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？
我file_get_contents用来获取远程定价（每天更新），substr用来只保留我想要的部分（从输出中剥离货币符号和其他数据，只保留数字）并file_put_contents用来将它存储到我引用的缓存目录中到以后。
这就是我现在所拥有的：-
<?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¤cy=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¤cy=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¤cy=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¤cy=1');
$substr_LG_US = substr($cache_LG_US,17,2);
file_put_contents($cachefile_LG_US, $substr_LG_US);
}
当只有两种产品 (10和20) 和两种货币 (1和2) 时，这种手动方式有效，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扩大到至少 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。
心有法竹2回答
-
Smart猫小萌
绝对地。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¤cy=%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），因此我们可以轻松定义：我们要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 -
ITMISS
如果我正确地解释了代码，您想要查找两种货币的两种产品。这可以在您定义产品和货币后使用嵌套的 foreach 循环来完成。$cacheDirectory = $_SERVER['DOCUMENT_ROOT'] . '/cache/';$url = 'https://remotedomain.com/?get=price';const MAX_CACHE_TIME = 1600;// Optional$output = [];$productList = [ [ 'id' => 10, 'name' => 'SM', ], [ 'id' => 20, 'name' => 'LG', ]];$currencies = [ 'US' => 1, 'EU' => 2,];foreach ($productList as $product) { foreach ($currencies as $currencyName => $currencyId) { $cacheFile = $cacheDirectory . $product['name'] . '_' . $currencyName . '.cache'; if (!file_exists($cacheFile) || filemtime($cacheFile) > MAX_CACHE_TIME) { // No cache or too old $data = file_get_contents($url . '&product=' . $product['id'] . '¤cy=' . $currencyId); $relevantData = substr($data, 17, 2); file_put_contents($cacheFile, $relevantData); // Optional, put the data in an array $output[$product['id']][$currencyId] = $relevantData; } else { $output[$product['id']][$currencyId] = file_get_contents($cacheFile); } }}// Read outputwith $output[10]['US'] for example
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