Creating a temp folder is also done with "Open With Application" extension. And this can be cleanded automatically or manually at any time when Opera is open.

Thanks for the change. The button is a very good solution.

I am writing an extension where I need a response to start an action when the body of a notification is clicked and another action when the cancel cross is clicked. In the old native notification that is still available in Opera 34 when disabling libnotify this works as preferred. In Opera 35 now this disable option is no longer available and I have to use the libnotify notification system in Debian 9 with KDE 5. Here, the response of the body click of the notification behaves similar to the cancel click. Does anyone has an idea to find a difference for programming this?

Well, I guess this is a security reason not to give more permission to system settings through a web browser. In my opinion it is an understandable solution. But what I wrote might be an opertunity to come a bit closer by using an addon.

Do you mean to change a torrent mime type to a user defined mime type? Operas file association is defined in the system (Windows, Linux, Mac-OS-X) setting. Then you just need to specify a certain program to open it. But what exactly is the benefit from that? I can only think of following advantage:
If you define different mime type variants for one specific mime type you could open a downloaded file with the application of choice in a pop-up dialog window. Is this what you think of?

Example (Let's use the example of the torrent file):
The normal mime type for torrents is: "application/x-bittorrent"
Before downloading the file it is possible to change the mime type in the header for example to: "application/x-bittorrent-utorrent" which could be opened with uTorrent. Instead of "-utorrent" you could choose whatever you want and specify the related torrent application to that.
In a dialog box you could choose the program of choice before the change in the header. But all this can only be useful if you also add those specific mime types to your system setting with an associated application.

I am currently doing a big modification to the abovementioned addon. Maybe several ideas can be implemented there, too.

I wrote an extension to come close to the old open behaviour. You can find this one here: https://addons.opera.com/en-gb/extensions/details/open-with-application/?display=en

Creating a temp folder is also done with "Open With Application" extension. And this can be cleanded automatically or manually at any time when Opera is open.

Well, there are some annoying behaviours in Opera for now. There are a couple of files that are - without any other choice opened directly in Opera, f.e. mp4, txt. To be sure to save a file you should choose Rightclick + "Save linked Content As ...". Then there are files that are definitly saved. I do not know what works better for you. My idea would be to use Rightclick + "Save linked Content As ..." to save a file and left mouse click to open it.
Maybe you also have an idea what behaviour you would like to have and I try my best to change the extension.

Hello. See this thread:
https://forums.opera.com/post/80478

Regarding download or open files I had exactly the same problem with the new Opera first, so I decided to start writing this little extension. First exercise was to find a way around the multiple necessary clicks until a file can be opened especially you are doing some investigation using a lot of pdf files. My final decision was to use a system notification that informs when a download is finished and what to do next - open or cancel. System notification from the chromium api are not fully supported in Opera so there are only those two possible options at the moment. "Open" opens the file in the system defined application. The file is then stored in "temporary_downloads" folder in the default download folder. "Cancel" deletes the temporary download instantly. Furthermore you can check an option to always clean up the "temporary_downloads" folder at Opera startup. You can choose defined file types or add your own file types.

Here is the link:
https://addons.opera.com/en-gb/extensions/details/open-with-application/?display=en

I would be glad if you could try out this addon and give me some feedback telling me what you might wish for this extension.

Hello everyone. I found this thread luckily without knowing, that someone linked my addon to you guys. I had exactly the same problem with the new Opera first, so I decided to start writing this little extension. First exercise was to find a way around the multiple necessary clicks until a file can be opened especially you are doing some investigation using a lot of pdf files. My final decision was to use a system notification that informs when a download is finished and what to do next - open or cancel. System notification from the chromium api are not fully supported in Opera so there are only those two possible options at the moment. "Open" opens the file in the system defined application. The file is then stored in "temporary_downloads" folder in the default download folder. "Cancel" deletes the temporary download instantly. Furthermore you can check an option to always clean up the "temporary_downloads" folder at Opera startup. You can choose defined file types or add your own file types.

I would be glad if you could try out this addon and give me some feedback telling me what you might wish for this extension.