Description

Given a command option defined like this:

$this->addOption('save', 's', InputOption::VALUE_OPTIONAL, 'A file to save the results to', 'default.csv');

I would like to support three different behaviors in my application:

1. If --save is omitted, my command will write the results to stdout
2. If --save is provided (without any value), I would like it to default to the given default value of default.csv
3. If --save=elsewhere.csv is provided, I would like to obtain that user-defined value of elsewhere.csv

Symfony does not seem to currently support this because:

• Input::getOption() always returns the default value in scenarios 1 and 2 above
• Input::getOptions() does the same
• Input::hasOption() returns whether the option was defined by the command, not whether the command received the option
• Input::$options has the information I need but it's not public

In other words, it's currently impossible to differentiate between scenarios 1 and 2.

Example

My ideal solution would be one where I can simply call getOption('save') and get some indication that the user did not specify the option at all, similar to how VALUE_NONE works. Perhaps it could return null in that case?

To avoid breaking BC, perhaps we'd also need a new flag like InputOption::VALUE_NULL_IF_OMITTED that can be ORed with VALUE_OPTIONAL to enable this behavior?

I'm definitely open to other ideas too.

Workarounds

Some workarounds do exist for this, but none of them seem ideal for my requirements:

1. Extend the Input class to add this functionality myself
2. Use two different options instead of one; add manual validation to ensure the user didn't provide both
3. Follow the Unix Way and always output to stdout; let the user pipe that into a file if they really want to (doesn't meet my requirements)

But perhaps Symfony does support what I'm looking for and I'm just missing it?