TL;DR

I recently released App::Easer version 0.008.

After the introducing App::Easer new defaults handling, I was going to start writing a tutorial (remember Tutorials for modules?) and I immediately hit a block.

In App::Easer, if you have an option (say foo) you can define many ways to get its value, e.g. from command line options, the environment, from files, as well as setting a default, like this:

{
    help        => 'the foo and the bar',
    getopt      => 'foo|f=s',
    environment => 'APP_FOO',
    default     => 'baz',
}

Fact is that, in my case, most of the times the environment variables are set with a prefix tied to my application and a suffix tied to the parameter name, in uppercase.

So I thought that it would be so useful to have this out of the box!

Which led me to wishing support for this interface too:

{
    help        => 'the foo and the bar',
    getopt      => 'foo|f=s',
    environment => 1,
    default     => 'baz',
},
{
    help        => 'the bar and stop',
    getopt      => 'bar|b=!',
    environment => 'WHATEVER_YOU_WANT',
    default     => 'galook',
}

That is:

  • if key environment is set to value/string 1 (exactly) it means that the name of the environment variable should be generated automatically;

  • otherwise it’s just used out of the box (like in the case of option bar in the second example).

To get this behaviour… just set configuration variable auto-environment.

This requires also the introduction of an additional configuration in the configuration section, to set the name of the application, which doubles down as the prefix used for generating environment variables names:

my $app = {
    configuration => {
        'auto-environment' => 1,       # use the new feature
        name               => 'myapp', # prefix for env var names
        ...
    },
    commands => {
        MAIN => {
            options => [
                {
                    help        => 'the foo and the bar',
                    getopt      => 'foo|f=s',
                    environment => 1,
                    default     => 'baz',
                },
                ...

The example above would generate the environment variable name MYAPP_FOO, as you can imagine.

So… every time I mess around using App::Easer I find some more corners that should be ironed out… I’m not whether I like this or not!