.. index::
single: Console Helpers; Dialog Helper
The :class:`Symfony\\Component\\Console\\Helper\\DialogHelper` provides functions to ask the user for more information. It is included in the default helper set, which you can get by calling :method:`Symfony\\Component\\Console\\Command\\Command::getHelperSet`:
$dialog = $this->getHelperSet()->get('dialog');
All the methods inside the Dialog Helper have an :class:`Symfony\\Component\\Console\\Output\\OutputInterface` as first the argument, the question as the second argument and the default value as last argument.
Suppose you want to confirm an action before actually executing it. Add the following to your command:
// ...
if (!$dialog->askConfirmation(
$output,
'<question>Continue with this action?</question>',
false
)) {
return;
}
In this case, the user will be asked "Continue with this action?", and will return
true if the user answers with y or false in any other case. The third
argument to askConfirmation is the default value to return if the user doesn't
enter any input.
You can also ask question with more than a simple yes/no answer. For instance, if you want to know a bundle name, you can add this to your command:
// ...
$bundle = $dialog->ask(
$output,
'Please enter the name of the bundle',
'AcmeDemoBundle'
);
The user will be asked "Please enter the name of the bundle". She can type
some name which will be returned by the ask method. If she leaves it empty,
the default value (AcmeDemoBundle here) is returned.
.. versionadded:: 2.2
Autocompletion for questions was added in Symfony 2.2.
You can also specify an array of potential answers for a given question. These will be autocompleted as the user types:
$dialog = $this->getHelperSet()->get('dialog');
$bundleNames = array('AcmeDemoBundle', 'AcmeBlogBundle', 'AcmeStoreBundle');
$name = $dialog->ask(
$output,
'Please enter the name of a bundle',
'FooBundle',
$bundleNames
);
.. versionadded:: 2.2
The ``askHiddenResponse`` method was added in Symfony 2.2.
You can also ask a question and hide the response. This is particularly convenient for passwords:
$dialog = $this->getHelperSet()->get('dialog');
$password = $dialog->askHiddenResponse(
$output,
'What is the database password?',
false
);
Caution!
When you ask for a hidden response, Symfony will use either a binary, change
stty mode or use another trick to hide the response. If none is available,
it will fallback and allow the response to be visible unless you pass false
as the third argument like in the example above. In this case, a RuntimeException
would be thrown.
You can even validate the answer. For instance, in the last example you asked
for the bundle name. Following the Symfony2 naming conventions, it should
be suffixed with Bundle. You can validate that by using the
:method:`Symfony\\Component\\Console\\Helper\\DialogHelper::askAndValidate`
method:
// ...
$bundle = $dialog->askAndValidate(
$output,
'Please enter the name of the bundle',
function ($answer) {
if ('Bundle' !== substr($answer, -6)) {
throw new \RunTimeException(
'The name of the bundle should be suffixed with \'Bundle\''
);
}
return $answer;
},
false,
'AcmeDemoBundle'
);
This methods has 2 new arguments, the full signature is:
askAndValidate(
OutputInterface $output,
string|array $question,
callback $validator,
integer $attempts = false,
string $default = null
)
The $validator is a callback which handles the validation. It should
throw an exception if there is something wrong. The exception message is displayed
in the console, so it is a good practice to put some useful information in it. The callback
function should also return the value of the user's input if the validation was successful.
You can set the max number of times to ask in the $attempts argument.
If you reach this max number it will use the default value, which is given
in the last argument. Using false means the amount of attempts is infinite.
The user will be asked as long as he provides an invalid answer and will only
be able to proceed if her input is valid.
.. versionadded:: 2.2
The ``askHiddenResponseAndValidate`` method was added in Symfony 2.2.
You can also ask and validate a hidden response:
$dialog = $this->getHelperSet()->get('dialog');
$validator = function ($value) {
if (trim($value) == '') {
throw new \Exception('The password can not be empty');
}
};
$password = $dialog->askHiddenResponseAndValidate(
$output,
'Please enter your password',
$validator,
20,
false
);
If you want to allow the response to be visible if it cannot be hidden for some reason, pass true as the fifth argument.
.. versionadded:: 2.2
The :method:`Symfony\\Component\\Console\\Helper\\DialogHelper::select` method
was added in Symfony 2.2.
If you have a predefined set of answers the user can choose from, you
could use the ask method described above or, to make sure the user
provided a correct answer, the askAndValidate method. Both have
the disadvantage that you need to handle incorrect values yourself.
Instead, you can use the :method:`Symfony\\Component\\Console\\Helper\\DialogHelper::select` method, which makes sure that the user can only enter a valid string from a predefined list:
$dialog = $app->getHelperSet()->get('dialog');
$colors = array('red', 'blue', 'yellow');
$color = $dialog->select(
$output,
'Please select your favorite color (default to red)',
$colors,
0
);
$output->writeln('You have just selected: ' . $colors[$color]);
// ... do something with the color
The option which should be selected by default is provided with the fourth
argument. The default is null, which means that no option is the default one.
If the user enters an invalid string, an error message is shown and the user
is asked to provide the answer another time, until she enters a valid string
or the maximum attempts is reached (which you can define in the fifth
argument). The default value for the attempts is false, which means infinite
attempts. You can define your own error message in the sixth argument.
.. versionadded:: 2.3
Multiselect support was added in Symfony 2.3.
Sometimes, multiple answers can be given. The DialogHelper provides this
feature using comma separated values. This is disabled by default, to enable
this set the seventh argument to true:
// ...
$selected = $dialog->select(
$output,
'Please select your favorite color (default to red)',
$colors,
0,
false,
'Value "%s" is invalid',
true // enable multiselect
);
$selectedColors = array_map(function($c) use ($colors) {
return $colors[$c];
}, $selected);
$output->writeln('You have just selected: ' . implode(', ', $selectedColors));
Now, when the user enters 1,2, the result will be: You have just selected: blue, yellow.
If you want to write a unit test for a command which expects some kind of input from the command line, you need to overwrite the HelperSet used by the command:
use Symfony\Component\Console\Helper\DialogHelper;
use Symfony\Component\Console\Helper\HelperSet;
// ...
public function testExecute()
{
// ...
$commandTester = new CommandTester($command);
$dialog = $command->getHelper('dialog');
$dialog->setInputStream($this->getInputStream('Test\n'));
// Equals to a user inputing "Test" and hitting ENTER
// If you need to enter a confirmation, "yes\n" will work
$commandTester->execute(array('command' => $command->getName()));
// $this->assertRegExp('/.../', $commandTester->getDisplay());
}
protected function getInputStream($input)
{
$stream = fopen('php://memory', 'r+', false);
fputs($stream, $input);
rewind($stream);
return $stream;
}
By setting the inputStream of the DialogHelper, you imitate what the
console would do internally with all user input through the cli. This way
you can test any user interaction (even complex ones) by passing an appropriate
input stream.