Adminer plugin Jason pretty print based on json-column.php official plugin

adminer-plugin-json-pretty-print.php

<?php

/** Display JSON values as table in edit
* @link https://www.adminer.org/plugins/#use
* @author Jakub Vrana, https://www.vrana.cz/
* @author Martin Zeman (Zemistr), http://www.zemistr.eu/
* @license https://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
* @license https://www.gnu.org/licenses/gpl-2.0.html GNU General Public License, version 2 (one or other)
*/
class AdminerJsonColumn {
  private function _testJson($value) {
    if ((substr($value, 0, 1) == '{' || substr($value, 0, 1) == '[') && ($json = json_decode($value, true))) {
      return $json;
    }
    return $value;
  }

  function editInput($table, $field, $attrs, $value) {
    $json = $this->_testJson($value);
    if ($json !== $value) {
      echo '<pre>' . json_encode($json, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . '</pre>';
    }
  }
}