Native platform effect requests.

Effects are asynchronous I/O operations that require the renderer to interact with the OS on behalf of the Elixir app -- file dialogs, clipboard access, notifications, and similar.

Each function takes an atom tag as the first argument and returns a Plushie.Command struct. Dispatch it from update/2 like any other command. The result arrives later as a %Plushie.Event.EffectEvent{tag: tag, result: result} event in update/2. Pattern match on the tag to identify which effect the response belongs to.

Only one effect per tag can be in flight at a time. Starting a new effect with a tag that already has a pending request discards the previous one.

Example

def update(model, %Plushie.Event.WidgetEvent{type: :click, id: "open"}) do
  {model, Plushie.Effect.file_open(:import, title: "Pick a file")}
end

def update(model, %Plushie.Event.EffectEvent{tag: :import, result: {:ok, %{path: path}}}) do
  %{model | file: path}
end

def update(model, %Plushie.Event.EffectEvent{tag: :import, result: :cancelled}) do
  model
end

Timeouts

Each effect has a default timeout. If the renderer does not respond in time, %Plushie.Event.EffectEvent{tag: tag, result: {:error, :timeout}} arrives in update/2.

Default timeouts:

• File dialogs (file_open, file_open_multiple, file_save, directory_select, directory_select_multiple): 120 seconds
• Clipboard operations: 5 seconds
• Notifications: 5 seconds

Override the default by passing a :timeout option (milliseconds):

Plushie.Effect.file_open(:import, title: "Pick a file", timeout: 300_000)