View Source Nostrum.Cache.PresenceCache behaviour (Nostrum v0.6.1)
Cache behaviour & dispatcher for Discord presences.
By default, Elixir.Nostrum.Cache.PresenceCache.ETS will be use for caching
presences. You can override this in the :caches option of the nostrum
application by setting the :presences fields to a different module
implementing the Nostrum.Cache.PresenceCache behaviour. Any module below
Nostrum.Cache.PresenceCache implements this behaviour and can be used as a
cache.
Writing your own presence cache
As with the other caches, the presence cache API consists of two parts:
The functions that the user calls, currently only
get/2.The functions that nostrum calls, such as
create/1orupdate/1. These do not create any objects in the Discord API, they are purely created to update the cached data from data that Discord sends us. If you want to create objects on Discord, use the functions exposed byNostrum.Apiinstead.
You need to implement both of them for nostrum to work with your custom
cache. You also need to implement Supervisor callbacks, which will
start your cache as a child under Nostrum.Cache.CacheSupervisor: As an
example, the Nostrum.Cache.PresenceCache.ETS implementation uses this to to
set up its ETS table it uses for caching. See the callbacks section for every
nostrum-related callback you need to implement.
Link to this section Summary
Types
Represents a presence as received from Discord. See Presence Update.
Callbacks
Bulk create multiple presences for the given guild in the cache.
Create a presence in the cache.
Retrieves a presence for a user from the cache by guild and id.
Update the given presence in the cache from upstream data.
Functions
Same as get/1, but raise Nostrum.Error.CacheError in case of a failure.
Link to this section Types
Specs
presence()
Represents a presence as received from Discord. See Presence Update.
Link to this section Callbacks
Specs
bulk_create(Nostrum.Struct.Guild.id(), [presence()]) :: :ok
Bulk create multiple presences for the given guild in the cache.
Specs
create(presence()) :: :ok
Create a presence in the cache.
Specs
get(Nostrum.Struct.User.id(), Nostrum.Struct.Guild.id()) :: {:ok, presence()} | {:error, :presence_not_found}
Retrieves a presence for a user from the cache by guild and id.
If successful, returns {:ok, presence}. Otherwise returns {:error, reason}.
Example
case Nostrum.Cache.PresenceCache.get(111133335555, 222244446666) do
{:ok, presence} ->
"They're #{presence.status}"
{:error, _reason} ->
"They're dead Jim"
endSpecs
update(map()) :: {Nostrum.Struct.Guild.id(), old_presence :: presence() | nil, new_presence :: presence()} | :noop
Update the given presence in the cache from upstream data.
Return value
Return the guild ID along with the old presence (if it was cached, otherwise
nil) and the updated presence structure. If the :activities or :status
fields of the presence did not change, return :noop.
Link to this section Functions
Specs
get!(Nostrum.Struct.User.id(), Nostrum.Struct.Guild.id()) :: presence() | no_return()
Same as get/1, but raise Nostrum.Error.CacheError in case of a failure.