Scottchiefbaker/master (#1019)

* Add a PSR-4 loading script to allow Smarty to be used without Composer
authored-by: Scott Baker <scott@perturb.org>

changelog/1017.md

@@ -0,0 +1 @@
+- Added a PSR-4 loading script to allow Smarty to be used without Composer [#1017](https://github.com/smarty-php/smarty/pull/1017)

docs/getting-started.md

@@ -25,9 +25,17 @@ Here's how you create an instance of Smarty in your PHP scripts:
 ```php
 <?php
 
+// Instantiated via composer
 require 'vendor/autoload.php';
 use Smarty\Smarty;
 $smarty = new Smarty();
+
+// or ...
+
+// Instantiated directly
+require("/path/to/smarty/libs/Smarty.class.php");
+use Smarty\Smarty;
+$smarty = new Smarty();
 ```
 
 Now that the library files are in place, it's time to set up the Smarty

libs/Smarty.class.php

@@ -0,0 +1,42 @@
+<?php
+
+/////////////////////////////////////////////////////////////////////
+// This is a stub PSR-4 loading script that gets all the pieces of //
+// Smarty 5.x loaded without requiring the use of composer. It's   //
+// not really a 'class' file, but the name is used so we're        //
+// backwards compatible with previous versions of Smarty.          //
+//                                                                 //
+// Example:                                                        //
+// require_once("/path/to/smarty/libs/Smarty.class.php");          //
+//                                                                 //
+// $smarty = new Smarty\Smarty;                                    //
+// $smarty->testInstall();                                         //
+/////////////////////////////////////////////////////////////////////
+
+define('__SMARTY_DIR', __DIR__ . '/../src/');
+
+// Global function declarations
+require_once(__SMARTY_DIR . "/functions.php");
+
+spl_autoload_register(function ($class) {
+	// Class prefix
+	$prefix = 'Smarty\\';
+
+	// Does the class use the namespace prefix?
+	$len = strlen($prefix);
+	if (strncmp($prefix, $class, $len) !== 0) {
+		// If not, move to the next registered autoloader
+		return;
+	}
+
+	// Hack off the prefix part
+	$relative_class = substr($class, $len);
+
+	// Build a path to the include file
+	$file = __SMARTY_DIR . str_replace('\\', '/', $relative_class) . '.php';
+
+	// If the file exists, require it
+	if (file_exists($file)) {
+		require_once($file);
+	}
+});