jsonopt.m

function val = jsonopt(key, default, varargin)
%
% val=jsonopt(key,default,optstruct)
%
% setting options based on a struct. The struct can be produced
% by varargin2struct from a list of 'param','value' pairs
%
% authors:Qianqian Fang (q.fang <at> neu.edu)
%
% input:
%      key: a string with which one look up a value from a struct
%      default: if the key does not exist, return default
%      optstruct: a struct where each sub-field is a key
%
% output:
%      val: if key exists, val=optstruct.key; otherwise val=default
%
% license:
%     BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details
%
% -- this function is part of JSONLab toolbox (http://neurojson.org/jsonlab)
%

if nargin <= 2
    val = default;
    return
end

opt = varargin{1};
if ~isstruct(opt)
    val = default;
    return
end

% Try lowercase key first (most common case)
key0 = lower(key);
if isfield(opt, key0)
    val = opt.(key0);
elseif ~strcmp(key, key0) && isfield(opt, key)
    val = opt.(key);
else
    val = default;
end