1 <?php

     2 

     3 /*

     4  * This file is part of the Symfony package.

     5  *

     6  * (c) Fabien Potencier <fabien@symfony.com>

     7  *

     8  * For the full copyright and license information, please view the LICENSE

     9  * file that was distributed with this source code.

    10  */

    11 

    12 namespace Symfony\Component\BrowserKit;

    13 

    14 /**

    15  * History.

    16  *

    17  * @author Fabien Potencier <fabien@symfony.com>

    18  */

    19 class History

    20 {

    21     protected $stack = array();

    22     protected $position = -1;

    23 

    24     /**

    25      * Constructor.

    26      */

    27     public function __construct()

    28     {

    29         $this->clear();

    30     }

    31 

    32     /**

    33      * Clears the history.

    34      */

    35     public function clear()

    36     {

    37         $this->stack = array();

    38         $this->position = -1;

    39     }

    40 

    41     /**

    42      * Adds a Request to the history.

    43      *

    44      * @param Request $request A Request instance

    45      */

    46     public function add(Request $request)

    47     {

    48         $this->stack = array_slice($this->stack, 0, $this->position + 1);

    49         $this->stack[] = clone $request;

    50         $this->position = count($this->stack) - 1;

    51     }

    52 

    53     /**

    54      * Returns true if the history is empty.

    55      *

    56      * @return Boolean true if the history is empty, false otherwise

    57      */

    58     public function isEmpty()

    59     {

    60         return count($this->stack) == 0;

    61     }

    62 

    63     /**

    64      * Goes back in the history.

    65      *

    66      * @return Request A Request instance

    67      *

    68      * @throws \LogicException if the stack is already on the first page

    69      */

    70     public function back()

    71     {

    72         if ($this->position < 1) {

    73             throw new \LogicException('You are already on the first page.');

    74         }

    75 

    76         return clone $this->stack[--$this->position];

    77     }

    78 

    79     /**

    80      * Goes forward in the history.

    81      *

    82      * @return Request A Request instance

    83      *

    84      * @throws \LogicException if the stack is already on the last page

    85      */

    86     public function forward()

    87     {

    88         if ($this->position > count($this->stack) - 2) {

    89             throw new \LogicException('You are already on the last page.');

    90         }

    91 

    92         return clone $this->stack[++$this->position];

    93     }

    94 

    95     /**

    96      * Returns the current element in the history.

    97      *

    98      * @return Request A Request instance

    99      *

   100      * @throws \LogicException if the stack is empty

   101      */

   102     public function current()

   103     {

   104         if (-1 == $this->position) {

   105             throw new \LogicException('The page history is empty.');

   106         }

   107 

   108         return clone $this->stack[$this->position];

   109     }

   110 }