Current section

Files

Jump to
phoenix_live_view lib phoenix_live_view debug.ex
Raw

lib/phoenix_live_view/debug.ex

defmodule Phoenix.LiveView.Debug do
@moduledoc """
Functions for runtime introspection and debugging of LiveViews.
This module provides utilities for inspecting and debugging LiveView processes
at runtime. It allows you to:
* List all currently connected LiveViews
* Check if a process is a LiveView
* Get the socket of a LiveView process
* Inspect LiveComponents rendered in a LiveView
## Examples
# List all LiveViews
iex> Phoenix.LiveView.Debug.list_liveviews()
[%{pid: #PID<0.123.0>, view: MyAppWeb.PostLive.Index, topic: "lv:12345678", transport_pid: #PID<0.122.0>}]
# Check if a process is a LiveView
iex> Phoenix.LiveView.Debug.liveview_process?(pid(0,123,0))
true
# Get the socket of a LiveView process
iex> Phoenix.LiveView.Debug.socket(pid(0,123,0))
{:ok, %Phoenix.LiveView.Socket{...}}
# Get information about LiveComponents
iex> Phoenix.LiveView.Debug.live_components(pid(0,123,0))
{:ok, [%{id: "component-1", module: MyAppWeb.PostLive.Index.Component1, ...}]}
"""
@doc """
Returns a list of all currently connected LiveView processes (on the current node).
Each entry is a map with the following keys:
- `pid`: The PID of the LiveView process.
- `view`: The module of the LiveView.
- `topic`: The topic of the LiveView's channel.
- `transport_pid`: The PID of the transport process.
The `transport_pid` can be used to group LiveViews on the same page.
## Examples
iex> list_liveviews()
[%{pid: #PID<0.123.0>, view: MyAppWeb.PostLive.Index, topic: "lv:12345678", transport_pid: #PID<0.122.0>}]
"""
def list_liveviews do
for pid <- Process.list(), dict = lv_process_dict(pid), not is_nil(dict) do
{Phoenix.LiveView, view, topic} = keyfind(dict, :"$process_label")
%{pid: pid, view: view, topic: topic, transport_pid: keyfind(dict, :"$phx_transport_pid")}
end
end
defp keyfind(list, key) do
case List.keyfind(list, key, 0) do
{^key, value} -> value
_ -> nil
end
end
defp lv_process_dict(pid) do
# LiveViews set the "$process_label" to {Phoenix.LiveView, view, topic}
with info when is_list(info) <- Process.info(pid, [:dictionary]),
dictionary when not is_nil(dictionary) <- keyfind(info, :dictionary),
label when not is_nil(label) <- keyfind(dictionary, :"$process_label"),
{Phoenix.LiveView, view, topic} when is_atom(view) and is_binary(topic) <- label do
dictionary
else
_ -> nil
end
end
@doc """
Checks if the given pid is a LiveView process.
## Examples
iex> list_liveviews() |> Enum.at(0) |> Map.fetch!(:pid) |> liveview_process?()
true
iex> liveview_process?(pid(0,456,0))
false
"""
def liveview_process?(pid) do
not is_nil(lv_process_dict(pid))
end
@doc """
Returns the socket of the LiveView process.
## Examples
iex> list_liveviews() |> Enum.at(0) |> Map.fetch!(:pid) |> socket()
{:ok, %Phoenix.LiveView.Socket{...}}
iex> socket(pid(0,123,0))
{:error, :not_alive_or_not_a_liveview}
"""
def socket(liveview_pid) do
GenServer.call(liveview_pid, {:phoenix, :debug_get_socket})
catch
:exit, _ -> {:error, :not_alive_or_not_a_liveview}
end
@doc """
Returns a list with information about all LiveComponents rendered in the LiveView.
## Examples
iex> live_components(pid)
{:ok,
[
%{
id: "component-1",
module: MyAppWeb.PostLive.Index.Component1,
cid: 1,
assigns: %{
id: "component-1",
__changed__: %{},
flash: %{},
myself: %Phoenix.LiveComponent.CID{cid: 1},
...
}
}
]}
"""
def live_components(liveview_pid) do
GenServer.call(liveview_pid, {:phoenix, :debug_live_components})
catch
:exit, _ -> {:error, :not_alive_or_not_a_liveview}
end
end