Container::$parameters contains unresolved Statement instances

[xificurk]

Version: dev-master, 3.0.x, 2.4.x

Bug Description

Parameters attribute in generated DI container contain unresolved Nette\DI\Definitions\Statement instances.

Steps To Reproduce

Generate container with the following config:

parameters:
	bar: ::getenv(FOO)

The generated code of DI container will have something like this in constructor:

$this->parameters += [
	'bar' => Nette\PhpGenerator\Helpers::createObject('Nette\DI\Definitions\Statement', [
		'arguments' => ['FOO'],
		"\x00Nette\\DI\\Definitions\\Statement\x00entity" => ['', 'getenv'],
	]),
];

Expected Behavior

I would expect the parameters to be resolved the same way as they are if they are used as arguments in service definitions.

[xificurk]

Thank you ❤️

[dg]

I decided to remove this feature.

Resolving parameters takes time and performance, it can instantiate services, and so on, but nobody, in fact, uses parameters. Instead, I'll remove unresolved statements from code and it will be cleaner.

[dakujem]

A problem I had with Nette 2.x was that once you do actually want to quickly pull a parameter out of configuration, say for prototyping, it is not possible, because instead of a value, one gets a Statement object.
If it was possible to fetch the underlying value or "resolve" all or a subset of parameters, it would be awesome.
Something like the Resolver::completeArguments, that we could call on the container.

The usecase would be this:

$raw = $presenter->context->getParameters()['foo'];
$value = Something::resolve($raw);

// or
$value = $presenter->context->resolveParameter('foo');

// or
$presenter->context->resolveParameters();
$value = $presenter->context->getParameters()['foo'];

... I bet you get the idea, David @dg

I am aware that the use case is not a good practice, yet this does happen and is especially frustrating for people who have not mastered Nette, for example a React developer who just wants to quickly add this tiny parameter to the API for quick proof of concept...

[dakujem]

Resolving parameters takes time and performance

👍

[dg]

What about this way?

class Parameters
{
	private $params;

	function __construct(array $params)
	{
		$this->params = $params;
	}

	function get($key)
	{
		return $this->params[$key]
	}
}

Add it as service:

parameters:
	main:	
		a: ::getenv('xxx')
		b: xzy

service:
	- Parameters(%main%)

And then use $params = $presenter->context->getByType(Parameters::class); and $params->get('a') …

[dakujem]

I am injecting the parameters in groups, right.
A service like the oabove would "unpack" (evaluate) all the parameters, possibly not optimal for performance.

Anyway, this technique (injecting) is not something a newbie will come out with, trust me :-) I have been asked this over and over again ("How do I convert a Statement into a value?").