File Uploading

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File Uploading in CodeIgniter (CodeIgniter 4)

CodeIgniter 4 provides a secure and flexible file upload system with built-in validation and file handling features.

1. Requirements for File Upload

• Form method must be POST

• Form enctype must be multipart/form-data

2. Upload Form (View)

<!-- app/Views/upload.php -->
<?= form_open_multipart('upload/save') ?>

Select Image
<input type="file" name="image">

<button type="submit">Upload</button>

<?= form_close() ?>

3. Upload Controller

class Upload extends BaseController
{
    public function save()
    {
        $file = $this->request->getFile('image');

        if (! $file->isValid()) {
            return redirect()->back()->with('error', 'Invalid file');
        }

        $file->move(WRITEPATH . 'uploads');

        return "File uploaded successfully";
    }
}

4. File Upload Validation

$rules = [
    'image' => [
        'rules' => 'uploaded[image]|max_size[image,1024]|is_image[image]',
        'errors' => [
            'uploaded' => 'Please choose a file',
            'max_size' => 'File size must be less than 1MB',
            'is_image' => 'Only images are allowed'
        ]
    ]
];

if (! $this->validate($rules)) {
    return redirect()->back()->withInput();
}

5. Upload with Custom File Name

$newName = $file->getRandomName();
$file->move(WRITEPATH . 'uploads', $newName);

6. Upload to Public Folder

$file->move(FCPATH . 'uploads');

Access:

http://localhost/uploads/filename.jpg

7. Multiple File Upload

View

<input type="file" name="images[]" multiple>

Controller

$files = $this->request->getFiles();

foreach ($files['images'] as $file) {
    if ($file->isValid()) {
        $file->move(WRITEPATH . 'uploads');
    }
}

8. Allowed File Types

$rules = [
    'file' => 'uploaded[file]|ext_in[file,pdf,doc,docx]'
];

9. Get File Info

$file->getName();        // Original name
$file->getClientMimeType();
$file->getSize();

10. Delete Uploaded File

unlink(WRITEPATH . 'uploads/' . $filename);

11. Security Best Practices

✅ Validate file type & size
✅ Use random file names
✅ Store uploads outside public if possible
❌ Never trust file extension alone

Summary

• CodeIgniter supports secure file uploads

• Built-in validation rules

• Supports single & multiple uploads

• Easy integration with forms & controllers