# LiveEvent

[](https://hex.pm/packages/live_event)
[](https://hexdocs.pm/live_event/)
[](https://github.com/schrockwell/live_event/blob/main/LICENSE)
LiveEvent adds a simple API to LiveViews and LiveComponents:
- `emit/3` to raise an event
- `handle_emit/4` to handle it
With these two functions, server-side event messages can be handled the same way by both LiveViews and LiveComponents, facilitating the easier design of flexible, reusable components.
Please see [the docs](https://hexdocs.pm/live_event/) for full documentation and examples.
## Usage
Imagine a LiveComponent that has an `:on_selected` event.
```elixir
# Raise an event from a LiveComponent
emit(socket, :on_selected, %{id: 123})
# Handle the event on a LiveView, OR another LiveComponent
def handle_emit(:on_selected, {MyComponent, "component-id"}, %{id: id}, socket), do: ...
```
To send component events to a LiveView, pass `self()` to the `:on_selected` assign.
To send component events to a LiveComponent, pass `{module, id}` to the `:on_selected` assign.
That's all there is to it.
## Example
```elixir
defmodule MyLiveComponent do
use Phoenix.LiveComponent
use LiveEvent.LiveComponent # <-- adds lifecycle hooks and imports
def render(assigns) do
~H"""
<button phx-click="click" phx-target={@myself}>Click me</button>
"""
end
def handle_event("click", _, socket) do
# use emit/3 to send events
{:noreply, emit(socket, :on_selected, %{at: DateTime.utc_now()})}
end
end
defmodule MyLiveView do
use Phoenix.LiveView
use LiveEvent.LiveView # <-- adds lifecycle hooks and imports
def render(assigns) do
~H"""
<.live_component module={MyLiveComponent} id="my-component" on_selected={self()} />
"""
end
# use handle_emit/4 to process events - it works on LiveViews AND LiveComponents
def handle_emit(:on_selected, {MyLiveComponent, "my-component"}, %{at: at}, socket) do
IO.puts("Selected at #{at}")
{:ok, socket}
end
end
```
## Installation
The package can be installed
by adding `live_event` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
# For LiveView 0.16.x and 0.17.x
{:live_event, "~> 0.2.0"}
# For LiveView 0.18.x and greater
{:live_event, "~> 0.3.0"}
]
end
```
For Phoenix projects, add the LiveEvent hooks to the `live_view` and `live_component` macros.
```elixir
# lib/my_app_web.ex
defmodule MyAppWeb do
def live_view do
quote do
use LiveEvent.LiveView
end
end
def live_component do
quote do
use LiveEvent.LiveComponent
end
end
end
```