[5.6] Add callback support to "optional"

[JosephSilber]

Lets you pipe the value into an outside function, with the guarantee that you're not passing it null:

return optional($modelOrNull, function ($definitelyTheModel) {
    return doSomethingWithTheModel($definitelyTheModel);
});

[BrandonShar]

how is this better than a ternary or an if statement?

I love the optional helper, but I think it's getting stretched a bit far lately.

[JosephSilber]

A ternary is insufficient when the value comes from a function/expression.

[BrandonShar]

Ah ok, so this would be for cases where you might have a result of one function that you want to pass as an argument to another function. I don't think that's a common pattern for me, but that may be because I haven't been looking for it. It would probably be helpful to update the example since the current one would be more succinct as a ternary.

There was another PR recently where a contributor wanted to add similar functionality to tap and I thought creating a when helper might be a better idea. Maybe that would be the same case here?

Personally, I like keeping optional as nothing more than a PHP version of Ruby's & operator, so I have a bit of a bias.

[derekmd]

transform() used internally by API resources can do this: https://laravel.com/docs/5.6/helpers#method-transform.

It will call the Closure when the value passes filled().

https://github.com/laravel/framework/blob/5.6/src/Illuminate/Support/helpers.php#L1121-L1142

Otherwise it returns null by default.

[crynobone]

I find it odd that optional() may now not return Illuminate\Support\Optional.

optional($user, function ($user) {
    return $user->sendResetPassword();
})->getInvalidProperty->dump;

It now would throws exception.

[garygreen]

@BrandonShar

I love the optional helper, but I think it's getting stretched a bit far lately.

Do a PR to remove the Optional helper. I'd +1 it. tap tap tap tap dat all day 😄

[JosephSilber]

@derekmd the transform helper checks for filled, as you've noted. Not null.

@crynobone I don't see that confusing at all. These are two different uses of the optional helper. Think of it as an overloaded method with a different return type.