php - 是否有更好的循环遍历这些 PHP 代码的方法，也许使用 foreach 循环？

Question

我使用 file_get_contents 获取远程定价(每天更新)，使用 substr 只保留我想要的部分(从输出并只保留数字)并使用 file_put_contents 将其存储到缓存目录中，我稍后会提到该目录。

这就是我现在拥有的:-

<?php

$cacheDirectory = $_SERVER['DOCUMENT_ROOT'] . '/cache/';

// Small Plan - US
$cachefile_SM_US = $cacheDirectory . 'SM_US.cache';

if(file_exists($cachefile_SM_US)) {
    if(time() - filemtime($cachefile_SM_US) > 1600) {
        // too old , re-fetch
        $cache_SM_US = file_get_contents('https://remotedomain.com/?get=price&product=10&currency=1');
        $substr_SM_US = substr($cache_SM_US,17,2);
        file_put_contents($cachefile_SM_US, $substr_SM_US);
        } else {
            // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_SM_US = file_get_contents('https://remotedomain.com/?get=price&product=10&currency=1');
    $substr_SM_US = substr($cache_SM_US,17,2);
    file_put_contents($cachefile_SM_US, $substr_SM_US);
}

// Large Plan - US
$cachefile_LG_US = $cacheDirectory . 'LG_US.cache';

if(file_exists($cachefile_LG_US)) {
    if(time() - filemtime($cachefile_LG_US) > 1600) {
        // too old , re-fetch
        $cache_LG_US = file_get_contents('https://remotedomain.com/?get=price&product=20&currency=1');
        $substr_LG_US = substr($cache_LG_US,17,2);
        file_put_contents($cachefile_LG_US, $substr_LG_US);
    } else {
        // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_LG_US = file_get_contents('https://remotedomain.com/?get=price&product=20&currency=1');
    $substr_LG_US = substr($cache_LG_US,17,2);
    file_put_contents($cachefile_LG_US, $substr_LG_US);
}

// Small Plan - EU
$cachefile_SM_EU = $cacheDirectory . 'SM_EU.cache';

if(file_exists($cachefile_SM_EU)) {
    if(time() - filemtime($cachefile_SM_EU) > 1600) {
        // too old , re-fetch
        $cache_SM_EU = file_get_contents('https://remotedomain.com/?get=price&product=10&currency=2');
        $substr_SM_EU = substr($cache_SM_EU,17,2);
        file_put_contents($cachefile_SM_EU, $substr_SM_EU);
        } else {
            // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_SM_EU = file_get_contents('https://remotedomain.com/?get=price&product=10&currency=2');
    $substr_SM_EU = substr($cache_SM_EU,17,2);
    file_put_contents($cachefile_SM_EU, $substr_SM_EU);
}

// Large Plan - EU
$cachefile_LG_EU = $cacheDirectory . 'LG_EU.cache';

if(file_exists($cachefile_LG_EU)) {
    if(time() - filemtime($cachefile_LG_EU) > 1600) {
        // too old , re-fetch
        $cache_LG_EU = file_get_contents('https://remotedomain.com/?get=price&product=20&currency=2');
        $substr_LG_EU = substr($cache_LG_EU,17,2);
        file_put_contents($cachefile_LG_EU, $substr_LG_EU);
    } else {
        // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_LG_EU = file_get_contents('https://remotedomain.com/?get=price&product=20&currency=2');
    $substr_LG_EU = substr($cache_LG_EU,17,2);
    file_put_contents($cachefile_LG_EU, $substr_LG_EU);
}

?>

当只有两种产品(10 和20)和两种货币(1 和2) 因为我只需要这样做 4 次就可以获得我需要的所有定价。

但是，我打算将产品数量显着增加到至少 12 种产品和 9 种货币，因此手动完成它们是不现实的。

我相信这可以通过 PHP foreach 循环更有效地完成，但我尝试了几天但没能成功，这可能是因为我对这个概念的理解较弱。

我设法把它分成了这个:-

<?php

$cacheDirectory = $_SERVER['DOCUMENT_ROOT'] . '/cache/';

$url = 'https://remotedomain.com/?get=price';
$productA = 10;
$productB = 20;
$USD = 1;
$EUR = 2;

// Small Plan - US
$cachefile_SM_US = $cacheDirectory . 'SM_US.cache';

if(file_exists($cachefile_SM_US)) {
    if(time() - filemtime($cachefile_SM_US) > 1600) {
        // too old , re-fetch
        $cache_SM_US = file_get_contents($url . '&product=' . $productA . '&currency=' . $USD);
        $substr_SM_US = substr($cache_SM_US,17,2);
        file_put_contents($cachefile_SM_US, $substr_SM_US);
        } else {
            // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_SM_US = file_get_contents($url . '&product=' . $productA . '&currency=' . $USD);
    $substr_SM_US = substr($cache_SM_US,17,2);
    file_put_contents($cachefile_SM_US, $substr_SM_US);
}

// Large Plan - US
$cachefile_LG_US = $cacheDirectory . 'LG_US.cache';

if(file_exists($cachefile_LG_US)) {
    if(time() - filemtime($cachefile_LG_US) > 1600) {
        // too old , re-fetch
        $cache_LG_US = file_get_contents($url . '&product=' . $productB . '&currency=' . $USD);
        $substr_LG_US = substr($cache_LG_US,17,2);
        file_put_contents($cachefile_LG_US, $substr_LG_US);
    } else {
        // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_LG_US = file_get_contents($url . '&product=' . $productB . '&currency=' . $USD);
    $substr_LG_US = substr($cache_LG_US,17,2);
    file_put_contents($cachefile_LG_US, $substr_LG_US);
}

