Question

I have a constructor like this:

function p = class_name(folder, file_name)

    xmlfile = fullfile(folder, file_name);
    xDoc = xmlread(xmlfile);

        struct = xml2struct(xDoc);

        %lots of repetitive code

end

It reads and XML file and transforms it into a struct. The struct elements are then assign to the class’s properties/fields using some repetitive code like this:

if(isfield(struct.parameters, 'parameter_name'))
    p.property_name = struct.parameters.parameter_name.Text;
else
    p.property_name = '';
end

I would like to put this into a method/function which, given the name of the struct element (here ‘parameter_name’) and the name of the class field/property (here ‘property_name’) assigns the former to the latter.

Is it possible to write a generic function/method for this? Thanks.

Answer 1

You can implement such a function using dynamic field names. This is the recommended implementation for such cases:

function p = setparam(s, p, param_name, prop_name)
    if(isfield(s.parameters, param_name))
       param = s.parameters.(param_name);
       p.(prop_name) = param.Text;
    else
       p.(prop_name) = '';
    end
end

You can also use setfield and getfield on older versions of MATLAB:

function p = setparam(s, p, param_name, prop_name)
    if(isfield(s.parameters, param_name))
        param = getfield(s.parameters, param_name);
        p = setfield(p, prop_name, getfield(param, 'Text'));
    else
        p = setfield(p, prop_name, '');
    end
end

Do not use struct for structure name in your code – it is a reserved keyword.