View Source Reactive (Reactive State v0.1.0)

Module to manage reactive state by using GenServer processes ("reactive process" from here on) to manage each piece of state and its relationships to other reactive processes

Installation

The package can be installed by adding reactive_state to your list of dependencies in mix.exs:

def deps do
  [
    {:reactive_state, "~> 0.1.0"}
  ]
end

Examples

Working with data directly with Reactive.Ref

iex> use Reactive
iex> ref = Ref.new(0) #PID<0.204.0>
iex> Ref.get(ref) # or Ref.get(ref)
0
iex> Ref.set(ref, 1)
:ok
iex> Ref.get(ref)
1

Reactive Block

iex> use Reactive
iex> ref = Ref.new(2)
iex> ref_squared = reactive do
...>   get(ref) ** 2
...> end
iex> Reactive.get(ref_squared)
4
iex> Ref.set(ref, 3)
iex> Reactive.get(ref_squared)
9

Conditional Branches

iex> use Reactive
iex> if_false = Ref.new(1)
iex> if_true = Ref.new(2)
iex> toggle = Ref.new(false)
iex> computed = reactive do
...>   if get(toggle) do
...>     get(if_true)
...>   else
...>     get(if_false)
...>   end
...> end
iex> Reactive.get(computed)
1
iex> Ref.set(toggle, true)
:ok
iex> Reactive.get(computed)
2
iex> # Now, updating `if_false` will not require a recomputation
iex> Ref.set(if_false, 0)
:ok
iex> Reactive.get_cached(computed)
2
iex> # Updating `if_true` will require a recomputation
iex> Ref.set(if_true, 3)
:ok
iex> Reactive.get_cached(computed)
:stale
iex> Reactive.get(computed)
3

Summary

Functions

Returns a specification to start this module under a supervisor.

Retrieve the state of a reactive process

Retrieve the state of a reactive process, and register the current process as dependent of that process, with the call ID of the current process. You should use the Reactive.reactive macro to manage reactive relationships instead

Retrieve the cached state of a reactive process, or :stale if it has not been computed or is stale

Create a reactive process using a method

Syntatic sugar for creating reactive blocks

Replace a reactive process's computation method

Functions

Returns a specification to start this module under a supervisor.

See Supervisor.

Retrieve the state of a reactive process

Example

iex> ref = Reactive.new(fn _ -> 0 end)
iex> Reactive.get(ref)
0

Retrieve the state of a reactive process, and register the current process as dependent of that process, with the call ID of the current process. You should use the Reactive.reactive macro to manage reactive relationships instead

Example

iex> use Reactive
iex> ref = reactive do
...>   0
...> end
iex> Reactive.get(ref)
0

Retrieve the cached state of a reactive process, or :stale if it has not been computed or is stale

Example

iex> use Reactive
iex> ref = reactive do
...>   0
...> end
iex> Reactive.get_cached(ref)
:stale
iex> Reactive.get(ref)
0
iex> Reactive.get_cached(ref)
0

Create a reactive process using a method

iex> use Reactive
iex> ref = Ref.new(2)
iex> ref_squared = Reactive.new(fn call_id ->
...>   Reactive.get(ref, call_id) ** 2
...> end)
iex> Reactive.get(ref_squared)
4

Syntatic sugar for creating reactive blocks

iex> use Reactive
iex> ref = Ref.new(2)
iex> ref_squared = reactive do
...>   get(ref) ** 2
...> end #PID<0.204.0>
iex> Reactive.get(ref_squared)
4
iex> Ref.set(ref, 3)
iex> Reactive.get(ref_squared)
9

Using the reactive macro in this way is roughly equivalent to:

iex> use Reactive
iex> ref = Ref.new(2)
iex> ref_squared = Reactive.new(fn call_id ->
...>   Reactive.get(ref, call_id) ** 2
...> end)
iex> Reactive.get(ref_squared)
4
iex> Ref.set(ref, 3)
iex> Reactive.get(ref_squared)
9

Replace a reactive process's computation method

iex> use Reactive
iex> ref = reactive do
...>   0
...> end
iex> Reactive.get(ref)
0
iex> Reactive.set(ref, fn _ -> 1 end)
:ok
iex> Reactive.get(ref)
1