Laravel multiple files (save all or fail all ) - php

Question

I am making a form that create service with multiple images, I'm not sure if I am doing right saving process that handle failures.
for example if I have 5 images and already uploaded 3 but failed in the 4th image so I need to cancel saving process and delete all saved files.
$validatedImages = [];
foreach($images as $key => $image){
$imageName = ServiceImage::generateRecordName($image);
if(!$image->storeAs(ServiceImage::path(), $imageName)) {
// fall back all the stored files
foreach($validatedImages as $validatedImage)
Storage::delete(ServiceImage::path() . $validatedImage);
return redirect()->back()->with(['errorMsg' => 'There was a problem when uploading images']);
}
$validatedImages[] = $imageName;
}
and also when storing into database
foreach($validatedImages as $validatedImage)
if(!$service->images()->save(new ServiceImage(['name' => $validatedImage])))
// handle failure ..
so my question is : What is the best practice to handle this fall back.

Answer 1

Your controller should only be receiving fully-validated data. So those images should be ready for uploading once you’re in the body of your controller method:
$paths = [];
foreach ($request->file('images') as $image) {
$paths[] = $image->store('images');
}
// Do something with $paths
You probably want to upload images asynchronously. Especially if there are five of them in a request. With this approach, you can upload the files to a folder that is periodically cleaned (say after 24 hours). When an image is uploaded to this folder, return the paths. Submit the paths to your controller action instead of the actual files, and you can then move the files from the temporary folder to a permanent one.

Answer 2

Your method can be improved since what I see from your code is that, once you upload your files all you do is delete the file and again in another loop check for database upload. Since when all file is properly uploaded but could not be written in the database then you are deleting all those files again. This may not matter for small files but when files are large in size and the number of files are also large then this can cause unnecessary performance issues. for example you upload 100 files each of 10 mb size then you uploaded 1000mb but your file execution in database show error on the first database update then the upload of the remaining 99 files just goes in vain. Moreover, You are making four loops 2 for upload and 2 for database I see some unnecessary extra loop here. The loops can be reduced from 4 to 2 with this code and you can stop the script once a file has errors without going to another file and thus saving traffic and improving performance.
The key is you upload each file and write it to database and stop the script as soon as there is error either in the upload or database code execution success,
this is how i suggest you can improve the code.
$validatedImages = [];
foreach($images as $key => $image){
$imageName = ServiceImage::generateRecordName($image);
if(!$image->storeAs(ServiceImage::path(), $imageName)) {
$this->deleteImage($validatedImages);
return redirect()->back()->with(['errorMsg' => 'There was a problem when uploading images']);
}
if(!$service->images()->save(new ServiceImage(['name' => $imageName]))){
/*file has been uploaded but database error was found so this file needs to be deleted, */
$this->deleteImage($validatedImages,$imageName);
return redirect()->back()->with(['errorMsg' => 'There was a problem updating the database']);
}
$validatedImages[] = $imageName;
}
function deleteImage($validatedImages,$extraimage=null){
foreach($validatedImages as $validatedImage){
Storage::delete(ServiceImage::path() . $validatedImage);
//code for reversing database change
}
if($extraimage)
/*the image which was uploaded but could not be written in the
database*/
Storage::delete(ServiceImage::path() . $extraimage);
}
another method you can do is store the image in a temporary folder and move the file permanently only when all files get uploaded and once any error occurs you delete all the files in that temporary directory without deleting them in a loop.