PHP实现简单的模板引擎功能示例

/**
* [render 渲染模板文件]
* @param [type] $file      [待编译的文件]
* @param [type] $values     [键值对]
* @param array $templateConfig [编译配置]
* @return [type]         [description]
*/
protected function render($file, $values, $templateConfig = [])
{
    $di = Container::getInstance();
    //依赖注入实例化对象
    $di->template = function () use ($di, $templateConfig) {
      $di->compiler = 'foo\base\Compiler';
      $compiler = $di->compiler;
      return new \foo\base\Template($compiler, $templateConfig);
    };
    $di->template->assign($values)->show($file);
}

<?php
namespace foo\base;
use foo\base\Object;
class Container extends Object
{
  private static $_instance;
  private $s = [];
  public static $instances = [];
  public static function getInstance()
  {
    if (!(self::$_instance instanceof self)) {
      self::$_instance = new self();
    }
    return self::$_instance;
  }
  private function __construct(){}
  private function __clone(){}
  public function __set($k, $c)
  {
    $this->s[$k] = $c;
  }
  public function __get($k)
  {
    return $this->build($this->s[$k]);
  }
  /**
   * 自动绑定（Autowiring）自动解析（Automatic Resolution）
   *
   * @param string $className
   * @return object
   * @throws Exception
   */
  public function build($className)
  {   
    // 如果是闭包函数（closures）
    if ($className instanceof \Closure) {
      // 执行闭包函数
      return $className($this);
    }
    if (isset(self::$instances[$className])) {
      return self::$instances[$className];
    }
    /** @var ReflectionClass $reflector */
    $reflector = new \ReflectionClass($className);
    // 检查类是否可实例化, 排除抽象类abstract和对象接口interface
    if (!$reflector->isInstantiable()) {
      throw new \Exception($reflector . ': 不能实例化该类!');
    }
    /** @var ReflectionMethod $constructor 获取类的构造函数 */
    $constructor = $reflector->getConstructor();
    // 若无构造函数，直接实例化并返回
    if (is_null($constructor)) {
      return new $className;
    }
    // 取构造函数参数,通过 ReflectionParameter 数组返回参数列表
    $parameters = $constructor->getParameters();
    // 递归解析构造函数的参数
    $dependencies = $this->getDependencies($parameters);
    // 创建一个类的新实例，给出的参数将传递到类的构造函数。
    $obj = $reflector->newInstanceArgs($dependencies);
    self::$instances[$className] = $obj;
    return $obj;
  }
  /**
   * @param array $parameters
   * @return array
   * @throws Exception
   */
  public function getDependencies($parameters)
  {
    $dependencies = [];
    /** @var ReflectionParameter $parameter */
    foreach ($parameters as $parameter) {
      /** @var ReflectionClass $dependency */
      $dependency = $parameter->getClass();
      if (is_null($dependency)) {
        // 是变量,有默认值则设置默认值
        $dependencies[] = $this->resolveNonClass($parameter);
      } else {
        // 是一个类，递归解析
        $dependencies[] = $this->build($dependency->name);
      }
    }
    return $dependencies;
  }
  /**
   * @param ReflectionParameter $parameter
   * @return mixed
   * @throws Exception
   */
  public function resolveNonClass($parameter)
  {
    // 有默认值则返回默认值
    if ($parameter->isDefaultValueAvailable()) {
      return $parameter->getDefaultValue();
    }
    throw new \Exception('I have no idea what to do here.');
  }
}

public function offsetExists($offset) 
{
    return array_key_exists($offset, get_object_vars($this));
}
public function offsetUnset($key) 
{
    if (array_key_exists($key, get_object_vars($this)) ) {
      unset($this->{$key});
    }
}
public function offsetSet($offset, $value) 
{
    $this->{$offset} = $value;
}
public function offsetGet($var) 
{
    return $this->$var;
}