README

Closure unwrapper especially suited for Laravel PDO.

Requirements

Note

Older versions have outdated dependency requirements. If you cannot prepare the latest environment, please refer to past releases.

Installing

composer require mpyw/unclosure

Examples

Call PDO::setAttribute() after database connection has been established

<?php

use Mpyw\Unclosure\Value;
use PDO;

function withEmulation(PDO $pdo, bool $enabled): PDO
{
    $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, $enabled);
    return $pdo;
}

$connector = function (string $dsn) {
    return new PDO($dsn);
};

// Eager Evaluation
$pdo = Value::withCallback($connector('sqlite::memory:'), 'withEmulation', true);

// Lazy Evaluation
$pdo = Value::withCallback($connector, 'withEmulation', true);
$pdo = $pdo('sqlite::memory:');

Temporarily change PDO attributes

<?php

use Mpyw\Unclosure\Value;
use PDO;

function switchingEmulationTo(bool $enabled, &$pdo, callable $callback, ...$args)
{
    return Value::withEffect(
        $pdo,
        function (PDO $pdo) use ($enabled) {
            $original = $pdo->getAttribute(PDO::ATTR_EMULATE_PREPARES);
            $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, $enabled);
            
            return function (PDO $pdo) use ($original) {
                $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, $original);
            };
        },
        $callback,
        ...$args
    );
}

$connector = function (string $dsn) {
    return new PDO($dsn);
};

// Eager Evaluation
$pdo = $connector('sqlite::memory:');
switchingEmulationTo(true, $pdo, function () use ($pdo) {
    // Run queries that require prepared statement emulation
});

// Lazy Evaluation
$pdo = $connector;
switchingEmulationTo(true, $pdo, function () use (&$pdo) {
    $pdo = $pdo('sqlite::memory:');
    
    // Run queries that require prepared statement emulation
});

API

Value::withCallback()

static mixed|Closure withCallback(mixed|Closure $value, callable $callback, mixed ...$args)

Call $callback($value, ...$args) or wrap its call into Closure.

• When you pass $value as Closure:
  • Return wrapped Closure which returns $callback($value(), ...$args).
• When you pass $value as a raw value:
  • Return $callback($value, ...$args).

Arguments and Return Value

(A) $value

$value(mixed ...$initialArgs): mixed

(B) $callback

$callback(mixed $value, ...$args): mixed

(C) Return Value

*(mixed ...$initialArgs): mixed

Value::withEffect()
Value::withEffectForEach()

public static withEffect(mixed|Closure &$value, callable $configurator, callable $callback, mixed ...$args): mixed
public static withEffectForEach((mixed|Closure)[] &$values, callable $configurator, callable $callback, mixed ...$args): mixed

Call $callback(...$args), watching new assignment on &$value. You can conditionally unwrap $value in your $callback by yourself.

• When you pass $value as Closure:
  • If $value has been unwrapped, configurations via $configurator are applied.
  • If $value still remains as Closure, all configurations are canceled.
• When you pass $value as a raw value:
  • Configurations via $conigurator are immediately applied.

Arguments and Return Value

(A) &$value

*(): mixed

(B) $configurator

$configurator(mixed $value): ?callable

(C) $configurator Return Value

*(mixed $value): void

(D) $callback

$callback(...$args): mixed