Slim REST API with Local File Storage

api.php

<?php

set_include_path ('/home');
require 'vendor/autoload.php';
\Slim\Slim::registerAutoloader();

const DATALOC = "/home/data";
$allowed_objects = ['tests'];

$app = new \Slim\Slim();
$app->config('debug', true);

/**
 * CREATE
 */
$app->post('/:object', function ($object) use ($app) {
    $filepath = DATALOC."/$object";
    if(!file_exists($filepath)) mkdir($filepath);
    $nextfile =  $filepath."/".getNextFile($filepath);
    $data = $app->request->getBody();
    $result = file_put_contents($nextfile, $data);
    echo json_encode((bool) $result);
});

/**
 * RETRIEVE
 */
$app->get('/:object', function ($object) use ($app)  {
    $filepath = DATALOC."/$object";
    $files    = glob($filepath.'/*');
    $data     = [];
    foreach($files as $i => $file){
        $filedata = json_decode(file_get_contents($file));
        $filedata->id = (int) basename($file);
        $data[] = $filedata;
    }
    echo json_encode($data);
});

$app->get('/:object/:id', function ($object, $id) use ($app)  {
    $filepath = DATALOC."/$object/$id.json";
    $data = json_decode(file_get_contents($filepath));
    $data->id = (int) basename($id);
    echo json_encode($data);
});

/**
 * UPDATE
 */
$app->put('/:object/:id', function ($object, $id) use ($app) {
    $filepath = DATALOC."/$object";
    $file = $filepath."/{$id}.json";
    $data = $app->request->getBody();
    $result = file_put_contents($file, $data);
    echo json_encode((bool) $result);
});

/**
 * DELETE
 */
$app->delete('/:object/:id', function ($object, $id) use ($app) {
    $filepath = DATALOC."/$object";
    $file = $filepath."/{$id}.json";
    $result = unlink($file);
    echo json_encode((bool) $result);
});

$app->run();

function getNextFile($filepath){
    $files= glob($filepath.'/*');
    sort($files); // sort the files from lowest to highest, alphabetically
    $file  = array_pop($files); // return the last element of the array
    $fileid = (int) basename($file);
    $nextfileid = $fileid + 1;
    $nextfile = $nextfileid.".json";
    return $nextfile;
}