028 54028] copy of non-handle class instance is not deep
* [https://savannah.gnu.org/bugs/?53811 53811] cellfun does not find overloaded function with function name argument
* [https://savannah.gnu.org/bugs/?52989 52989] classdef: missing error messages on multiply defined properties
* [https://savannah.gnu.org/bugs/?52614 52614] setting properties of classdef object during construction with inheritance
* [https://savannah.gnu.org/bugs/?52582 52582] Dependent constant properties in classdef errors: no such file
* [https://savannah.gnu.org/bugs/?52123 52123] Indirect memory leak in cdef_manager::initialize ()
* [https://savannah.gnu.org/bugs/?51285 51285] max_recursion_depth error in classdef constructor
* [https://savannah.gnu.org/bugs/?50395 50395] subclassing a class that is also defined as a variable fails
* [https://savannah.gnu.org/bugs/?50011 50011] failure to report error on conflicting methods for classdef
* [https://savannah.gnu.org/bugs/?49379 49379] classdef constructor: .argn. loses first argument, inputname(n) returns inputname(n+1)
* [https://savannah.gnu.org/bugs/?46652 46652] whos bytes property not right for classdef classes
* [https://savannah.gnu.org/bugs/?45893 45893] classdef properties are not reloaded when file is updated
* [https://savannah.gnu.org/bugs/?44934 44934] classdef parser prints extra newline when failing to parse bad classdef file
* [https://savannah.gnu.org/bugs/?44643 44643] classdef handle object can go into an recursive loop with isequal(obj1,obj2) if both are self-referential
* [https://savannah.gnu.org/bugs/?44035 44035] classdef is unable to to subclass double

Documentation

* [https://savannah.gnu.org/bugs/?50729 50729] Improve OOP documentation
* [https://savannah.gnu.org/bugs/?47908 47908] Octave:classdef-to-struct not documented in warning_ids.m
* [https://savannah.gnu.org/bugs/?44590 44590] More documentation for the current status of classdef implementation

=== Classdef examples in the wild ===

* http://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/general/inputParser.m
* http://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/%2Bcontainers/Map.m
* https://github.com/markuman/go-redis
* https://github.com/PetrKryslUCSD/FinEALE