Ease new actions development and integration

[Benjamin Kampmann]

Currently a developer has to hack the different activities to make them support his new action.

We need a way to plug actions to activities or uris much easier.

[Florian Boucault (fboucault)]

Related work is ongoing and this ticket is just too vague.

[Benjamin Kampmann (benjamin-fluendo)]

well.

WE decided together(!!!) in a meeting that that's a problem and I should open that ticket. It was so vague, because we didn't have any idea how/what to make.

But if it is to vague for you, here you get an example:
If there is a developer, who makes an action to be able to rate an audio-file, we should be able to display it in the menu or to make it accessable for the user. Because we don't know _all_ actions that might come or could be activitated by the user, we need a generic way to do this (like we have a generic way to access metadata without knowing all the metadata providers).

That is still valid!

[Florian Boucault (fboucault)]

That is a use-case. We now need more of them. Also, there is no need to get over-excited.

[Benjamin Kampmann (benjamin-fluendo)]

more usecases? Okay:

 * an action for ripping audiocd-tracks to mp3/ogg/flac
 * an action for making an ISO of any cd/dvd inserted
 * an action to download stage6-movies (or other extern data) to the local system
 * an action to add something to favorite-data (like my favorites movies) or
 * an action love/hate to rate media
 * an action to find similar songs (related to #577)
 * an action to send a uri (for e.g. a stage6 or youtube one) to another elisa (for e.g. using a jabber service or pidgin over dbus)
 * an action to eject an audiocd (like we have for videodvd)
 * an action to upload images to flickr (or something)
 * an action to upload videos to stage6/youtube or something
 * an action to add tags to media (or to sort it into categories or both)
 * an action to display metadata of a media (like exif) and/or
 * an action to edit metadata (and write it to the file)
 * an action to transfer media to another elisa system (not the uri only) or to transfer it using jabber/pidigin (over dbus)
 * an action to select a (special) cover or poster for audio or video media

to be continued... (if you want to have)

A lot of them can be done by external or free developers, the only thing we need is a generic, smart and easy possibility to integrate them into elisa without changing the code...

[Philippe Normand (philn)]

Here's a plan to make it happen. Currently the actions are created by the media_menu_activity.

- In menu_activity we should add the ability for the activity to create an action component given its path (plugin:component_name). Let's name that method: _create_action(path) for instance.
- in media_menu_activity config we can add 2 options:

  * directory_actions: list of strings indicating action paths
  * file_actions: list of strings indicating action paths

- media_menu_activity would use these options, call _create_action for each value of the lists, create menu_models and insert them at the correct places in the menu tree.
- we would need to add additional data (such as the menu label) to the actions

[Philippe Normand (philn)]

The above plan doesn't solve all use-cases obviously. Example:"an action for ripping audiocd-tracks to mp3/ogg/flac". For this kind of thing we can provide some API addition in media_provider:

- get_directory_actions(directory_uri): returns list of action paths
- get_file_actions(file_uri): returns list of action paths

The activity would then be able to use that new API to on-the-file create new actions depending of the uri scheme and/or uri "type" (file/directory).

[Florian Boucault (fboucault)]

To sum up a little, actions should be able to access to launch any kind of task which may or may not have a UI.

[Florian Boucault (fboucault)]

It is not possible currently because Actions have access only to the controller which calls it.

Also, Actions should probably not be assigned to a model instance but rather in the controller layer:

- models would be more reusable

- it would probably waste less memory

- it would provide more flexibility

[Florian Boucault (fboucault)]

Postponing. Raising priority and severity.