React.js与PHP后端集成：构建RESTful API应用教程

[
    { "offerId": 1, "productTitle": "Laptop", "vendorId": 101, "price": 1200 },
    { "offerId": 2, "productTitle": "Mouse", "vendorId": 101, "price": 25 },
    { "offerId": 3, "productTitle": "Keyboard", "vendorId": 102, "price": 75 },
    { "offerId": 4, "productTitle": "Monitor", "vendorId": 103, "price": 300 },
    { "offerId": 5, "productTitle": "Webcam", "vendorId": 102, "price": 50 },
    { "offerId": 6, "productTitle": "Headphones", "vendorId": 101, "price": 150 }
]

<?php

// 设置CORS头，允许React开发服务器访问
header("Access-Control-Allow-Origin: http://localhost:3000"); // 替换为你的React应用地址
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: GET, POST, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

// 处理OPTIONS请求，用于CORS预检
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit();
}

/**
 * The interface provides the contract for different readers
 * E.g. it can be XML/JSON Remote Endpoint, or CSV/JSON/XML local files
 */
interface ReaderInterface
{
    /**
     * Read in incoming data and parse to objects
     */
    public function read(string $input): OfferCollectionInterface;
}

/**
 * Interface of Data Transfer Object, that represents external JSON data
 */
interface OfferInterface
{
}

/**
 * Interface for The Collection class that contains Offers
 */
interface OfferCollectionInterface
{
    public function get(int $index): OfferInterface;
    public function getIterator(): Iterator;
}

/* *********************************** */

class Offer implements OfferInterface
{
    public $offerId;
    public $productTitle;
    public $vendorId;
    public $price;

    public function __toString(): string
    {
        return "$this->offerId | $this->productTitle | $this->vendorId | $this->price\n";
    }
}

class OfferCollection implements OfferCollectionInterface
{
    private $offersList = array();

    public function __construct($data)
    {
        if (is_array($data)) {
            foreach ($data as $json_object) {
                $offer = new Offer();
                $offer->offerId = $json_object->offerId;
                $offer->productTitle = $json_object->productTitle;
                $offer->vendorId = $json_object->vendorId;
                $offer->price = $json_object->price;

                array_push($this->offersList, $offer);
            }
        }
    }

    public function get(int $index): OfferInterface
    {
        return $this->offersList[$index];
    }

    public function getIterator(): Iterator
    {
        return new ArrayIterator($this->offersList);
    }

    public function __toString(): string
    {
        return implode("\n", $this->offersList);
    }

    // 新增方法：将OfferCollection转换为数组，以便json_encode
    public function toArray(): array
    {
        $result = [];
        foreach ($this->offersList as $offer) {
            $result[] = [
                'offerId' => $offer->offerId,
                'productTitle' => $offer->productTitle,
                'vendorId' => $offer->vendorId,
                'price' => $offer->price,
            ];
        }
        return $result;
    }
}

class Reader implements ReaderInterface
{
    /**
     * Read in incoming data and parse to objects
     */
    public function read(string $input): OfferCollectionInterface
    {
        if ($input != null) {
            $content = file_get_contents($input);
            $json = json_decode($content);
            $result = new OfferCollection($json);

            return $result;
        }

        return new OfferCollection(null);
    }
}

class Logger
{
    private $filename = "logs.txt";

    public function info($message): void
    {
        $this->log($message, "INFO");
    }

    public function error($message): void
    {
        $this->log($message, "ERROR");
    }

    private function log($message, $type): void
    {
        $myfile = fopen($this->filename, "a") or die("Unable to open file!");
        $txt = "[$type] $message\n";
        fwrite($myfile, $txt);
        fclose($myfile);
    }
}

$json_url = 'data.json';

$json_reader = new Reader();
$offers_list = $json_reader->read($json_url);


function count_by_price_range($price_from, $price_to)
{
    global $offers_list;
    $count = 0;
    foreach ($offers_list->getIterator() as $offer) {
        if ($offer->price >= $price_from && $offer->price <= $price_to) {
            $count++;
        }
    }
    return $count;
}

function count_by_vendor_id($vendorId)
{
    global $offers_list;
    $count = 0;
    foreach ($offers_list->getIterator() as $offer) {
        if ($offer->vendorId == $vendorId) {
            $count++;
        }
    }
    return $count;
}

// 获取请求路径和参数
$request_uri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
$path_segments = explode('/', trim($request_uri, '/'));
$api_endpoint = end($path_segments); // 假设API路径的最后一段是功能名称

$logger = new Logger();
$response_data = [];
$status_code = 200;

switch ($api_endpoint) {
    case "count_by_price_range": {
        $price_from = $_GET['from'] ?? null;
        $price_to = $_GET['to'] ?? null;

        if ($price_from !== null && $price_to !== null) {
            $logger->info("Getting Count By Price Range From: $price_from TO $price_to");
            $response_data = ['count' => count_by_price_range((float)$price_from, (float)$price_to)];
        } else {
            $status_code = 400;
            $response_data = ['error' => 'Missing price range parameters (from, to).'];
        }
        break;
    }
    case "count_by_vendor_id": {
        $vendorId = $_GET['vendorId'] ?? null;
        if ($vendorId !== null) {
            $logger->info("Getting Count By vendor Id: $vendorId");
            $response_data = ['count' => count_by_vendor_id((int)$vendorId)];
        } else {
            $status_code = 400;
            $response_data = ['error' => 'Missing vendorId parameter.'];
        }
        break;
    }
    case "offers": { // 新增一个获取所有offer的接口
        $response_data = ['offers' => $offers_list->toArray()];
        break;
    }
    default: {
        $status_code = 404;
        $response_data = ['error' => 'API endpoint not found.'];
        break;
    }
}

http_response_code($status_code);
echo json_encode($response_data);

?>

header("Access-Control-Allow-Origin: http://localhost:3000"); // 允许来自React开发服务器的请求
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: GET, POST, OPTIONS"); // 允许的HTTP方法
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

// 处理OPTIONS请求，用于CORS预检
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit();
}