Untitled

<?php
function addEmployee($id,$title, $grade){
    //ищит следубщее ид
    $maxId = 0;
    $lines = file("books.txt");
    foreach ($lines as $line){
        $employee = explode(";", $line);
        if(intval($employee[0]) > $maxId){
            $maxId = intval($employee[0]);
        }
    }

    //пишет файл
    $newEmployee =($maxId + 1) . urlencode($id) . ";" . urlencode($title) . ";" . urlencode($grade) .  PHP_EOL;
    file_put_contents("books.txt", $newEmployee, FILE_APPEND);

}

if ($_SERVER["REQUEST_METHOD"] === "POST"){
    $id = $_POST["id"];
    $title = $_POST["title"];
    $grade = $_POST["grade"];
    //сохранение

    addEmployee($id, $title, $grade);
    header("Location: ../index.php");
}
?>
<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <link rel="stylesheet" type="text/css" href="styles.css">
    <title>LisaAutor</title>
</head>
<body id="book-form-page">

<div id="root">

    <nav>
        <a href="../index.php" id="book-list-link">Raamatud</a>
        <a href="book-add.php" id="book-form-link">Lisa raamat</a>
        <a href="author-list.php" id="author-list-link">Autorid</a>
        <a href="author-add.php" id="author-form-link">Lisa autor</a>
    </nav>

    <main>

        <form id="input-form" method="post">

            <input name="id" type="hidden" value="">

            <div class="label">Pealkiri</div>
            <div class="input"><input id="title" name="title" type="text" value=""></div>


            <div class="label">Hinne:</div>
            <div class="input">
                <input type="radio" name="grade" value="1">1
                <input type="radio" name="grade" value="2">2
                <input type="radio" name="grade" value="3">3
                <input type="radio" name="grade" value="4">4
                <input type="radio" name="grade" value="5">5
            </div>

            <div class="br"></div>

            <div class="label">Loetud</div>
            <div class="input"><input id="isRead" name="isRead" type="checkbox"/></div>

            <div class="br"></div>

            <div class="label"></div>

            <div class="input button2">
                <td><input class="button" name="submitButton" type="submit" value="Salvesta"></td>
            </div>

        </form>


    </main>

    <footer>
        ICD0007 Näidisrakendus
    </footer>

</div>

</body>
</html>