In today's Internet environment, the security and user experience of websites are always the focus of operators.Especially in the face of increasingly fierce automated attacks and spam, the captcha mechanism has become an indispensable defense line.However, a poorly designed captcha system not only fails to effectively prevent malicious behavior, but may also become an obstacle to user experience.In such an efficient and flexible content management system as AnQiCMS, how to ingeniously integrate and update captcha images dynamically in templates to balance security and smooth user experience is a concern for many developers and operators.

As an experienced website operation expert, I am well aware that the strength of Anqi CMS lies in its high-performance architecture based on Go language and the ease of use of Django template engine like features.It allows us to build rich and responsive websites through concise labels and coherent logic.srcProperty, it is a typical scenario to give full play to its template advantages.

Understanding the necessity of dynamic captcha

Firstly, we need to understand why captcha images need to be dynamically updated.Placing a fixed captcha image on the page is meaningless, as malicious programs can easily recognize and submit preset captchas.NewandUnique

Overview of Anqi CMS captcha mechanism

The captcha mechanism of Anqi CMS is designed to be very intuitive and efficient. It is mainly divided into two parts:

  1. Backend support:The administrator can enable the captcha feature in the background. Safe CMS will automatically generate captcha images and their corresponding unique IDs, and expose them through a standard API interface.
  2. Front-end Integration:A developer places one in the template<img>A tag to display the captcha, one hidden<input>Field used to store the captcha ID, as well as a text box for users to input the captcha.Through JavaScript, the front end can send requests to the back-end API to obtain a new verification code image URL and ID, and update the page elements in real time.

Next, we will elaborate on how to implement this dynamic update process in the security CMS template.

Step 1: Enable the captcha feature in the background.

To ensure that the captcha function can be used normally, you first need to enable it in the admin interface of the Security CMS.tag-/anqiapi-other/167.htmlThe guidance of the document, you need to log in to the backend, find the area related to content or plugin settings.通常，这会在“后台设置”下的“内容设置”或“功能管理”中找到类似“留言评论验证码功能”的选项。Check and save this setting, and the backend of Safe CMS will prepare the captcha service for frontend requests.

第二步：In the front-end template, integrate the captcha element with dynamic logic

In your security CMS template, it is usually the areas that require captcha, such as message forms, registration forms, or comment sections, where you need to add some HTML elements and JavaScript code.

The first is the HTML structure. You need a<img>tag to display the captcha image, a hiddeninputfield to store the unique identifier of each generated captcha, and a normalinputField for user to input verification code. For example, you can lay it out like this in your form:

<div class="form-group captcha-group">
  <label for="captcha-input">验证码</label>
  <div class="captcha-wrapper">
    <!-- 用于存储验证码ID的隐藏字段，非常重要！ -->
    <input type="hidden" name="captcha_id" id="captcha_id">
    <!-- 用于显示验证码图片，设定一个ID以便JavaScript操作 -->
    <img src="" id="get-captcha" alt="验证码" style="width: 150px; height: 56px; cursor: pointer; border: 1px solid #ccc; vertical-align: middle;" />
    <!-- 用户输入验证码的文本框 -->
    <input type="text" name="captcha" id="captcha-input" required placeholder="请输入验证码" class="form-control" style="width: 120px; display: inline-block; margin-left: 10px;" />
  </div>
</div>

Please note,<img>TagssrcThe property can initially be an empty string because it will be dynamically loaded via JavaScript.id="get-captcha"andid="captcha_id"is the key to locating these elements in JavaScript. At the same time, in order to enhance the user experience, it can be indicated that the image can be clicked to refresh.<img>Label addcursor: pointer;The style hints that the image can be clicked to refresh.

Next, is the core implementation of dynamically obtaining and updating the captcha——JavaScript code.This code is usually placed at the bottom of the page, or executed after the document is loaded.

<script>
  // 确保DOM内容加载完毕后再执行
  document.addEventListener('DOMContentLoaded', function() {
    const captchaImage = document.getElementById('get-captcha');
    const captchaIdInput = document.getElementById('captcha_id');

    // 定义获取并更新验证码的函数
    function fetchNewCaptcha() {
      fetch('/api/captcha') // 向安企CMS的验证码API发送请求
        .then(response => response.json()) // 将响应解析为JSON格式
        .then(data => {
          if (data && data.data) {
            // 更新隐藏字段的captcha_id
            captchaIdInput.value = data.data.captcha_id;
            // 更新验证码图片的src属性，显示新图片
            captchaImage.src = data.data.captcha;
          } else {
            console.error('获取验证码失败:', data);
            // 可以在此处显示错误信息给用户
          }
        })
        .catch(error => {
          console.error('网络请求错误:', error);
          // 可以在此处提示用户网络问题
        });
    }

    // 页面加载完成后立即请求一次验证码
    fetchNewCaptcha();

    // 绑定点击事件，当用户点击验证码图片时，重新加载验证码
    captchaImage.addEventListener('click', fetchNewCaptcha);
  });
</script>

If you are accustomed to using jQuery, you can also achieve the same logic in a more concise way:

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/jquery.min.js"></script>
<script>
  $(document).ready(function() {
    const $captchaImage = $('#get-captcha');
    const $captchaIdInput = $('#captcha_id');

    function fetchNewCaptcha() {
      $.get('/api/captcha', function(res) {
        if (res && res.data) {
          $captchaIdInput.val(res.data.captcha_id);
          $captchaImage.attr('src', res.data.captcha);
        } else {
          console.error('获取验证码失败:', res);
        }
      }).fail(function(jqXHR, textStatus, errorThrown) {
        console.error('网络请求错误:', textStatus, errorThrown);
      });
    }

    // 页面加载和点击图片时都调用
    fetchNewCaptcha();
    $captchaImage.on('click', fetchNewCaptcha);
  });
</script>

In this JavaScript code, we did several key things:

  • fetch('/api/captcha')or$.get('/api/captcha')This is the API endpoint for sending a request to the Anqi CMS backend to retrieve a new verification code. Anqi CMS will return a response containingcaptcha_id(The unique identifier of the captcha) andcaptchaThe JSON object of the (captcha image URL).
  • captchaIdInput.value = data.data.captcha_id;: Assign to thecaptcha_idhiddeninputfield. When the user submits the form, thiscaptcha_idThe captcha will be sent to the backend along with the user's input for verification.
  • captchaImage.src = data.data.captcha;Assigns the captcha image URL returned by the backend to<img>Tagssrcproperty, so that the new captcha image can be displayed on the page.
  • fetchNewCaptcha();In the page loading completed, execute once immediatelyfetchNewCaptchaFunction, ensure the captcha is displayed as soon as the page is initially loaded.
  • captchaImage.addEventListener('click', fetchNewCaptcha);or$captchaImage.on('click', fetchNewCaptcha);To add a click event listener to the captcha image, the image will be reloaded each time it is clickedfetchNewCaptchafunction to refresh the captcha.

Summary

By following these two simple and crucial steps, you will be able to achieve dynamic retrieval and updating of captcha images in the security CMS template.This method not only ensures the security of the website, effectively resists the intrusion of automated programs, but also provides a more flexible and user-friendly user experience through the click refresh mechanism.AnQi CMS, with its powerful functions and flexible customization, makes the integration of such security mechanisms extremely convenient, allowing operators to focus more on the content itself rather than the tedious technical details.

Common Questions (FAQ)

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