FunWithFlags.Store.Persistent behaviour (fun_with_flags v1.6.0) View Source

A behaviour module for implementing persistence adapters.

The package ships with peristence adapters for Redis and Ecto, but you can provide your own adapters by adopting this behaviour.

Link to this section Summary

Callbacks

Retrieves all the names of the persisted flags.

Retrieves all the persisted flags.

Deletes an entire flag, identified by name.

Deletes a gate from a flag, identified by name.

Retrieves a flag by name.

Persists a gate for a flag, identified by name.

A persistent adapter should return either a child specification if it needs any process to be started and supervised, or nil if it does not.

Link to this section Callbacks

Specs

all_flag_names() :: {:ok, [atom()]}

Retrieves all the names of the persisted flags.

Specs

all_flags() :: {:ok, [FunWithFlags.Flag.t()]}

Retrieves all the persisted flags.

Specs

delete(flag_name :: atom()) :: {:ok, FunWithFlags.Flag.t()} | {:error, any()}

Deletes an entire flag, identified by name.

Specs

delete(flag_name :: atom(), gate :: FunWithFlags.Gate.t()) ::
  {:ok, FunWithFlags.Flag.t()} | {:error, any()}

Deletes a gate from a flag, identified by name.

Specs

get(flag_name :: atom()) :: {:ok, FunWithFlags.Flag.t()}

Retrieves a flag by name.

Specs

put(flag_name :: atom(), gate :: FunWithFlags.Gate.t()) ::
  {:ok, FunWithFlags.Flag.t()} | {:error, any()}

Persists a gate for a flag, identified by name.

Specs

worker_spec() :: Supervisor.child_spec() | nil

A persistent adapter should return either a child specification if it needs any process to be started and supervised, or nil if it does not.

For example, the builtin Redis persistence adapter implements this function by delegating to Redix.child_spec/1 because it needs the Redix processes to work. On the other hand, the builtin Ecto adapter implements this function by returning nil, because the Ecto repo is provided to this package by the host application, and it's assumed that the Ecto process tree is started and supervised somewhere else.

This custom worker_spec/0 function is used instead of the typical child_spec/1 function because this function can return nil if the adapter doesn't need to be supervised, whereas child_spec/1 must return a valid child spec map.