--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Helper;
+
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * The Dialog class provides helpers to interact with the user.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class DialogHelper extends Helper
+{
+ private $inputStream;
+
+ /**
+ * Asks a question to the user.
+ *
+ * @param OutputInterface $output An Output instance
+ * @param string|array $question The question to ask
+ * @param string $default The default answer if none is given by the user
+ *
+ * @return string The user answer
+ *
+ * @throws \RuntimeException If there is no data to read in the input stream
+ */
+ public function ask(OutputInterface $output, $question, $default = null)
+ {
+ $output->write($question);
+
+ $ret = fgets($this->inputStream ?: STDIN, 4096);
+ if (false === $ret) {
+ throw new \RuntimeException('Aborted');
+ }
+ $ret = trim($ret);
+
+ return strlen($ret) > 0 ? $ret : $default;
+ }
+
+ /**
+ * Asks a confirmation to the user.
+ *
+ * The question will be asked until the user answers by nothing, yes, or no.
+ *
+ * @param OutputInterface $output An Output instance
+ * @param string|array $question The question to ask
+ * @param Boolean $default The default answer if the user enters nothing
+ *
+ * @return Boolean true if the user has confirmed, false otherwise
+ */
+ public function askConfirmation(OutputInterface $output, $question, $default = true)
+ {
+ $answer = 'z';
+ while ($answer && !in_array(strtolower($answer[0]), array('y', 'n'))) {
+ $answer = $this->ask($output, $question);
+ }
+
+ if (false === $default) {
+ return $answer && 'y' == strtolower($answer[0]);
+ }
+
+ return !$answer || 'y' == strtolower($answer[0]);
+ }
+
+ /**
+ * Asks for a value and validates the response.
+ *
+ * The validator receives the data to validate. It must return the
+ * validated data when the data is valid and throw an exception
+ * otherwise.
+ *
+ * @param OutputInterface $output An Output instance
+ * @param string|array $question The question to ask
+ * @param callback $validator A PHP callback
+ * @param integer $attempts Max number of times to ask before giving up (false by default, which means infinite)
+ * @param string $default The default answer if none is given by the user
+ *
+ * @return mixed
+ *
+ * @throws \Exception When any of the validators return an error
+ */
+ public function askAndValidate(OutputInterface $output, $question, $validator, $attempts = false, $default = null)
+ {
+ $error = null;
+ while (false === $attempts || $attempts--) {
+ if (null !== $error) {
+ $output->writeln($this->getHelperSet()->get('formatter')->formatBlock($error->getMessage(), 'error'));
+ }
+
+ $value = $this->ask($output, $question, $default);
+
+ try {
+ return call_user_func($validator, $value);
+ } catch (\Exception $error) {
+ }
+ }
+
+ throw $error;
+ }
+
+ /**
+ * Sets the input stream to read from when interacting with the user.
+ *
+ * This is mainly useful for testing purpose.
+ *
+ * @param resource $stream The input stream
+ */
+ public function setInputStream($stream)
+ {
+ $this->inputStream = $stream;
+ }
+
+ /**
+ * Returns the helper's input stream
+ *
+ * @return string
+ */
+ public function getInputStream()
+ {
+ return $this->inputStream;
+ }
+
+ /**
+ * Returns the helper's canonical name.
+ *
+ * @return string The helper name
+ */
+ public function getName()
+ {
+ return 'dialog';
+ }
+}