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\Console\Helper;

    13 

    14 use Symfony\Component\Console\Output\OutputInterface;

    15 

    16 /**

    17  * The Dialog class provides helpers to interact with the user.

    18  *

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

    20  */

    21 class DialogHelper extends Helper

    22 {

    23     private $inputStream;

    24 

    25     /**

    26      * Asks a question to the user.

    27      *

    28      * @param OutputInterface $output

    29      * @param string|array    $question The question to ask

    30      * @param string          $default  The default answer if none is given by the user

    31      *

    32      * @return string The user answer

    33      */

    34     public function ask(OutputInterface $output, $question, $default = null)

    35     {

    36         $output->write($question);

    37 

    38         $ret = fgets($this->inputStream ?: STDIN, 4096);

    39         if (false === $ret) {

    40             throw new \RuntimeException('Aborted');

    41         }

    42         $ret = trim($ret);

    43 

    44         return strlen($ret) > 0 ? $ret : $default;

    45     }

    46 

    47     /**

    48      * Asks a confirmation to the user.

    49      *

    50      * The question will be asked until the user answer by nothing, yes, or no.

    51      *

    52      * @param OutputInterface $output

    53      * @param string|array    $question The question to ask

    54      * @param Boolean         $default  The default answer if the user enters nothing

    55      *

    56      * @return Boolean true if the user has confirmed, false otherwise

    57      */

    58     public function askConfirmation(OutputInterface $output, $question, $default = true)

    59     {

    60         $answer = 'z';

    61         while ($answer && !in_array(strtolower($answer[0]), array('y', 'n'))) {

    62             $answer = $this->ask($output, $question);

    63         }

    64 

    65         if (false === $default) {

    66             return $answer && 'y' == strtolower($answer[0]);

    67         }

    68 

    69         return !$answer || 'y' == strtolower($answer[0]);

    70     }

    71 

    72     /**

    73      * Asks for a value and validates the response.

    74      *

    75      * The validator receives the data to validate. It must return the

    76      * validated data when the data is valid and throw an exception

    77      * otherwise.

    78      *

    79      * @param OutputInterface $output

    80      * @param string|array    $question

    81      * @param callback        $validator A PHP callback

    82      * @param integer         $attempts Max number of times to ask before giving up (false by default, which means infinite)

    83      * @param string          $default  The default answer if none is given by the user

    84      *

    85      * @return mixed

    86      *

    87      * @throws \Exception When any of the validator returns an error

    88      */

    89     public function askAndValidate(OutputInterface $output, $question, $validator, $attempts = false, $default = null)

    90     {

    91         $error = null;

    92         while (false === $attempts || $attempts--) {

    93             if (null !== $error) {

    94                 $output->writeln($this->getHelperSet()->get('formatter')->formatBlock($error->getMessage(), 'error'));

    95             }

    96 

    97             $value = $this->ask($output, $question, $default);

    98 

    99             try {

   100                 return call_user_func($validator, $value);

   101             } catch (\Exception $error) {

   102             }

   103         }

   104 

   105         throw $error;

   106     }

   107 

   108     /**

   109      * Sets the input stream to read from when interacting with the user.

   110      *

   111      * This is mainly useful for testing purpose.

   112      *

   113      * @param resource $stream The input stream

   114      */

   115     public function setInputStream($stream)

   116     {

   117         $this->inputStream = $stream;

   118     }

   119 

   120     /**

   121      * Returns the helper's canonical name

   122      */

   123     public function getName()

   124     {

   125         return 'dialog';

   126     }

   127 }