Simple multi-language features with PHP. This feature will let user change the language of a page based on their preference,

readme.md

This is just an example on how to implement this feature to a page, for this purpose i implemented this feature to my registration page.

Requirement: 1. Target files 2. Language files

es.php, en.php, my.php -> is a language files, it contained translated description for my registration page registration.php -> is where the translation functionality will be use. PHP script will invoked the language files, based on the user languages preferences.

en.php

<?php 
  // English (Default) translation for registration page

	const _REGISTER = "Register";
	const _USERNAME = "Enter your username";
	const _EMAIL = "Enter your email";
	const _PASSWORD = "Enter your password";
	
 ?>

es.php

<?php 
  // Spanish translation for registration page

	const _REGISTER = "Registrate";
	const _USERNAME = "Nombre de Usuario";
	const _EMAIL = "Tu Correo";
	const _PASSWORD = "Tu Clave";

 ?>

my.php

<?php 
  // Malay translation for registration page

	const _REGISTER = "Daftar Akaun";
	const _USERNAME = "Masukkan Nama Anda";
	const _EMAIL = "Masukkan Email Anda";
	const _PASSWORD = "Masukkan Katalaluan anda";

 ?>

registration.php

<?php 
// ----------------------------------------------------------//
//  SCRIPT THAT WILL BE EXECUTING THE TRANSLATION  FUNCTION  //
// ----------------------------------------------------------//

// SETTING LANGUAGE VARIABLE
if(isset($_GET['lang']) && !empty($_GET['lang']))
{
    $_SESSION['lang'] = $_GET['lang'];

    // WILL RELOAD THE PAGE IF THE SELECTION IS CHANGE
    if(isset($_SESSION['lang']) && $_SESSION['lang'] != $_GET['lang']){
        echo "<script type='text/javascript'>location.reload();</script>";
    }
}

// IF THE SESSION SET IT WILL BE INCLUDING LANGUAGE BASED ON THE USER SELECTION
if(isset($_SESSION['lang'])){
    include "includes/languages/" . $_SESSION['lang'] . ".php";
 } else {
    include "includes/languages/en.php";
 }
?>

<!-- SELECTION TAG FOR CHOOSING LANGUAGE -->
<div class="container">
<!-- // THIS IS WHERE USER MAKE THE SELECTION, BY USING ONCHANGE EVENT-HANDLER IT WILL THEN PROCEED
     // SUBMITTING THE FORM THRU JS SCRIPT (BELOW), BY USING SUBMIT() FUNCTION, AFTER IT HAVE DETECTED
     // THE CHANGE (SELECTED) IN THE OPTION TAG. -->
  
<form method="get" class="navbar-form navbar-right "  id="language_form" k>
    <div class="form-group">
        <select name="lang" class="form-control" onchange="changeLanguage()">
            <option value="en" <?php if(isset($_SESSION['lang']) && $_SESSION['lang'] == 'en'){ echo "selected"; } ?>>English</option>
            <option value="es" <?php if(isset($_SESSION['lang']) && $_SESSION['lang'] == 'es'){ echo "selected"; } ?>>Spanish</option>
            <option value="my" <?php if(isset($_SESSION['lang']) && $_SESSION['lang'] == 'my'){ echo "selected"; } ?>>Malay</option>
        </select>
    </div>
</form>    

<!-- REGISTRATION FORM START -->
<!-- IT'S REQUIRE TO CHANGE THE PLACEHOLDER IN THE INPUT VALUE, JUST LIKE THE EXAMPLE BELOW. -->
<section id="login">
    <div class="container">
        <div class="row">
            <div class="col-xs-6 col-xs-offset-3">
                <div class="form-wrap">
                <h1><?php echo _REGISTER; ?></h1>
                    <form role="form" action="registration.php" method="post" id="login-form" autocomplete="on">

                        <div class="form-group">
                            <label for="username" class="sr-only">username</label>
                          
                            <input type="text" name="username" id="username" class="form-control" placeholder="<?php echo _USERNAME; ?>" value="<?php echo isset($username) ? $username : ''; ?>">
                          
                        </div>
                         <div class="form-group">
                            <label for="email" class="sr-only">Email</label>
                            <input type="email" name="email" id="email" class="form-control" placeholder="<?php echo _EMAIL; ?>" value="<?php echo isset($email) ? $email : ''; ?>">
                            
                        </div>
                         <div class="form-group">
                            <label for="password" class="sr-only">Password</label>
                            <input type="password" name="password" id="key" class="form-control" placeholder="<?php echo _PASSWORD; ?>" >
                       

                        </div>
                
                        <input type="submit" name="register" id="btn-login" class="btn btn-primary btn-lg btn-block" value="<?php echo _REGISTER; ?>">
                    </form>
                 
                </div>
            </div> <!-- /.col-xs-12 -->
        </div> <!-- /.row -->
    </div> <!-- /.container -->
</section>

<hr>
<!-- REGISTRATION FORM END -->

  
  
<!-- SUBMITING FORM WITH JS - START -->  
<script>
    // IT WILL BE SUBMITING THE FORM (METHOD: GET) USING THE SUBMIT FUNCTIONALITY
    function changeLanguage(){
        document.getElementById('language_form').submit();
    }
</script>
<!-- SUBMITING FORM WITH JS - END -->