changing the way object are displayed (overloading openvar)

Hi,

I've implemented a class in which I overloaded many basic function likes size, subsref, etc.

The problem is that when I open the class in the variable panel it calls my size and subsref functions which are slow. I want it to return a massage like can't display an object of size > 10.

I tried to create a m file overload.m and to override the builtin openvar function so when called with my object it would behave as desired, otherwise it would call the builtin function. It didn't work, not sure why.

function openvar(varname)
if isa(varnmae, 'MultiField')
    disp("can't display object");
else
    builtin('openvar', varname);
end
end

And when I try to open any variable I get

Error using openvar
Too many input arguments.

[Yong-Joo Kwon]

function openvar(varname, varargin)

if strcmp(varnmae, 'MultiField')

disp("can't display object");

else

evalin('caller', ['openvar ' varname]);

end

end

[Walter Roberson]

openvar receives a variable name, and the poster wants to check whether the variable named is of specific type, not whether the variable itself has specific name.

evalin caller is going to resolve to the exact same openvar routine, since the user was operating in the context of the calling routine when they got to this function.