// Small Plan - EU
$cachefile_SM_EU = $cacheDirectory . 'SM_EU.cache';

if(file_exists($cachefile_SM_EU)) {
    if(time() - filemtime($cachefile_SM_EU) > 1600) {
        // too old , re-fetch
        $cache_SM_EU = file_get_contents($url . '&product=' . $productA . '&currency=' . $EUR);
        $substr_SM_EU = substr($cache_SM_EU,17,2);
        file_put_contents($cachefile_SM_EU, $substr_SM_EU);
        } else {
            // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_SM_EU = file_get_contents($url . '&product=' . $productA . '&currency=' . $EUR);
    $substr_SM_EU = substr($cache_SM_EU,17,2);
    file_put_contents($cachefile_SM_EU, $substr_SM_EU);
}

// Large Plan - EU
$cachefile_LG_EU = $cacheDirectory . 'LG_EU.cache';

if(file_exists($cachefile_LG_EU)) {
    if(time() - filemtime($cachefile_LG_EU) > 1600) {
        // too old , re-fetch
        $cache_LG_EU = file_get_contents($url . '&product=' . $productB . '&currency=' . $EUR);
        $substr_LG_EU = substr($cache_LG_EU,17,2);
        file_put_contents($cachefile_LG_EU, $substr_LG_EU);
    } else {
        // cache is still fresh
    }
} else {
    // no cache, create one
    $cache_LG_EU = file_get_contents($url . '&product=' . $productB . '&currency=' . $EUR);
    $substr_LG_EU = substr($cache_LG_EU,17,2);
    file_put_contents($cachefile_LG_EU, $substr_LG_EU);
}

?>

我现在面临的挑战是如何将其转换为循环遍历每种产品和每种货币的 foreach 循环。

感谢正确方向的指示。

谢谢!

Answer 1

当然。看看这个例子:)

<?php declare(strict_types=1);

interface CacheNormalizer
{
    public function normalize(string $text): string;
}

interface PlanDomainToCache
{
    public function buildUrl(Plan $plan): string;
}

final class CachedRemoteSiteManager
{
    /** @var int Time To Live Cache */
    private $timeToLive;

    /** @var CacheNormalizer */
    private $cacheNormalizer;

    /** @var PlanDomainToCache */
    private $planDomainToCache;

    public function __construct(
        int $timeToLive,
        CacheNormalizer $cacheNormalizer,
        PlanDomainToCache $planDomainToCache
    ) {
        $this->timeToLive = $timeToLive;
        $this->cacheNormalizer = $cacheNormalizer;
        $this->planDomainToCache = $planDomainToCache;
    }

    public function updateIfNecessary(Plan $plan): void
    {
        if ($this->shouldCreateOrUpdateCache($plan)) {
            $this->createOrUpdateCache($plan);
        }
    }

    private function shouldCreateOrUpdateCache(Plan $plan): bool
    {
        return !file_exists($plan->cacheDirectory())
            || time() - filemtime($plan->cacheDirectory()) > $this->timeToLive;
    }

    private function createOrUpdateCache(Plan $plan): void
    {
        $urlToCache = $this->planDomainToCache->buildUrl($plan);
        $textToCache = file_get_contents($urlToCache);

        file_put_contents(
            $plan->cacheDirectory(),
            $this->cacheNormalizer->normalize($textToCache)
        );
    }
}

final class Plan
{
    /** @var string */
    private $cacheDirectory;

    /** @var int */
    private $product;

    /** @var int */
    private $currency;

    public function __construct(string $cacheDir, int $product, int $currency)
    {
        $this->cacheDirectory = $cacheDir;
        $this->product = $product;
        $this->currency = $currency;
    }

    public function cacheDirectory(): string
    {
        return $this->cacheDirectory;
    }

    public function product(): int
    {
        return $this->product;
    }

    public function currency(): int
    {
        return $this->currency;
    }
}

// Usage example:

$cacheDirectory = $_SERVER['DOCUMENT_ROOT'] . '/cache/';
$productA = 10;
$productB = 20;
$USD = 1;
$EUR = 2;

/** @var Plan[] */
$plansToCache = [
    new Plan($cacheDirectory . 'SM_US.cache', $productA, $USD),
    new Plan($cacheDirectory . 'LG_US.cache', $productB, $USD),
    new Plan($cacheDirectory . 'SM_EU.cache', $productA, $EUR),
    new Plan($cacheDirectory . 'LG_EU.cache', $productB, $EUR),
];

$cacheManager = new CachedRemoteSiteManager(
    $cacheTtl = 1600,
    new class implements CacheNormalizer {
        public function normalize(string $text): string
        {
            return substr($text, 17, 2);
        }
    },
    new class implements PlanDomainToCache {
        public function buildUrl(Plan $plan): string
        {
            return sprintf(
                'https://remotedomain.com/?get=price&product=%d&currency=%d',
                $plan->product(),
                $plan->currency()
            );
        }
    }
);

foreach ($plansToCache as $plan) {
    $cacheManager->updateIfNecessary($plan);
}

正如您在底部看到的，在“使用示例”中，我提取了所有细节(几乎所有细节)以便我们可以轻松定义:

• 我们希望如何规范化缓存数据(使用 CacheNormalizer)
• 我们要如何构建要缓存的 URL(使用 PlanDomainToCache)。

更新:

如果您想了解如何从结束代码中提取/解耦每个细节，即使对于“持久性”层也向上反转依赖关系:https://gist.github.com/Chemaclass/01d3f42685ff69f6897192202a32014d