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      Using PHP classes to store configuration data

      In my last projects I’m using something I think is useful and it’s not a common practice in our PHP projects. That’s is the usage of a plain PHP’s class for the application’s configuration. Let me explain it. Normally we use ini file for configuration. PHP has a built-in function for parse ini file. It converts the ini file into a PHP array

      ; our conf.ini file
      DEF_APP = home
      DEF_BCK = main
      DEF_FCT = index
      AUTH_ADAPTER = Nov\Auth\Def
       
      [PG1]
      driver = pgsql
      dsn = "pgsql:dbname=pg1;host=localhost"
      username = nov
      password = nov
      

      And now we use our ini file:

      $conf = parse_ini_file("conf.ini", true);
      print_r($conf);
      

      Another typical configuration file is xml. We also can use built-in functions within PHP when we want to parse xml files. There are also projects that use plain php files, and even yaml files (especially Symfony users)

      There are many standard options. Why I prefer a different one then? I like plain PHP classes because the IDE helps me with autocompletion. The usage is quite simple. Instead of using parse_ini_file function we only need to include our configuration class within our project.

      class Conf
      {
       const DEF_APP = 'index';
       const DEF_BCK = 'Index\Bck\Main\Page';
       const DEF_FCT = 'init';
       const AUTH_ADAPTER = "Nov\Auth\Def";
       
       const DB_PG1 = 'PG1';
       const DB_PG1_DRIVER   = 'pgsql';
       const DB_PG1_DSN      = 'pgsql:dbname=pg1;host=localhost';
       const DB_PG1_USERNAME = 'nov';
       const DB_PG1_PASSWORD = 'nov';
      }
      

      Sometimes I want to use a variable stored into the application’s configuration but I don’t remember exactly the name of the variable. If I’ve got the configuration stored into a PHP array from a ini file (or xml, yaml, … ). I need to open the configuration file and find the name of the variable to use in my code. With a PHP class IDEs like Netbeans of VIM will pop up an autocompletion hint with the name of the variable

      An example of coding autocompletion with Netbeans

      The same with VIM

      And that’s all. Maybe the worse part of this technique is if our application writes the configuration file (a typical installer.php). In this case we need to build the PHP’s class file and it’s slightly more complicated than writing a simple ini file.

      What do you think about it? Do you use another different way?

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