Summary:
This diff addresses two problems:
1. Since clients plugins can be active beyond having a connection, we have to make it possible for plugin authors to check if they are connected before they make a call.
2. if there is a custom `exportPersistedState`, plugins should be able to skip making calls if the device has disconnected.
Introducing this change makes it possible to interact with a reasonable level with disconnected clients, and makes it possible to create Flipper traces for disconnected clients.
Note that both items were already problems before supporting offline clients; as there can be a noticeable delay between disconnecting and Flipper detecting that (i've seen up to 30 secs). What happend previously in those cases is that the export would simply hang, as would other user interactions, as loosing the connection in the middle of a process would cause the promise chains to be neither rejected or resolved, which is pretty iffy.
Before this diff, trying to export a disconnected device would hang forever like:
{F369600601}
Reviewed By: nikoant
Differential Revision: D26250895
fbshipit-source-id: 177624a116883c3cba14390cd0fe164e243bb97c
flipper-plugin
flipper-plugin is the dependency used by all modern Flipper plugins (project "Tommy").
For background: https://fb.quip.com/YHOGAnaPqAVJ
flipper-plugin is to be used as dev and peer dependency of all Flipper plugins. It provides:
- (TODO) Standard API's to interact with Flipper, such as the client connection.
- (TODO) Standard components to organize the UI
- (TODO) Testing utilities
API's provided by flipper-plugin are documented at fbflipper.com (TODO).
There should normally be no need to install flipper-plugin as dependency.
Rather, plugins should be scaffolded using npx flipper-pkg init (TODO) as documented here