How to Create a Basic PubSub Application - Revision history

Admin at 18:31, 1 September 2025

2025-09-01T18:31:53Z

← Older revision		Revision as of 18:31, 1 September 2025
Line 102:		Line 102:

	end		end
			</source>


			<source>
			# lib/app/counter.ex
			defmodule Counter do
			use Agent

			def start_link(initial_value) do
			Agent.start_link(fn -> initial_value end, name: __MODULE__)
			end

			def value do
			Agent.get(__MODULE__, & &1)
			end

			def increment do
			Agent.update(__MODULE__, &(&1 + 1))
			end
			end


			# lib/app_web/live/page_live.ex
			defmodule AppWeb.PageLive do
			use AppWeb, :live_view

			def mount(_params, _session, socket) do
			Phoenix.PubSub.subscribe(App.PubSub, "the-topic")

			# Get current value from the supervised Counter
			data = Counter.value()

			{:ok, assign(socket, data: data)}
			end

			def handle_event("increment", _params, socket) do
			Counter.increment()
			new_data = Counter.value()
			Phoenix.PubSub.broadcast(App.PubSub, "the-topic", new_data)
			{:noreply, assign(socket, data: new_data)}
			end

			def handle_info(new_data_from_broadcast, socket) do # usually set with pattern match like {:data,thedata}
			IO.inspect new_data_from_broadcast
			{:noreply, assign(socket, data: new_data_from_broadcast)}
			end



			def render(assigns) do
			~H"""
			<div>
			<.button phx-click="increment">click me </.button>

			<div>{@data}</div>
			</div>
			"""
			end
			end

	</source>		</source>

2023-06-16T04:16:37Z

@@ Line 47: / Line 47: @@
      |> broadcast_change([:testbed, :created])
    end
 </source>

2023-06-15T01:46:27Z

← Older revision		Revision as of 01:46, 15 June 2023
Line 2:		Line 2:


	~~'''lib/app_name/application.ex'''~~



			==In LiveView ==

	<source>		<source>

	def ~~start~~(~~_type~~, ~~_args~~) do		def mount(_params, _session, socket) do
	~~children =~~ [		Testbeds.subscribe()
	~~# Start the Telemetry supervisor~~		{:ok, assign(socket, testbeds: Testbeds.list_testbeds())}
	~~AppWeb.Telemetry,~~		end
	~~# Start the Ecto repository~~
	App.~~Repo,~~
	~~# Start the PubSub system~~		def handle_info({TestBeds, [:testbed \| _], _}, socket) do
	{Phoenix.PubSub~~, name:~~ App.PubSub},		{:noreply, assign(socket, testbeds: TestBeds.list_testbeds())}
			end
			</source>

			== App/test_beds.ex ==
			<source>

			@topic inspect(__MODULE__)

			def subscribe do
			Phoenix.PubSub.subscribe(App.PubSub, @topic)
			end



	]		defp broadcast_change({:ok, result}, event) do
			Phoenix.PubSub.broadcast(App.PubSub, @topic, {__MODULE__, event, result})

	~~...~~		{:ok, result}
	end		end



			# ....

			def create_testbed(attrs \\ %{}) do
			%Testbed{}
			\|> Testbed.changeset(attrs)
			\|> Repo.insert()
			\|> broadcast_change([:testbed, :created])
			end
	</source>		</source>

2023-05-07T06:09:29Z

← Older revision		Revision as of 06:09, 7 May 2023
Line 1:		Line 1:
	{{In progress}}		{{In progress}}


			'''lib/app_name/application.ex'''


			<source>

			def start(_type, _args) do
			children = [
			# Start the Telemetry supervisor
			AppWeb.Telemetry,
			# Start the Ecto repository
			App.Repo,
			# Start the PubSub system
			{Phoenix.PubSub, name: App.PubSub},

			]

			...
			end
			</source>

2023-05-07T06:06:08Z

Created page with "{{In progress}}"

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