php - 联系表格 7 - 自定义验证

Question

我只需要验证一个字段(称为“实例”)以仅接受小写 ASCII 字母和数字，第一个字符也必须是字母而不是数字。它将接受大写字符，但我们需要它在输入时将它们小写。因此，如果有人使用实例名称 McDonalds，它将被小写为 mcdonalds(不只是使用 CSS)。也不允许有空格。

这在 CF7 中可行吗？如果是，请解释如何。

我已经试过了 this自定义验证方法，但即使在文件中使用预设的自定义验证，它也只是显示字段简码而不是字段本身。

谢谢

Answer 1

来自 contactform7.com 自定义验证 → 作为过滤器验证:

In Contact Form 7, a user-input validation is implemented as a filter function. The filter hook used for the validation varies depending on the type of form-tag and is determined as: wpcf7_validate_ + {type of the form-tag}. So, for text form-tags, the filter hook wpcf7_validate_text is used. Likewise, wpcf7_validate_email* is used for email* form-tags.

Let’s say you have the following email fields in a form:

  Email:         [email* your-email]
  Confirm email: [email* your-email-confirm]

The following listing shows code that verifies whether the two fields have identical values.

add_filter('wpcf7_validate_email*', 'custom_email_confirmation_validation_filter', 20, 2);

function custom_email_confirmation_validation_filter($result, $tag) {
    $tag = new WPCF7_FormTag($tag);

    if ('your-email-confirm' == $tag->name) {
        $your_email = isset($_POST['your-email']) ? trim($_POST['your-email']) : '';
        $your_email_confirm = isset($_POST['your-email-confirm']) ? trim($_POST['your-email-confirm']) : '';

        if ($your_email != $your_email_confirm) {
            $result->invalidate($tag, "Are you sure this is the correct address?");
        }
    }
    return $result;
}

Two parameters will be passed to the filter function: $result and $tag. $result is an instance of WPCF7_Validation class that manages a sequence of validation processes. $tag is an associative array composed of given form-tag components; as you saw in the previous recipe, you can use WPCF7_FormTag class to handle this type of data.

Look through the inside of the filter function. First, check the name of the form-tag to ensure the validation is applied only to the specific field (your-email-confirm).

The two email field values are then compared, and if they don’t match, $result->invalidate() will be called. You need to pass two parameters to the invalidate() method: the first parameter should be the $tag variable, and the second parameter is the validation error message that you want the field to display.

Lastly, don’t forget to return the $result.