Debounce (debounce v1.0.0) View Source

A process-based debouncer for Elixir.

What is a debouncer?

A debouncer is responsible for calling a function with a delay, but if that function is called multiple times within the delay period, the time is reset and delay is counted again. In other words, the function will be called after a delay period has elapsed from the last application.

Each time, the debounced function is called, a new task is started.

Example

iex> {:ok, pid} = Debounce.start_link({Kernel, :send, [self(), "Hello"]}, 100)
iex> Debounce.apply(pid)  # Schedules call in 100 ms
iex> :timer.sleep(50)
iex> Debounce.apply(pid)  # Resets timer back to 100 ms
iex> :timer.sleep(100)
iex> receive do msg -> msg end
"Hello"                   # Timer elapsed
iex> Debounce.apply(pid)  # Schedules call in 100 ms
iex> Debounce.cancel(pid) # Cancels scheduled call
:ok

Link to this section Summary

Types

apply()

debouncer()

mfargs()

option()

time()

Functions

apply(debouncer, args \\ [])

Schedules call to the current debouncer's function.

cancel(debouncer)

Cancels any scheduled call to the current debouncer's function.

change_function(debouncer, new_function)

Changes the function the debouncer is applying.

change_timeout(debouncer, new_timeout)

Changes the delay the debouncer operates with.

flush(debouncer, args)

Immediately invokes the current debouncer's function.

start(apply, timeout, opts \\ [])

Starts a Debounce process without links (outside of a supervision tree).

start_link(apply, timeout, opts \\ [])

Starts a Debounce process linked to the current process.

stop(debouncer, reason \\ :normal, timeout \\ :infinity)

Synchronously stops the debouncer with the given reason.

Link to this section Types

apply()

Specs

apply() :: (() -> term()) | mfargs()

debouncer()

Specs

debouncer() :: :gen_statem.server_ref()

mfargs()

Specs

mfargs() :: {module(), atom(), [term()]}

option()

Specs

option() :: {:name, GenServer.name()} | :gen_statem.start_opt()

time()

Specs

time() :: non_neg_integer()

Link to this section Functions

apply(debouncer, args \\ [])

Specs

apply(debouncer(), [term()]) :: :ok

Schedules call to the current debouncer's function.

If the function is a fun, calls it with provided args. If the function is an mfargs/0 tuple, appends provided args to the original ones.

If this function is called again withing the current debouncer's timeout value, the time will reset.

cancel(debouncer)

Specs

cancel(debouncer()) :: :ok

Cancels any scheduled call to the current debouncer's function.

change_function(debouncer, new_function)

Specs

change_function(debouncer(), apply()) :: :ok

Changes the function the debouncer is applying.

Affects only future calls to apply/2.

change_timeout(debouncer, new_timeout)

Specs

change_timeout(debouncer(), time()) :: :ok

Changes the delay the debouncer operates with.

Affects only future calls to apply/2.

flush(debouncer, args)

Specs

flush(debouncer(), [term()]) :: :ok

Immediately invokes the current debouncer's function.

If the function is a fun, calls it with provided args. If the function is an mfargs/0 tuple, appends provided args to the original ones.

start(apply, timeout, opts \\ [])

Specs

start(apply(), time(), [option()]) :: :gen_statem.start_ret()

Starts a Debounce process without links (outside of a supervision tree).

See start_link/3 for more information.

start_link(apply, timeout, opts \\ [])

Specs

start_link(apply(), time(), [option()]) :: :gen_statem.start_ret()

Starts a Debounce process linked to the current process.

This can be used to start the Debounce as part of a supervision tree.

Delays invoking apply until after timeout millisecnds have elapsed since the last time the apply/2 function was called.

Options

:name- used for name registration, like in GenServer.start_link/3.
all other options supported by :gen_statem.start_link/4

stop(debouncer, reason \\ :normal, timeout \\ :infinity)

Specs

stop(debouncer(), reason :: term(), timeout()) :: :ok

Synchronously stops the debouncer with the given reason.