How to compress and merge js in php

这篇文章主要介绍了php实现压缩合并js的方法,涉及php压缩文件类JSMin的相关调用与使用技巧,并附带了完整的demo源码供读者下载参考,需要的朋友可以参考下

test.php文件如下：

require_once('jsmin.php');
$files = glob("js/*.js");
$js = "";
foreach($files as $file) {
  $js .= JSMin::minify(file_get_contents($file));
}
file_put_contents("combined.js", $js);
echo "success";

jsmin.php文件如下：

<?php
/**
 * jsmin.php - PHP implementation of Douglas Crockford&#39;s JSMin.
 *
 * This is pretty much a direct port of jsmin.c to PHP with just a few
 * PHP-specific performance tweaks. Also, whereas jsmin.c reads from stdin and
 * outputs to stdout, this library accepts a string as input and returns another
 * string as output.
 *
 * PHP 5 or higher is required.
 *
 * Permission is hereby granted to use this version of the library under the
 * same terms as jsmin.c, which has the following license:
 *
 * --
 * Copyright (c) 2002 Douglas Crockford (www.crockford.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * The Software shall be used for Good, not Evil.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * --
 *
 * @package JSMin
 * @author Ryan Grove <ryan@wonko.com>
 * @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
 * @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
 * @copyright 2012 Adam Goforth <aag@adamgoforth.com> (Updates)
 * @license http://opensource.org/licenses/mit-license.php MIT License
 * @version 1.1.2 (2012-05-01)
 * @link https://github.com/rgrove/jsmin-php
 */
class JSMin {
 const ORD_LF      = 10;
 const ORD_SPACE     = 32;
 const ACTION_KEEP_A   = 1;
 const ACTION_DELETE_A  = 2;
 const ACTION_DELETE_A_B = 3;
 protected $a      = &#39;&#39;;
 protected $b      = &#39;&#39;;
 protected $input    = &#39;&#39;;
 protected $inputIndex = 0;
 protected $inputLength = 0;
 protected $lookAhead  = null;
 protected $output   = &#39;&#39;;
 // -- Public Static Methods --------------------------------------------------
 /**
  * Minify Javascript
  *
  * @uses __construct()
  * @uses min()
  * @param string $js Javascript to be minified
  * @return string
  */
 public static function minify($js) {
  $jsmin = new JSMin($js);
  return $jsmin->min();
 }
 // -- Public Instance Methods ------------------------------------------------
 /**
  * Constructor
  *
  * @param string $input Javascript to be minified
  */
 public function __construct($input) {
  $this->input    = str_replace("\r\n", "\n", $input);
  $this->inputLength = strlen($this->input);
 }
 // -- Protected Instance Methods ---------------------------------------------
 /**
  * Action -- do something! What to do is determined by the $command argument.
  *
  * action treats a string as a single character. Wow!
  * action recognizes a regular expression if it is preceded by ( or , or =.
  *
  * @uses next()
  * @uses get()
  * @throws JSMinException If parser errors are found:
  *     - Unterminated string literal
  *     - Unterminated regular expression set in regex literal
  *     - Unterminated regular expression literal
  * @param int $command One of class constants:
  *   ACTION_KEEP_A   Output A. Copy B to A. Get the next B.
  *   ACTION_DELETE_A  Copy B to A. Get the next B. (Delete A).
  *   ACTION_DELETE_A_B Get the next B. (Delete B).
 */
 protected function action($command) {
  switch($command) {
   case self::ACTION_KEEP_A:
    $this->output .= $this->a;
   case self::ACTION_DELETE_A:
    $this->a = $this->b;
    if ($this->a === "&#39;" || $this->a === &#39;"&#39;) {
     for (;;) {
      $this->output .= $this->a;
      $this->a    = $this->get();
      if ($this->a === $this->b) {
       break;
      }
      if (ord($this->a) <= self::ORD_LF) {
       throw new JSMinException(&#39;Unterminated string literal.&#39;);
      }
      if ($this->a === &#39;\\&#39;) {
       $this->output .= $this->a;
       $this->a    = $this->get();
      }
     }
    }
   case self::ACTION_DELETE_A_B:
    $this->b = $this->next();
    if ($this->b === &#39;/&#39; && (
      $this->a === &#39;(&#39; || $this->a === &#39;,&#39; || $this->a === &#39;=&#39; ||
      $this->a === &#39;:&#39; || $this->a === &#39;[&#39; || $this->a === &#39;!&#39; ||
      $this->a === &#39;&&#39; || $this->a === &#39;|&#39; || $this->a === &#39;?&#39; ||
      $this->a === &#39;{&#39; || $this->a === &#39;}&#39; || $this->a === &#39;;&#39; ||
      $this->a === "\n" )) {
     $this->output .= $this->a . $this->b;
     for (;;) {
      $this->a = $this->get();
      if ($this->a === &#39;[&#39;) {
       /*
        inside a regex [...] set, which MAY contain a &#39;/&#39; itself. Example: mootools Form.Validator near line 460:
         return Form.Validator.getValidator(&#39;IsEmpty&#39;).test(element) || (/^(?:[a-z0-9!#$%&&#39;*+/=?^_`{|}~-]\.?){0,63}[a-z0-9!#$%&&#39;*+/=?^_`{|}~-]@(?:(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)*[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\])$/i).test(element.get(&#39;value&#39;));
