Reference (Old Docs)
FBSDKMessengerURLHandlerOpenFromComposerContext
A more recent version of this class is available. Check out the latest version.

This object represents a user selecting this app from the composer in Messenger Passing this context into a share method will trigger a the reply flow

Superclass:FBSDKMessengerContext
Declared in:FBSDKMessengerURLHandlerOpenFromComposerContext.h
Properties
metadata

Additional information that was passed along with the original media

@property (nonatomic, copy, readonly) NSString *metadata;
Discussion:

Note that when opening your app from Messenger composer, the metadata is pulled from the most recent attributed message on the thread. If the most recent attributed message with metadata is not cached on the device, metadata will be nil

Declared In: FBSDKMessengerURLHandlerOpenFromComposerContext.h
userIDs

The user IDs of the other participants on the thread.

@property (nonatomic, copy, readonly) NSSet *userIDs;
Discussion:

User IDs can be used with the Facebook SDK and Graph API (https://developers.facebook.com/docs/graph-api) to query names, photos, and other data. This will only contain IDs of users that have also logged into your app via their Facebook account. Note that when opening your app from Messenger composer, the userIDs are pulled from the most recent attributed message on the thread. If the most recent attributed message is not cached on the device, userIDs will be nil

Declared In: FBSDKMessengerURLHandlerOpenFromComposerContext.h