05 List and Get Handlers

Goal

Add handleList and handleGet functions that use ItemStore instead of a hardcoded array, and wire them into a router script. After this page the server returns items from SQLite.

Prerequisites

• Store Layer — the ItemStore class with list and get

A Testable Handler Shape

The beginner tier's 08 Hello HTTP read $_SERVER['REQUEST_URI'] directly inside the routing script. That's fine for a single file, but it makes handlers impossible to test without actually starting a server and making an HTTP request — PHP has no built-in equivalent to Go's httptest.

The fix: write each handler as a plain function that takes explicit arguments (never touches $_SERVER or superglobals itself) and returns [statusCode, body] instead of calling http_response_code/echo directly. The router script — which does read superglobals — becomes a thin layer that calls the right handler and applies its returned status/body. Page 08's tests call these functions directly, no server involved.

The Handlers

Create handlers.php:

<?php
require_once __DIR__ . '/store.php';

function handleList(PDO $pdo): array {
    $store = new ItemStore($pdo);
    $items = array_map(fn(Item $item) => $item->toArray(), $store->list());
    return [200, $items];
}

function handleGet(PDO $pdo, string $id): array {
    if (!ctype_digit($id)) {
        return [400, ["error" => "bad id"]];
    }

    $store = new ItemStore($pdo);
    $item = $store->get((int) $id);

    if ($item === null) {
        return [404, ["error" => "not found"]];
    }

    return [200, $item->toArray()];
}

ctype_digit($id) checks that $id is composed entirely of digit characters — the router will already have matched \d+ via regex (see below), but the handler re-validates independently, since it might be called directly (as page 08's tests do) without going through the router's regex at all.

Wiring: Extend the Router

Update router.php (starting from the beginner tier's router.php, but reading from SQLite now instead of a hardcoded array):

<?php
require_once __DIR__ . '/db.php';
require_once __DIR__ . '/handlers.php';

header('Content-Type: application/json');

$pdo = openDb('items.db');
$path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
$method = $_SERVER['REQUEST_METHOD'];

if ($method === 'GET' && $path === '/items') {
    [$status, $body] = handleList($pdo);
} elseif ($method === 'GET' && preg_match('#^/items/(\d+)$#', $path, $matches)) {
    [$status, $body] = handleGet($pdo, $matches[1]);
} else {
    $status = 404;
    $body = ["error" => "not found"];
}

http_response_code($status);
echo json_encode($body);

parse_url(..., PHP_URL_PATH) strips any query string from REQUEST_URI before matching — the beginner tier's router compared the raw URI directly, which would have broken on a request like /items?limit=10.

Checkpoint

php -S localhost:8000 router.php

In a second terminal:

curl http://localhost:8000/items

Expected (empty database, so an empty array):

[]

curl -i http://localhost:8000/items/1

Expected: HTTP/1.1 404 Not Found and {"error":"not found"}.

Stop the server with Ctrl-C.

Next

Continue to 06 Create Handler.