[Console] Add a RepeatedQuestion

[GuilhemN]

Actually when I want to ask several times the same question with SymfonyStyle i have a very verbose output:

What do you want? [default]:
> foo

What do you want? [default]:
> bar

What do you want? [default]:
>

I propose to introduce a RepeatedQuestion. It could be implemented like that:

class RepeatedQuestion extends Question
{
    private $generator;

    public function __construct($question, \Generator $generator)
    {
        parent::__construct($question);
        $this->generator = $generator;
    }

    public function addAnswer($answer)
    {
         $this->generator->send($answer);
    }

    public function shouldContinue(): bool
    {
        return $this->generator->valid();
    }

    public function getDefault()
    {
        return $this->generator->current();
    }
}

It would be used like that:

$question = new RepeatedQuestion(call_user_func(function() use ($default) {
    do {
        $answer = yield $default;
    } while ($answer !== $default);
}));
foreach ($helper->askQuestion($question) as $answer) {
    // do what you want
}

And the command output would be:

What do you want?
[default] > foo
[default] > bar
[default] >

WDYT?

[linaori]

Looks like a valid case to me

[GuilhemN]

BTW it could also be used for things like multiline answer. Maybe we should choose a name showing this use case as well ?

[jameshalsall]

This can easily be implemented in user land with Question

[GuilhemN]

@jameshalsall how would you do that ? That's not that easy and would probably need some hacks.
Anyway even if that's doable in userland i don't understand why it wouldn't be supported by the core to make it easier to use.

[sstok]

Depending on there relationship this is not as easy as it seems, in https://github.com/rollerworks/SkeletonDancer I started with a collection of questions, but then I wanted to add support for conditional questions (only ask when x) and then it become complicated.

So Instead of adding all to a collection, each question is asked by a Questioner that keeps track of all questions, but instead of using the Symfony Console Question directly it uses a wrapper that creates the Question at a later state so that the default can be passed https://github.com/rollerworks/SkeletonDancer/blob/master/src/Question.php

[jameshalsall]

@Ener-Getick at a simple level off the top of my head...

$answers = [];
$question = new Question('What is foo?', 'bar');
do {
    $answers[] = $questionHelper->ask($input, $output, $question);
} while ($answer !== 'bar');

$output->writeln('You answered with ' , implode(', ', $answers);

@sstok it may well get more complicated if you want to only ask Y when X has a certain answer, but that's more like a Questionnaire component, which may well have some value

[GuilhemN]

@jameshalsall yes but as i said that's very verbose.

[jameshalsall]

it's no more verbose than your suggested implementation, imo

[GuilhemN]

@jameshalsall the console output is verbose, not the call to ask :P

[sstok]

@jameshalsall Good point, that's actually something I want to do in the long run :) but that will take some time.

[javiereguiluz]

I'm 👎 for this proposed feature:

1. Having a repeated question in a command is not that common (unlike forms, where you always have a repeated password field, for example).
2. The output is "verbose" ... because the command showed an example is verbose in the first place. You are asking 3 or 4 times the same thing, so it's a verbose command originally.
3. It can be solved with existing features. E.g.

What do you want? (separate the values with a comma):
> foo, bar, baz

[GuilhemN]

@javiereguiluz i want to use this in my QuickInstallBundle to reconfigure an app.
It is very common in Configuration to have array nodes and everytime to configure one of them it is verbose (see this example). When you don't have a default and you use small values you can of course use , but you have to explain it. But what if you want to ask for urls, usernames, etc?

BTW I think it would also be useful for multiline input (mails, comments, ...).

[javiereguiluz]

Closing it because the related issue (#19699) was closed as "won't fix".