@spec animate(Enumerable.t() | pos_integer(), (term() -> any())) :: nothing()

Renders a kino that periodically calls the given function to render a new result.

The callback receives a stream element and should return a term to be rendered.

This function uses Kino.Frame as the underlying kino. It returns nothing (a non-printable result).

Examples

An animation is created by turning a stream of values into subsequent animation frames:

Stream.interval(100)
|> Stream.take(100)
|> Kino.animate(fn i ->
  Kino.Markdown.new("**Iteration: `#{i}`**")
end)

Alternatively an integer may be passed as a shorthand for Stream.interval/1:

# Render new Markdown every 100ms
Kino.animate(100, fn i ->
  Kino.Markdown.new("**Iteration: `#{i}`**")
end)

@spec animate(
  Enumerable.t() | pos_integer(),
  state,
  (term(), state -> {:cont, term(), state} | :halt)
) :: nothing()
when state: term()

A stateful version of animate/2.

The callback receives a stream element and the accumulated state and it should return either of:

• {:cont, term_to_render, state} - the continue

• :halt - to no longer schedule callback evaluation

Examples

This function is primarily useful to consume Kino.Control events:

button = Kino.Control.button("Click")

button
|> Kino.Control.stream()
|> Kino.animate(0, fn _event, counter ->
  new_counter = counter + 1
  md = Kino.Markdown.new("**Clicks: `#{new_counter}`**")
  {:cont, md, new_counter}
end)

@spec async_listen(Enumerable.t() | pos_integer(), (term() -> any())) :: pid()

Same as listen/2, except each event is processed concurrently.

@spec beam_paths() :: [String.t()]

Returns the directories that contain .beam files for modules defined in the notebook.

@spec configure(keyword()) :: :ok

Configures Kino.

The supported options are:

• :inspect

They are discussed individually in the sections below.

Inspect

A keyword list containing inspect options used for printing usual evaluation results. Defaults to pretty formatting with a limit of 50 entries.

To show more entries, you configure a higher limit:

Kino.configure(inspect: [limit: 200])

You can also show all entries by setting the limit to :infinity, but keep in mind that for large data structures it is memory-expensive and is not an advised configuration in this case. Instead prefer the use of IO.inspect/2 with :infinity limit when needed.

See Inspect.Opts for the full list of options.

@spec inspect(
  term(),
  keyword()
) :: term()

Inspects the given term as cell output.

This works essentially the same as IO.inspect/2, except it always produces colored text and respects the configuration set with configure/1.

Opposite to render/1, it does not attempt to render the given term as a kino.

@spec interrupt!(:normal | :error, String.t()) :: no_return()

Interrupts evaluation with the given message.

This function raises a specific error to let Livebook known that evaluation should be stopped. The error message and a Continue button are shown to the user, who can then attempt to resolve the source of the interrupt before resuming execution.

Do not use interrupt inside listeners

Since interrupt!/2 aborts the execution, it cannot be used inside Kino.listen/2 or other event listeners. In such cases, you can use Kino.Frame and render any messages directly within the frame, using Kino.Text or Kino.Markdown.

Examples

text =
  Kino.Input.text("Input")
  |> Kino.render()
  |> Kino.Input.read()

if text == "" do
  Kino.interrupt!(:error, "Input required")
end

# This will not be run if the `interrupt!` is called above
Kino.Markdown.new("**You entered:** #{text}")

@spec listen(Enumerable.t() | pos_integer(), (term() -> any())) :: pid()

Starts a process that consumes a stream with fun without blocking execution.

It returns the PID of the started process. The process can be terminated with Kino.terminate_child/1.

Note that events are processed by fun sequentially. If you want to process them concurrently, use async_listen/2.

Examples

This function is primarily useful to consume Kino.Control events:

Kino.Control.button("Greet")
|> Kino.listen(fn event -> IO.inspect(event) end)

You can also merge multiple controls into a single stream. For example, in order to merge them and tag each with a distinct event:

button = Kino.Control.button("Hello")
input = Kino.Input.checkbox("Check")

stream = Kino.Control.tagged_stream([hello: button, check: input])

Kino.listen(stream, fn
  {:hello, event} -> ...
  {:check, event} -> ...
end)

Any other stream works as well:

Stream.interval(100)
|> Stream.take(10)
|> Kino.listen(fn i -> IO.puts("Ping #{i}") end)

Finally, an integer may be passed as a shorthand for Stream.interval/1:

Kino.listen(100, fn i -> IO.puts("Ping #{i}") end)

@spec listen(
  Enumerable.t() | pos_integer(),
  state,
  (term(), state -> {:cont, state} | :halt)
) :: pid()
when state: term()

A stateful version of listen/2.

The callback should return either of:

• {:cont, state} - the continue

• :halt - to stop listening

Examples

button = Kino.Control.button("Click")

Kino.listen(button, 0, fn _event, counter ->
  new_counter = counter + 1
  IO.puts("Clicks: #{new_counter}")
  {:cont, new_counter}
end)

@spec nothing() :: nothing()

Returns a special value that results in no visible output.

Examples

This is especially handy when you wish to suppress the default output of a cell. For instance, a cell containing this would normally result in verbose response output:

resp = Req.get!("https://example.org")

That output can be suppressed by appending a call to nothing/0:

resp = Req.get!("https://example.org")
Kino.nothing()

@spec recompile() :: :ok

Recompiles dependenies.

Once you have installed dependencies with Mix.install/1, this will recompile any outdated path dependencies declared during the install.

Reproducability

Keep in mind that recompiling dependency modules is not going to mark any cells as stale. This means that the given notebook state may no longer be reproducable. This function is meant as a utility when prototyping alongside a Mix project.

@spec render(term()) :: term()

Renders the given term as cell output.

This effectively allows any Livebook cell to have multiple evaluation results.

@spec start_child(Supervisor.child_spec() | {module(), term()} | module()) ::
  DynamicSupervisor.on_start_child()

Starts a process under the Kino supervisor.

The process is automatically terminated when the current process terminates or the current cell reevaluates.

If you want to terminate the started process, use terminate_child/1. If you terminate the process manually, the Kino supervisor might restart it if the child's :restart strategy says so.

Nested start

It is not possible to use start_child/1 while initializing another process started this way. In other words, you generally cannot call start_child/1 inside callbacks such as GenServer.init/1 or Kino.JS.Live.init/2. If you do that, starting the process will block forever.

On creation, many kinos use start_child/1 underneath, which means that you cannot use functions such as Kino.DataTable.new/1 in GenServer.init/1. If you need to do that, you must either create the kinos beforehand and pass in the GenServer argument, or create them in GenServer.handle_continue/2.

@spec start_child!(Supervisor.child_spec() | {module(), term()} | module()) :: pid()

Similar to start_child/2 but returns the new pid or raises an error.

@spec terminate_child(pid()) :: :ok | {:error, :not_found}

Terminates a child started with start_child/1.

Returns :ok if the child was found and terminated, or {:error, :not_found} if the child was not found.

@spec tmp_dir() :: String.t() | nil

Returns a temporary directory that gets removed when the runtime terminates.