Use PSR-4 and public API

[PVince81]

Port this to use the public API for registering the backend.
Goal is to make it work without files_external once owncloud/core#25422 is done.

[mention-bot]

@PVince81, thanks for your PR! By analyzing the annotation information on this pull request, we identified @icewind1991 and @DeepDiver1975 to be potential reviewers

[PVince81]

@DeepDiver1975 can you help with with PSR-4 ? For some reason it can't find the Application class:

{"reqId":"PCg7VpZKMMKaNhz5RNf+","remoteAddr":"127.0.0.1","app":"PHP","message":"Class 'OCA\\Files_External_Ftp\\AppInfo\\Application' not found at \/srv\/www\/htdocs\/owncloud\/apps3\/files_external_ftp\/appinfo\/app.php#3","level":3,"time":"2016-09-14T09:33:34+00:00","method":"GET","url":"\/owncloud\/index.php\/settings\/admin","user":"admin"}

[PVince81]

Never mind... the namespace must be "Files_external_ftp"

[PVince81]

Note: the setting "username" has to be renamed to "user" to match what the password auth delivers, do we need a migration ?

[DeepDiver1975]

Note: the setting "username" has to be renamed to "user" to match what the password auth delivers, do we need a migration ?

I'd say yes ...

[PVince81]

Bäh... I switched it back to "built-in" so we don't have to provide a migration yet.

What I did though is also adjust the namespaces to work against the new core-based external storage API. So this PR requires owncloud/core#25422 to work. And it also works if the "files_external" app is disabled on that branch.

[PVince81]

The core PR was merged, rebased.

[DeepDiver1975]

👍