PHP多步骤表单数据传递：使用隐藏字段跨页面保持POST数据

<!-- form1.php -->
<form action="form2.php" method="post">
    <!-- ... 其他表单元素 ... -->
    <div class="form-row-child">
        <label for="month">Month</label>
        <select class="form-select" aria-label="Default select example" name="month" id="month">
            <option selected disabled>Select Month</option>
            <option value="January">January</option>
            <option value="February">February</option>
            <option value="March">March</option>
            <!-- ... 其他月份 ... -->
            <option value="December">December</option>
        </select>
    </div>
    <!-- ... 其他表单元素 ... -->
    <input type="submit" class="btn btn-danger form1-btn" value="Proceed">
</form>

<?php
// form2.php

// 1. 从 form1.php 获取月份数据
$selectedMonth = '';
if (isset($_POST['month'])) {
    $selectedMonth = $_POST['month'];
    // 可以在这里对 $selectedMonth 进行任何必要的处理或验证
}

// ... form2.php 的其他业务逻辑和数据处理 ...

// 假设这里有一些处理后的数据需要传递给 form3.php
// 例如：
$vagueEmployee = new stdClass(); // 示例对象
$vagueEmployee->setBasePay(50000);
$vagueEmployee->setWorkingHours(160);
$salaryPerHour = 312.5;
$payFor13thMonth = 4166.67;

?>
<!-- form2.php -->
<form action="form3.php" method="post">
    <!-- ... form2.php 的其他表单元素 ... -->

    <!-- 关键：添加隐藏字段以传递月份数据 -->
    <input type="hidden" name="month" value="<?php echo htmlspecialchars($selectedMonth); ?>">

    <!-- 传递其他处理后的数据 -->
    <input type="hidden" name="basePay" value="<?php echo htmlspecialchars($vagueEmployee->getBasePay()); ?>">
    <input type="hidden" name="workingHours" value="<?php echo htmlspecialchars($vagueEmployee->getWorkingHours()); ?>">
    <input type="hidden" name="salaryPerHour" value="<?php echo htmlspecialchars($salaryPerHour); ?>">
    <input type="hidden" name="payFor13thMonth" value="<?php echo htmlspecialchars($payFor13thMonth); ?>">

    <!-- ... form2.php 的其他表单元素 ... -->
    <input type="submit" class="btn btn-danger form1-btn" value="Proceed">
</form>

<?php
// form3.php

// 接收 form2.php 提交的所有数据，包括隐藏字段中的月份
$selectedMonth = '';
if (isset($_POST['month'])) {
    $selectedMonth = $_POST['month'];
}

// 接收其他数据
$payAfterAdditions = 60000; // 示例数据
$philhealth = 1500;
$sss = 2000;
$totalDeductions = $philhealth + $sss;
$taxableSalary = $payAfterAdditions - $totalDeductions;
$finalTax = $taxableSalary * 0.85; // 示例税率
$totalAbsences = 0; // 示例数据
$basePay = isset($_POST['basePay']) ? $_POST['basePay'] : 0; // 从隐藏字段获取

?>
<!-- form3.php -->
<main class="main">
    <div class="form-title">
        <p class="display-6">Employee Salary</p>
    </div>

    <div class="">
        <p>Selected Month: <?php echo htmlspecialchars($selectedMonth); ?></p> <!-- 显示月份 -->
        <p>Pay after additions: Php <?php echo htmlspecialchars($payAfterAdditions); ?></p>
        <p>Deductions</p>
        <p>Philhealth: Php <?php echo htmlspecialchars($philhealth); ?></p>
        <p>SSS: Php <?php echo htmlspecialchars($sss); ?></p>
        <p>Total deductions: Php <?php echo htmlspecialchars($totalDeductions); ?></p>
        <p>Taxable Salary: Php <?php echo htmlspecialchars($taxableSalary); ?></p>
        <p>Final Salary: Php <?php echo htmlspecialchars($finalTax); ?></p>
        <!-- lalabas lang kapag december -->
        <p>13 month pay: </p>
        <p> <?php echo htmlspecialchars($totalAbsences); ?></p>
        <p> <?php echo htmlspecialchars($basePay); ?></p>
    </div>
</main>