<?php

namespace Illuminate\View\Compilers;

use Illuminate\Filesystem\Filesystem;

abstract class Compiler

{// a abstract class

    /**

     * The Filesystem instance.

     *

     * @var \Illuminate\Filesystem\Filesystem

     */

    protected $files;//The filesystem instance.

    /**

     * Get the cache path for the compiled views.

     *

     * @var string

     */

    protected $cachePath;//Get the cache path for the compiled views.

    /**

     * Create a new compiler instance.

     *

     * @param  \Illuminate\Filesystem\Filesystem  $files

     * @param  string  $cachePath

     * @return void

     */

    public function __construct(Filesystem $files, $cachePath)

    {

        $this->files = $files;

        $this->cachePath = $cachePath;

    }//_construct

   // files

   // set some construct

    /**

     * Get the path to the compiled version of a view.

     *

     * @param  string  $path

     * @return string

     */

    public function getCompiledPath($path)

    {

        return $this->cachePath.'/'.sha1($path).'.php';

    }// get The Compiled Path

    /**

     * Determine if the view at the given path is expired.

     *

     * @param  string  $path

     * @return bool

     */

    public function isExpired($path)

    {// check is expired

        $compiled = $this->getCompiledPath($path);// compiled

        // If the compiled file doesn't exist we will indicate that the view is expired

        // so that it can be re-compiled. Else, we will verify the last modification

        // of the views is less than the modification times of the compiled views.

        if (! $this->cachePath || ! $this->files->exists($compiled)) {

            return true;

        }// true

        $lastModified = $this->files->lastModified($path);

// last Modified

        return $lastModified >= $this->files->lastModified($compiled);

    }// has this result

}