%ADD_GROUPS add groups or open them if they exist

%*-----------------------------------------------------------------------*
%|                                                                       |
%|  Except where otherwise noted, this work is licensed under a          |
%|  Creative Commons Attribution-NonCommercial-ShareAlike 4.0            |
%|  International (CC BY-NC-SA 4.0) license.                             |
%|                                                                       |
%|  Copyright (c) 2017 by Paul Scherrer Institute (http://www.psi.ch)    |
%|                                                                       |
%|       Author: CXS group, PSI                                          |
%*-----------------------------------------------------------------------*
% You may use this code with the following provisions:
%
% If the code is fully or partially redistributed, or rewritten in another
%   computing language this notice should be included in the redistribution.
%
% If this code, or subfunctions or parts of it, is used for research in a 
%   publication or if it is fully or partially rewritten for another 
%   computing language the authors and institution should be acknowledged 
%   in written form in the publication: “Data processing was carried out 
%   using the “cSAXS matlab package” developed by the CXS group,
%   Paul Scherrer Institut, Switzerland.” 
%   Variations on the latter text can be incorporated upon discussion with 
%   the CXS group if needed to more specifically reflect the use of the package 
%   for the published work.
%
% A publication that focuses on describing features, or parameters, that
%    are already existing in the code should be first discussed with the
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%   
% This code and subroutines are part of a continuous development, they 
%    are provided “as they are” without guarantees or liability on part
%    of PSI or the authors. It is the user responsibility to ensure its 
%    proper use and the correctness of the results.

function gid = add_groups(fileID, gpath, plist, varargin)

if nargin > 3
    single_data = varargin{1};
else
    single_data = true;
end

if ~single_data
    gpath_depth = length(gpath);
    gid{1} = fileID;
    for ii=1:gpath_depth
        try
            gid{end+1} = H5G.open(gid{ii}, gpath{ii}, plist);
        catch
            gid{end+1} = H5G.create(gid{ii},gpath{ii},plist,plist,plist);
        end
    end
    
else
    try
        gid = H5G.open(fileID, gpath, plist);
    catch
        gid = H5G.create(fileID,gpath,plist,plist,plist);
    end
end

end