如何阻止未填写表单时点击Next按钮跳转至下一页？

问题根源 #

当前代码中，「Next」按钮被包裹在<a>标签内，点击会直接触发页面跳转，完全绕过了表单校验逻辑；同时下拉选择框未设置必填规则，输入框的required属性也因按钮类型不是提交按钮而无法生效。

修改后的完整代码 #

HTML（含校验逻辑）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="styleform.css">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css">
    <script src="https://kit.fontawesome.com/f5ba79b0f3.js" crossorigin="anonymous"></script>
    <title>Kitchen Owner's Package</title>
</head>

<body>
  <div class="container">
    <div class="title">Fill the Form</div>
    <div class="content">
      <form id="kitchenForm" onsubmit="return handleFormSubmit()">
        <div class="user-details">
          <div class="input-box">
            <span class="details">Kitchen Owner's Name</span>
            <input type="text" placeholder="Enter your name" required>
          </div>

          <div class="input-box">
            <span class="details">Cloud Kitchen Name</span>
            <input type="text" placeholder="Enter your kitchen name" required>
          </div>

          <div class="input-box">
            <span class="details">Choose a package</span>
            <select id="package" name="package" required>
              <option value="" title="select">Please choose a package from the below list:</option>
              <option value="onemonth">Monthly  @5,000/- BDT</option>
              <option value="sixmonths">Half-Yearly  @25,000/- BDT</option>
              <option value="twelvemonths">Yearly  @50,000/- BDT</option>
            </select>
          </div>

          <div class="input-box">
            <span class="details">Payment Method</span>
            <select id="paymentMethod" name="paymentMethod" required>
              <option value="" title="select">Pay Through:</option>
              <option value="bkash">Bkash</option>
            </select>
          </div>
        </div>
        
        <div class="button">
          <input type="submit" value="Next">
        </div>
      </form>
    </div>
  </div>

  <script>
    function handleFormSubmit() {
      const form = document.getElementById('kitchenForm');
      // 调用HTML5内置校验
      if (form.checkValidity()) {
        // 执行原发送邮件逻辑（若有实现）
        sendEmail();
        // 校验通过后跳转
        window.location.href = 'payment.html';
        // 可选：重置表单
        form.reset();
        return false;
      } else {
        // 显示浏览器默认的校验提示
        form.reportValidity();
        return false;
      }
    }

    // 保留原sendEmail函数（需自行实现发送逻辑）
    function sendEmail() {
      // 此处编写邮件发送代码
    }
  </script>
</body>
</html>

CSS（保持原代码不变）

@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@200;300;400;500;600;700&display=swap");
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}
body {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  background: linear-gradient(135deg, #f1fb40, #f5fba3);
}
.container {
  max-width: 800px;
  width: 400%;
  background-color: #fff;
  padding: 25px 30px;
  border-radius: 5px;
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.15);
}
.container .title {
  font-size: 25px;
  font-weight: 500;
  position: relative;
}
.container .title::before {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 30px;
  border-radius: 5px;
  background: linear-gradient(135deg, #71b7e6, #9b59b6);
}
.content form .user-details {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  margin: 20px 0 12px 0;
}
form .user-details .input-box {
  margin-bottom: 15px;
  width: calc(100% / 2 - 20px);
}
form .input-box span.details {
  display: block;
  font-weight: 500;
  margin-bottom: 5px;
}
.user-details .input-box input {
  height: 40px;
  width: 100%;
  outline: none;
  font-size: 16px;
  border-radius: 5px;
  padding-left: 15px;
  border: 1px solid #ccc;
  border-bottom-width: 2px;
  transition: all 0.3s ease;
}
.user-details .input-box input:focus,
.user-details .input-box input:valid {
  border-color: #9b59b6;
}


form .button {
  width: 100px;
  height: 45px;
  border-radius: 10px;
  margin: 35px 0;
}

form .button input {
  height: 100%;
  width: 100%;
  border-radius: 5px;
  border: none;
  color: #fff;
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.3s ease;
  background: linear-gradient(135deg, #7469da, #c7a9d3);
}

form .button input:hover {
  background: linear-gradient(-135deg, #84b6da, #978b9c);
}
@media (max-width: 584px) {
  .container {
    max-width: 100%;
  }
  form .user-details .input-box {
    margin-bottom: 15px;
    width: 100%;
  }
  form .category {
    width: 100%;
  }
  .content form .user-details {
    max-height: 300px;
    overflow-y: scroll;
  }
  .user-details::-webkit-scrollbar {
    width: 5px;
  }
}
@media (max-width: 459px) {
  .container .content .category {
    flex-direction: column;
  }
}

关键改动说明 #

1. 重构按钮触发逻辑：移除包裹按钮的<a>标签，将按钮改为type="submit"，让它触发表单提交事件，而非直接跳转。
2. 完善下拉框校验规则：给两个<select>添加required属性，同时将默认选项的value设为空字符串，确保未选择时触发校验；修正重复的id属性（原两个下拉框都用package，改为paymentMethod避免冲突）。
3. 修复表单提交逻辑：修正onsubmit的语法错误，通过自定义函数handleFormSubmit控制校验与跳转流程。
4. 添加校验逻辑：利用HTML5内置的checkValidity()和reportValidity()方法，实现字段合法性检查，并在不合法时显示浏览器原生校验提示，阻止页面跳转。

内容的提问来源于stack exchange，提问作者Fardin Jim