在 Codeigniter 3 中上传时如何显示不允许的文件类型错误消息？

Question

我正在使用 Codeigniter 3.1.8 和 Bootstrap 4 开发基本的 blog application。

这些帖子当然有主要图片。如果用户没有上传图片，则有一个默认图片，但如果上传图片，则只允许三种类型：jpg , jpeg 和 png。

想要警告用户以防她/他尝试上传其他文件格式，我在 Posts 控制器中执行了此操作：

// 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，我得到一个 Undefined variable: uerrors 错误。

这是整个create()方法：

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？

Answer 1

此错误告诉您变量不存在或未初始化。看这段代码

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

if ($data['uerrors']) {

我认为您可能在某处（未在此代码中显示）有一个未初始化的 $uerrors 变量。请注意，我不相信array 索引'uerrors' 会在上面的块中给您带来麻烦，因为首先您定义它，其次，如果您引用不存在的array 项目，那么您将收到与问题中引用的不同的错误消息。

Answer 2

你的问题有点含糊。无论如何，设置变量$uerrors 的唯一条件是何时执行create() 方法，我相信该方法将在POST 请求中执行。此外，您没有提到这是视图的哪一部分：

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

如果是dashboard/create-post 视图，则尝试将$data 直接传递给该视图，而不是将其传递给partials/header

注意：我刚刚检查了 codeigniter View/Controller samples，发现使用 isset() 函数调用检查变量是一个好习惯，因此不要直接执行 foreach 循环，而是这样做：

<? if (isset($uerrors)): ?>
    <? foreach ($uerrors as $uerror): ?>
      <span><?= $uerror; ?></span>
    <? endforeach; ?> 
<? endif; ?> 

Answer 3

您的上传代码看起来不错，但您需要更新以下更改。

1. 将数据传递给'dashboard/create-post' 视图，就像您传递给'partials/header' 视图一样。您的'dashboard/create-post' 视图没有收到任何上传错误消息，因此它显示的是'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');
}

1. 正如CodeIgniter Documentation 所说，'display_errors()' 返回字符串，而不是数组，您不必遍历错误。只需在您的 'dashboard/create-post' 视图中回显即可。

为了您的方便，请以不同的方法制作您的上传任务，以便您也可以在更新方法中重复使用它。举个例子-

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 create 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('/');
        }
    }
}

最后在你的'dashboard/create-post'视图文件中添加这行代码，就在文件输入按钮之后。

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

我认为一切都应该工作。

Answer 4

您需要将 $data['uerrors'] 初始化为 null，因为您在前端使用它

$data['uerrors'] = '';

或者检查前端的值不为空。

前端，你可以这样做：

<?php  if (isset($uerrors) && $uerrors != '') {
            foreach ($uerrors as $uerror) {
                echo '<span>' . $uerror . '</span>';
            }
        } ?>

您的控制器将是：

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

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

        /*You need to initialize  $data['uerrors'] as null because you are using it on front end*/
        $data['uerrors'] = '';
        if (!$this->upload->do_upload('FilePath')) {
            $data['uerrors'] = $this->upload->display_errors();
            $this->load->view('partials/header', $data);
            $this->load->view('dashboard/create-post');
            $this->load->view('partials/footer');
        } else {
            if (isset($_POST{'your_file'})) {
                /*'check your images here that you are receiving from front end'*/
            } else {
                /*If there is no image, then default image is*/
                $post_image = 'default.jpg';
            }
            $data = array('upload_data' => $this->upload->data());
            $post_image = $_FILES['userfile']['name'];
        }

您可以在How to upload image in CodeIgniter?上进一步找到有用的帖子

Answer 5

我在这里捡到了三样东西

1) 如前所述，没有将 $data 传递给正确的视图

2) 在视图中期望数组而不是字符串，即错误的数据类型

3) 最后，函数 do_upload() 需要参数字符串 $field。缺少这就是为什么您只有 no upload selected 错误。如果设置了这个参数，codeigniter 真的会抛出错误的文件类型错误。我这样做是为了测试

在我看来

<form action="http://localhost:8000/welcome/create" method="post" enctype="multipart/form-data">
          <input type="file" name="lname" ><br>
          <input type="submit" value="Submit">
        </form>

然后在我的控制器中

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

上传错误的文件类型以测试此错误。您可能需要额外的长度来检测实际上传文件的文件类型。

Answer 6

通过这样修改create()，我已经成功显示上传错误（如果尝试上传，否则使用默认图片）：

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()){

            $errors = array('error' => $this->upload->display_errors());

            // Display upload validation errors 
            // only if a file is uploaded and there are errors
            if (empty($_FILES['userfile']['name'])) {
                $errors = [];
            }

            if (empty($errors)) {
                $post_image = 'default.jpg';
            } else {
                $data['upload_errors'] = $errors;
            }

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

        if (empty($errors)) {
            $this->Posts_model->create_post($post_image, $slug);
            $this->session->set_flashdata('post_created', 'Your post has been created');
            redirect('/');
        } else {
            $this->load->view('partials/header', $data);
            $this->load->view('dashboard/create-post');
            $this->load->view('partials/footer');
        }
    }
}

在create-post.php 视图中我有：

<?php if(isset($upload_errors)){
   foreach ($upload_errors as $upload_error) {
    echo $upload_error;
   }
 }?>