codeigniter 表单验证 - 只需要填写一个字段

Question

我在 codeigniter 中有一个表单，它有几个字段，但只需要有效填写一个。

<label for="mail_everyone">Mass Email</label>
<label><input type="checkbox" name="mail_everyone" id="mail_everyone" value="1" <?php echo set_checkbox('mail_everyone', '1'); ?>/> Send to everyone</label>
<?php echo form_error('mail_everyone'); ?>

<label for="mail_class_list">Class Email</label>
<select name="mail_class_list" id="mail_class_list">
    <option value="0">- Select -</option>
    <?php foreach($filter_classes as $class) : ?>
    <option value = "<?=$class['class_id']?>" <?php echo set_select('mail_class_list', $class['class_id'], ('class'==$mail_type&&$class['class_id']==$mail_type_id));?>><?=$class['class_code']?></option>
    <?php endforeach; ?>
</select>
<?php echo form_error('mail_class_list'); ?>

<label for="mail_mailing_list">Mailing List Email</label>
<select name="mail_mailing_list" id="mail_mailing_list">
    <option value="0"> - Select - </option>
    <?php foreach($mailing_lists as $list){ ?>
    <option value="<?=$list['mailer_list_id']?>" <?php echo set_select('mail_mailing_list', $list['mailer_list_id'], ('mailer.list'==$mail_type&&$list['mailer_list_id']==$mail_type_id));?>><?=$list['name']?></option>
    <?php } ?>
</select>
<?php echo form_error('mail_mailing_list'); ?>

然后我有验证码：

$this->form_validation->_error_array = array(); // Multiform reset
$this->form_validation->_field_data = array(); // Multiform reset
$this->form_validation->set_error_delimiters('<div class="error">', '</div>');

if ($this->form_validation->run() === false || isset($errors) && count($errors) > 0) {
    $errors[] = validation_errors('<div>', '</div>');
    $data['result'] = '<div class="error">' . implode('', $errors) . '</div>';
    $this->session->set_flashdata('result', $data['result']);
} else {
    // Check if a field has been filled in
    if(
        (!$this->input->post('mail_everyone') || 0 == set_value('mail_everyone')) &&
        0 == set_value('mail_class_list') &&
        0 == set_value('mail_performance_list') &&
        0 == set_value('mail_mailing_list') &&
        0 == set_value('mail_filter_list')
    ) {
        //No filters have been set
        $errors[] = validation_errors('<div>', '</div>');
        $errors[] = '<div>No valid mail type has been selected</div>';
        $data['result'] = '<div class="error">' . implode('', $errors) . '</div>';
        $this->session->set_flashdata('result', $data['result']);
    }

    $data['result'] = '<div class="success">Inserted : <em>' . $this->settings->format_datetime() . '</em></div>';
    $this->session->set_flashdata('result', $data['result']);
}

我需要让表单只需要填写一个字段。目前我检查验证，然后检查是否填写了任何字段，但是这段代码不起作用。这是我第一次深入研究 codeigniter，文档对我帮助不大。

Answer 1

我发现这些字段以字符串的形式返回，并且“0”而不是 0，所以：

"0" == set_value('mail_filter_list')