Fix character encoding for special characters in JSON output

[sretenD]

The application is producing undecoded characters like šđćž due to an encoding error during JSON or HTML writing. The m2json.m file needs to be modified to ensure proper UTF-8 encoding before escaping special characters. The suggested solution is to add the unicode2native(val, 'UTF-8') function before line 43 in m2json.m.

41|          else
42|              val = unicode2native(val, 'UTF-8'); % Convert to UTF-8
43|              val = checkescape(val); % add escape characters
44|              valstr = sprintf(\"\"\"%s\"\"\", val);

[robertoffmoura]

Hi! Thanks for raising this issue. Could you please share an example of the encoding error you're seeing?

[sretenD]

I have resolved the issue. I used this function and call it
% plotly_aux/htmlencode.m
function encoded = htmlencode(str)
% Converts special characters to HTML entities
encoded = str;
% Basic HTML entities
encoded = strrep(encoded, '&', '&');
encoded = strrep(encoded, '<', '<');
encoded = strrep(encoded, '>', '>');
encoded = strrep(encoded, '"', '"');
encoded = strrep(encoded, '''', ''');
% Unicode handling: convert non-ASCII to &#xXXXX;
encoded = regexprep(encoded, '[^\x00-\x7F]', ...
'${sprintf(''&#x%04X;'', double($0))}');
end

so in m2jason.m
val = checkescape(val); % add escape characters
noTags = regexprep(val, '<[^>]+>', '');
val = htmlencode(noTags); % NEW: encode special/unicode chars
valstr = sprintf("""%s""", val);

in plotlyoffline.m
% handle plot div specs
noTags = regexprep(char(java.util.UUID.randomUUID), '<[^>]+>', '');
id = htmlencode(noTags);

    noTags = regexprep(linkText, '<[^>]+>', '');
    linkText = htmlencode(noTags);

so I cleared the issue.