Писал для своего фреймворка (ВЕЛОСИПЕДЫ РУЛЕЗ!!)

Позволяет вам обращаться к конфигурации приложения которая хранится в JSON формате

пример в конце кода, код прокомментирован

                        
<?php

namespace VendorApp;



interface JsonConfigInterface

{

    /*

        Returns an instance of itself

    */

    static function getInstance ();

    /*

        A parameter of type string

        

        The method parameter is the path to the configuration file

    */

    function setConfigPath ($path);

    /*

        A parameter of type string

        

        The default file which will be used in the case where the method getItem() is not passed to the second parameter

    */

    function setDefaultFile ($fileName);

    /*

        A parameter of type string

        A parameter of type string

        

        Reads the JSON file "$file".

        Converts from JSON to an array and looks for the key "$item" in case of success returns its value otherwise NULL

    */

    function getItem ($item, $file = '');

}



class JsonConfig implements JsonConfigInterface

{

    private $readData    = [];

    private $configPath  = '';

    private $defaultFile = 'config';

    private static $instance;

    

    static function getInstance ()

    {

        if (!is_object(self::$instance))

        {

            self::$instance = new self();

        }

        

        return self::$instance;

    }

    

    public function getItem ($item, $file = '')

    {

        if (empty($file))

        {

            $file = $this->defaultFile;

        }

        

        $fullPathFile = rtrim($this->configPath, '/').'/'.$file.'.json';

        

        if (!file_exists($fullPathFile))

        {

            throw new Exception('The configuration file is not found');

        }

        

        if (!isset($this->readData[$file]))

        {

            $jsonData = file_get_contents($fullPathFile);

            $jsonData = json_decode($jsonData, TRUE);

        

            switch (json_last_error()) 

            {

                case JSON_ERROR_DEPTH:

                    throw new Exception('You have reached the maximum stack depth');

                break;

                case JSON_ERROR_STATE_MISMATCH:

                    throw new Exception('Incorrect digits or the coincidence of modes');

                break;

                case JSON_ERROR_CTRL_CHAR:

                    throw new Exception('Invalid control character');

                break;

                case JSON_ERROR_SYNTAX:

                    throw new Exception('Syntax error, not a valid JSON');

                break;

                case JSON_ERROR_UTF8:

                    throw new Exception('Incorrect UTF-8 characters, possibly invalid encoding');

                break;

            }

            

            $this->readData[$file] = $jsonData;

        }

        

        return (isset($this->readData[$file][$item]) ? $this->readData[$file][$item] : NULL);

    }

    

    public function setDefaultFile ($fileName)

    {

        $this->defaultFile = $fileName;

    }

    

    public function setConfigPath ($path)

    {

        if (!is_dir($path))

        {

            throw new Exception('Path to configuration files is not correct');

        }

        

        $this->configPath = $path;

    }

    

    protected function __clone() { }

    protected function __construct() {}

}



/*

    Example use class:

    

    $jsonConfig = JsonConfig::getInstance();

    $jsonConfig->setConfigPath('/var/www/tcs.lo/www/');

    $jsonConfig->setDefaultFile('test');



    echo $jsonConfig->getItem('site-name');

    echo $jsonConfig->getItem('username', 'database');

*/