I had to code with an old latin2 encoded portal system.
I got json_encode() Invalid UTF-8 sequence in argument Array …. warning.

The json_encode() function did this warning.

I changed to my own json_encode() function.

This source helped me: https://gist.github.com/jorgeatorres/1239453

function local_json_encode($a=false)
{
if (is_null($a)) return 'null';
if ($a === false) return 'false';
if ($a === true) return 'true';
if (is_scalar($a))
{
if (is_float($a))
{
// Always use "." for floats.
return floatval(str_replace(",", ".", strval($a)));
}
if (is_string($a))
{
static $jsonReplaces = array(array("\\", "/", "\n", "\t", "\r", "\b", "\f", '"'), array('\\\\', '\\/', '\\n', '\\t', '\\r', '\\b', '\\f', '\"'));
return '"' . str_replace($jsonReplaces[0], $jsonReplaces[1], $a) . '"';
}
else
return $a;
}
$isList = true;
for ($i = 0, reset($a); $i < count($a); $i++, next($a)) { if (key($a) !== $i) { $isList = false; break; } } $result = array(); if ($isList) { foreach ($a as $v) $result[] = local_json_encode($v); return '[' . join(',', $result) . ']'; } else { foreach ($a as $k => $v) $result[] = local_json_encode($k).':'.local_json_encode($v);
return '{' . join(',', $result) . '}';
}
}