如何在 Codeigniter 3 中上传时显示不允许的文件类型错误消息？

我正在做一个基本的工作博客应用程序 https://github.com/Ajax30/lightblog with 代码点火器 3.1.8 and 引导程序4.

当然，这些帖子有主要图片。有一个默认图像如果用户没有上传图像，但是如果有图像is已上传，有仅允许 3 种类型：jpg、jpeg 和 png。

为了警告用户以防她/他尝试上传其他文件格式，我在Posts控制器：

// Upload image
$config['upload_path'] = './assets/img/posts';
$config['allowed_types'] = 'jpg|jpeg|png';
$config['max_size'] = '2048';

$this->load->library('upload', $config);

if(!$this->upload->do_upload()){

    $data['uerrors'] = $this->upload->display_errors();

    if ($data['uerrors']) {
        $this->load->view('partials/header', $data);
        $this->load->view('dashboard/create-post');
        $this->load->view('partials/footer');
    } else {
        $post_image = 'default.jpg';
    }

} else {
    $data = array('upload_data' => $this->upload->data());
    $post_image = $_FILES['userfile']['name'];
}

在我看来：

<?php foreach ($uerrors as $uerror): ?>
  <span><?php echo $uerror; ?></span>
<?php endforeach; ?>

然而，我得到了未定义的变量：uerrors error.

这是整个create() method:

public function create() {

    // Only logged in users can create posts
    if (!$this->session->userdata('is_logged_in')) {
        redirect('login');
    }

    $data = $this->get_data();
    $data['tagline'] = "Add New Post";

    if ($data['categories']) {
        foreach ($data['categories'] as &$category) {
            $category->posts_count = $this->Posts_model->count_posts_in_category($category->id);
        }
    }

    $this->form_validation->set_rules('title', 'Title', 'required');
    $this->form_validation->set_rules('desc', 'Short description', 'required');
    $this->form_validation->set_rules('body', 'Body', 'required');
    $this->form_validation->set_error_delimiters('<p class="error-message">', '</p>');

    if($this->form_validation->run() === FALSE){
        $this->load->view('partials/header', $data);
        $this->load->view('dashboard/create-post');
        $this->load->view('partials/footer');
    } else {
        // Create slug (from title)
        $slug = url_title(convert_accented_characters($this->input->post('title')), 'dash', TRUE);
        $slugcount = $this->Posts_model->slug_count($slug, null);
        if ($slugcount > 0) {
            $slug = $slug."-".$slugcount;
        }

        // Upload image
        $config['upload_path'] = './assets/img/posts';
        $config['allowed_types'] = 'jpg|jpeg|png';
        $config['max_size'] = '2048';

        $this->load->library('upload', $config);

        if(!$this->upload->do_upload()){

            $data['uerrors'] = $this->upload->display_errors();

            if ($data['uerrors']) {
                $this->load->view('partials/header', $data);
                $this->load->view('dashboard/create-post');
                $this->load->view('partials/footer');
            } else {
                $post_image = 'default.jpg';
            }

        } else {
            $data = array('upload_data' => $this->upload->data());
            $post_image = $_FILES['userfile']['name'];
        }

        $this->Posts_model->create_post($post_image, $slug);
        $this->session->set_flashdata('post_created', 'Your post has been created');
        redirect('/');
    }
} 

我的错误在哪里？

您的上传代码看起来没问题，但您需要更新以下更改。

1. 将数据传递给您的'dashboard/create-post'查看您已通过的'partials/header'看法。你的'dashboard/create-post'view 没有收到任何上传错误消息，所以它说'Undefined variable: uerrors'。所以，你的上传代码应该是这样的 -

if(!$this->upload->do_upload()){
    $data['uerrors'] = $this->upload->display_errors();
    if ($data['uerrors']) {
        $this->load->view('partials/header', $data);
        $this->load->view('dashboard/create-post', $data);
        $this->load->view('partials/footer');
    } else {
        $post_image = 'default.jpg';
    }
} else {
    $post_image = $this->upload->data('file_name');
}

2. As CodeIgniter 文档 https://codeigniter.com/user_guide/libraries/file_uploading.html#CI_Upload::display_errors说，“display_errors()”返回字符串，而不是数组，您不必循环遍历错误。只需在您的设备上回显即可'dashboard/create-post' view.

为了您的方便，请使用不同的方法创建上传任务，以便您也可以在更新方法中重复使用它。例如 -

private function uploadFile(){
    if ($_FILES['userfile']['name'] === '') {
        return array(
            'status' => TRUE,
            'message' => 'No file selected.',
            'file_name' => 'default.jpg'
        );
    }

    // Upload image
    $config['upload_path'] = './assets/img/posts';
    $config['allowed_types'] = 'jpg|jpeg|png';
    $config['max_size'] = '2048';

    $this->load->library('upload', $config);

    if(!$this->upload->do_upload('userfile')){
        return array(
            'status' => FALSE,
            'message' => $this->upload->display_errors('<p class="text-danger ">', '</p>'),
            'file_name' => ''
        );
    }else{
        return array(
            'status' => TRUE,
            'message' => 'File uploaded successfully',
            'file_name' => $this->upload->data('file_name')
        );
    }
}

那么你的整个创建方法应该是这样的 -

public function create() {
    // Only logged in users can create posts
    if (!$this->session->userdata('is_logged_in')) {
        redirect('login');
    }

    $data = $this->get_data();
    $data['tagline'] = "Add New Post";

    if ($data['categories']) {
        foreach ($data['categories'] as &$category) {
            $category->posts_count = $this->Posts_model->count_posts_in_category($category->id);
        }
    }

    $this->form_validation->set_rules('title', 'Title', 'required');
    $this->form_validation->set_rules('desc', 'Short description', 'required');
    $this->form_validation->set_rules('body', 'Body', 'required');
    $this->form_validation->set_error_delimiters('<p class="error-message">', '</p>');

    if($this->form_validation->run() === FALSE){
        $this->load->view('partials/header', $data);
        $this->load->view('dashboard/create-post');
        $this->load->view('partials/footer');
    } else {
        $upload = $this->uploadFile();

        if($upload['status'] === FALSE){
            $data['upload_error'] = $upload['message'];

            $this->load->view('partials/header', $data);
            $this->load->view('dashboard/create-post', $data);
            $this->load->view('partials/footer');
        }else{
            // Create slug (from title)
            $slug = url_title(convert_accented_characters($this->input->post('title')), 'dash', TRUE);
            $slugcount = $this->Posts_model->slug_count($slug, null);
            if ($slugcount > 0) {
                $slug = $slug."-".$slugcount;
            }

            $this->Posts_model->create_post($upload['file_name'], $slug);
            $this->session->set_flashdata('post_created', 'Your post has been created');
            redirect('/');
        }
    }
}

最后将这行代码添加到您的'dashboard/create-post'查看文件，位于文件输入按钮之后。

<?php if(isset($upload_error)) echo $upload_error; ?>

我认为一切都应该有效。