Анатолий

function readTextFile(file, callback) {
    var rawFile = new XMLHttpRequest();
    rawFile.overrideMimeType("application/json");
    rawFile.open("GET", file, true);
    rawFile.onreadystatechange = function() {
        if (rawFile.readyState === 4 && rawFile.status == "200") {
            callback(rawFile.responseText);
        }
    }
    rawFile.send(null);
}

//использование:
readTextFile("/Users/Documents/workspace/test.json", function(text){
    var data = JSON.parse(text);
    console.log(data);
});

$json_string='{"name":"admin","id":"34","id_to":"8"}';
$obj=json_decode($json_string);
echo $obj->name;