PHP实现简单的模板引擎功能示例

<?php
namespace foo\base;
use foo\base\Object;
use foo\base\Compiler;
/**
* 
*/
class Template extends Object
{
 private $_config = [
  'suffix' => '.php',//文件后缀名
  'templateDir' => '../views/',//模板所在文件夹
  'pileDir' => '../runtime/cache/views/',//编译后存放的目录
  'suffixCompile' => '.php',//编译后文件后缀
  'isReCacheHtml' => false,//是否需要重新编译成静态html文件
  'isSupportPhp' => true,//是否支持php的语法
  'cacheTime' => 0,//缓存时间,单位秒
 ];
 private $_file;//带编译模板文件
 private $_valueMap = [];//键值对
 private $_piler;//编译器
 public function __construct($piler, $config = [])
 {
  $this->_piler = $piler;
  $this->_config = array_merge($this->_config, $config);
 }
 /**
  * [assign 存储控制器分配的键值]
  * @param [type] $values [键值对集合]
  * @return [type]   [description]
  */
 public function assign($values)
 {
  if (is_array($values)) {
   $this->_valueMap = $values;
  } else {
   throw new \Exception('控制器分配给视图的值必须为数组!');
  }
  return $this;
 }
 /**
  * [show 展现视图]
  * @param [type] $file [带编译缓存的文件]
  * @return [type]  [description]
  */
 public function show($file)
 {
  $this->_file = $file;
  if (!is_file($this->path())) {
   throw new \Exception('模板文件'. $file . '不存在!');
  }
  $pileFile = $this->_config['pileDir'] . md5($file) . $this->_config['suffixCompile'];
  $cacheFile = $this->_config['pileDir'] . md5($file) . '.html';
  //编译后文件不存在或者缓存时间已到期,重新编译,重新生成html静态缓存
  if (!is_file($pileFile) || $this->isRepile($pileFile)) {
   $this->_piler->pile($this->path(), $pileFile, $this->_valueMap);
   $this->_config['isReCacheHtml'] = true;
   if ($this->isSupportPhp()) {
    extract($this->_valueMap, EXTR_OVERWRITE);//从数组中将变量导入到当前的符号表
   }
  }
  if ($this->isReCacheHtml()) {
   ob_start();
   ob_clean();
   include($pileFile);
   file_put_contents($cacheFile, ob_get_contents());
   ob_end_flush();
  } else {
   readfile($cacheFile);
  }
 }
 /**
  * [isRepile 根据缓存时间判断是否需要重新编译]
  * @param [type] $pileFile [编译后的文件]
  * @return boolean    [description]
  */
 private function isRepile($pileFile)
 {
  return time() - filemtime($pileFile) > $this->_config['cacheTime'];
 }
 /**
  * [isReCacheHtml 是否需要重新缓存静态html文件]
  * @return boolean [description]
  */
 private function isReCacheHtml()
 {
  return $this->_config['isReCacheHtml'];
 }
 /**
  * [isSupportPhp 是否支持php语法]
  * @return boolean [description]
  */
 private function isSupportPhp()
 {
  return $this->_config['isSupportPhp'];
 }
 /**
  * [path 获得模板文件路径]
  * @return [type] [description]
  */
 private function path()
 {
  return $this->_config['templateDir'] . $this->_file . $this->_config['suffix'];
 }
}

<?php
namespace foo\base;
use foo\base\Object;
/**
* 
*/
class Compiler extends Object
{
 private $_content;
 private $_valueMap = [];
 private $_patten = [
  '#\{\\$([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)\}#',
  '#\{if (.*?)\}#',
  '#\{(else if|elseif) (.*?)\}#',
  '#\{else\}#',
  '#\{foreach \\$([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)}#',
  '#\{\/(foreach|if)}#',
  '#\{\\^(k|v)\}#',
 ];
 private $_translation = [
  "<?php echo \$this->_valueMap['\\1']; ?>",
  '<?php if (\\1) {?>',
  '<?php } else if (\\2) {?>',
  '<?php }else {?>',
  "<?php foreach (\$this->_valueMap['\\1'] as \$k => \$v) {?>",
  '<?php }?>',
  '<?php echo \$\\1?>'
 ];
 /**
  * [pile 编译模板文件]
  * @param [type] $source [模板文件]
  * @param [type] $destFile [编译后文件]
  * @param [type] $values [键值对]
  * @return [type]   [description]
  */
 public function pile($source, $destFile, $values)
 {
  $this->_content = file_get_contents($source);
  $this->_valueMap = $values;
  if (strpos($this->_content, '{$') !== false) {
   $this->_content = preg_replace($this->_patten, $this->_translation, $this->_content);
  }
  file_put_contents($destFile, $this->_content);
 }
}

/**
* [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->piler = 'foo\base\Compiler';
   $piler = $di->piler;
   return new \foo\base\Template($piler, $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;
}

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>Document</title>
</head>
<body>
 <p>展示模板文件视图</p> 
 <p>{$name}</p>
 <p>{$age}</p>
 <?php echo ++$age;?>
 {if $age > 18}
  <p>已成年</p>
 {else if $age < 10}
  <p>小毛孩</p>
 {/if}
 {foreach $friends} 
  <p>{^v} </p>
 {/foreach}
</body>
</html>