ArrayHelper::getValue

[i-panov]

Hi there! I wanted to propose, as an alternative, to make the third parameter (default) of this function a callback. This would be useful if the default value is necessary, for example, to be obtained from the database or in some other difficult way. I do not suggest changing the API. I want the function to support this parameter with both value and callback. If a calback is transmitted, it will be called to get the value, otherwise it will be used as a value.

[rob006]

What if default value should be a Closure? There is no way to distinguish between value-callback and value-generator-callback.

[i-panov]

@rob006 Strange, but I never had this. Why do you need it at all? Can you give an example in which you would need a value-callback?

[rob006]

Why do you need it at all?

Because Closure is a valid value and we should not assume nobody will never need it?

Strange, but I never had this

I never need default value generated by callback. :) And even I need, I can always use ?? for this:

$value = ArrayHelper::getValue(/* ... */) ?? (function() {/* ... */})();

[i-panov]

@rob006

1. This syntax is very long and difficult to understand (especially if we recall that php still does not have short lambdas). In addition, it will work only 7+.
2. Just see how it works in Java: Optional.orElseGet. True, it is done there by a separate method, but this is due to static typing. Actually, I really like how the Optional type works there. Do you want to do the same in php? I could even write it myself.

[rob006]

Yii 3 already requires PHP 7.1. And if you want short lambda, you may do this even simpler:

$value = ArrayHelper::getValue(/* ... */) ?? $this->calculateValue();

It is short, efficient and does not require to know method internals to understand what is happening - basics of PHP should be enough. For complicate callbacks it is better to use regular if anyway.

[i-panov]

Yii 3 already requires PHP 7.1

Yii 3 hasn't been released yet. Many projects are still in PHP 5.6 (or even lower).

you may do this even simpler

I agree - this is an option. I just do not consider it a good idea to write functions that are used only in one place. The function should be used at least in two places, otherwise there was no point and to take these actions into a separate function. Then it's really easier to really use if.

[rob006]

Yii 3 hasn't been released yet. Many projects are still in PHP 5.6 (or even lower).

This repo is for Yii 3 - even if we implement your idea, it will not work on PHP 5.6. And we can't change getValue() behavior in Yii 2 - it will break BC.

I just do not consider it a good idea to write functions that are used only in one place. The function should be used at least in two places, otherwise there was no point and to take these actions into a separate function.

You're simply wrong. Usually main benefit of extracting code to separate methods is improving readability (it is easier to understand what is happening if you need to read 5 method calls than ~100 lines of code) and simplifying maintenance (it is harder to break something if you're editing small blocks of code). Code reusable should not be the only reason for extracting code to methods.

[samdark]

// I've moved the issue to 3.0 since 2.0 isn't accepting enhancements (almost) since two versions ago.

[samdark]

Closing since it's PHP 7.4 and #11 (comment) is good.