       */
       for (;;) {
        $this->output .= $this->a;
        $this->a = $this->get();
        if ($this->a === &#39;]&#39;) {
          break;
        } elseif ($this->a === &#39;\\&#39;) {
         $this->output .= $this->a;
         $this->a    = $this->get();
        } elseif (ord($this->a) <= self::ORD_LF) {
         throw new JSMinException(&#39;Unterminated regular expression set in regex literal.&#39;);
        }
       }
      } elseif ($this->a === &#39;/&#39;) {
       break;
      } elseif ($this->a === &#39;\\&#39;) {
       $this->output .= $this->a;
       $this->a    = $this->get();
      } elseif (ord($this->a) <= self::ORD_LF) {
       throw new JSMinException(&#39;Unterminated regular expression literal.&#39;);
      }
      $this->output .= $this->a;
     }
     $this->b = $this->next();
    }
  }
 }
 /**
  * Get next char. Convert ctrl char to space.
  *
  * @return string|null
  */
 protected function get() {
  $c = $this->lookAhead;
  $this->lookAhead = null;
  if ($c === null) {
   if ($this->inputIndex < $this->inputLength) {
    $c = substr($this->input, $this->inputIndex, 1);
    $this->inputIndex += 1;
   } else {
    $c = null;
   }
  }
  if ($c === "\r") {
   return "\n";
  }
  if ($c === null || $c === "\n" || ord($c) >= self::ORD_SPACE) {
   return $c;
  }
  return &#39; &#39;;
 }
 /**
  * Is $c a letter, digit, underscore, dollar sign, or non-ASCII character.
  *
  * @return bool
  */
 protected function isAlphaNum($c) {
  return ord($c) > 126 || $c === &#39;\\&#39; || preg_match(&#39;/^[\w\$]$/&#39;, $c) === 1;
 }
 /**
  * Perform minification, return result
  *
  * @uses action()
  * @uses isAlphaNum()
  * @uses get()
  * @uses peek()
  * @return string
  */
 protected function min() {
  if (0 == strncmp($this->peek(), "\xef", 1)) {
    $this->get();
    $this->get();
    $this->get();
  } 
  $this->a = "\n";
  $this->action(self::ACTION_DELETE_A_B);
  while ($this->a !== null) {
   switch ($this->a) {
    case &#39; &#39;:
     if ($this->isAlphaNum($this->b)) {
      $this->action(self::ACTION_KEEP_A);
     } else {
      $this->action(self::ACTION_DELETE_A);
     }
     break;
    case "\n":
     switch ($this->b) {
      case &#39;{&#39;:
      case &#39;[&#39;:
      case &#39;(&#39;:
      case &#39;+&#39;:
      case &#39;-&#39;:
      case &#39;!&#39;:
      case &#39;~&#39;:
       $this->action(self::ACTION_KEEP_A);
       break;
      case &#39; &#39;:
       $this->action(self::ACTION_DELETE_A_B);
       break;
      default:
       if ($this->isAlphaNum($this->b)) {
        $this->action(self::ACTION_KEEP_A);
       }
       else {
        $this->action(self::ACTION_DELETE_A);
       }
     }
     break;
    default:
     switch ($this->b) {
      case &#39; &#39;:
       if ($this->isAlphaNum($this->a)) {
        $this->action(self::ACTION_KEEP_A);
        break;
       }
       $this->action(self::ACTION_DELETE_A_B);
       break;
      case "\n":
       switch ($this->a) {
        case &#39;}&#39;:
        case &#39;]&#39;:
        case &#39;)&#39;:
        case &#39;+&#39;:
        case &#39;-&#39;:
        case &#39;"&#39;:
        case "&#39;":
         $this->action(self::ACTION_KEEP_A);
         break;
        default:
         if ($this->isAlphaNum($this->a)) {
          $this->action(self::ACTION_KEEP_A);
         }
         else {
          $this->action(self::ACTION_DELETE_A_B);
         }
       }
       break;
      default:
       $this->action(self::ACTION_KEEP_A);
       break;
     }
   }
  }
  return $this->output;
 }
 /**
  * Get the next character, skipping over comments. peek() is used to see
  * if a &#39;/&#39; is followed by a &#39;/&#39; or &#39;*&#39;.
  *
  * @uses get()
  * @uses peek()
  * @throws JSMinException On unterminated comment.
  * @return string
  */
 protected function next() {
  $c = $this->get();
  if ($c === &#39;/&#39;) {
   switch($this->peek()) {
    case &#39;/&#39;:
     for (;;) {
      $c = $this->get();
      if (ord($c) <= self::ORD_LF) {
       return $c;
      }
     }
    case &#39;*&#39;:
     $this->get();
     for (;;) {
      switch($this->get()) {
       case &#39;*&#39;:
        if ($this->peek() === &#39;/&#39;) {
         $this->get();
         return &#39; &#39;;
        }
        break;
       case null:
        throw new JSMinException(&#39;Unterminated comment.&#39;);
      }
     }
    default:
     return $c;
   }
  }
  return $c;
 }
 /**
  * Get next char. If is ctrl character, translate to a space or newline.
  *
  * @uses get()
  * @return string|null
  */
 protected function peek() {
  $this->lookAhead = $this->get();
  return $this->lookAhead;
 }
}
// -- Exceptions ---------------------------------------------------------------
class JSMinException extends Exception {}
?>

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