Hi,
I think jqggrid wants a rather flat json file – see grid.base.js (around line 800): drows = data[ts.p.jsonReader.root]; – to me it looks like toplevel. So as I said, I think you should write a wrapper (wrapper.php):
<?php
$a = json_decode(file_get_contents($_GET[“filename”]),true);
echo json_encode(array(”items”=>$a[“GSP”][“RES”][“R”][0][“MT”]));
?>
and call it within your jqgrid (some parameters modified):
url:'wrapper.php?filename=http://somesite.com/wiredjsonfile.json',
colModel :[