I have created a chat app using live views in which whenever user joins a chatroom then all the messages of the chat room displayed to him that are saved in database and if some updates or edit any message it works perfect everyone sees the updated message but sometimes it misses some user screens specially if some leave a chat room open for few hours then the that user stops receiving updates and he need to refresh browser even sometimes browser refresh don’t work
Here is my code in my live view for chat
defmodule FchatappWeb.ChatLive do
use FchatappWeb, :live_view
alias Fchatapp.Blog
alias Fchatapp.Blog.Room
alias Fchatapp.Repo
alias Fchatapp.Chats.Message
import Ecto.Query, only: [from: 2]
@imp true
def mount(%{"room" => name}, session, socket) do
room_data = Repo.get_by(Room, title: name)
room_data_id = room_data.id
query =
from m in Message,
where: m.room_id == ^room_data_id
db_messages = Repo.all(query)
topic = "room:" <> name
email =
case session["current_user"] do
nil ->
"Anonymous User"
_ ->
session["current_user"].email
end
anonymous_user =
case email do
"Anonymous User" ->
true
_ ->
false
end
if connected?(socket) do
Process.send_after(self(), %{event: "update", room_id: room_data_id}, 5000)
FchatappWeb.Endpoint.subscribe(topic)
FchatappWeb.Presence.track(self(), topic, email, %{})
end
{:ok,
assign(socket,
room: name,
room_id: room_data.id,
image: room_data.image_thumb_url,
country: room_data.country,
state: room_data.state,
city: room_data.city,
description: room_data.description,
topic: topic,
user: email,
anonymous_user: anonymous_user,
message: "",
image_public_id: "",
image_thumb_url: "",
image_url: "",
image_secure_url: "",
img_context: "",
messages: db_messages,
user_list: [],
temporary_assigns: [messages: []]
)}
end
@imp true
def handle_event(
"submit_message",
%{
"_csrf_token" => _token,
"chat" => %{
"message" => message,
"image_public_id" => image_public_id,
"image_thumb_url" => image_thumb_url,
"image_url" => image_url,
"image_secure_url" => image_secure_url,
"room_id" => room_id,
"img_context" => img_context
}
},
socket
) do
message = %{
uid: UUID.uuid4(),
content: message,
user: socket.assigns.user,
image_public_id: image_public_id,
image_thumb_url: image_thumb_url,
image_url: image_url,
image_secure_url: image_secure_url,
room_id: room_id,
img_context: img_context
}
case image_url do
"" ->
{:ok}
_ ->
resp =
HTTPoison.post(
"http://localhost:4000/api/create-message",
message |> Poison.encode!(),
%{"Content-Type" => "application/json"}
)
end
FchatappWeb.Endpoint.broadcast(socket.assigns.topic, "new-message", message)
{:noreply,
assign(socket,
message: "",
image_public_id: "",
image_thumb_url: "",
image_url: "",
image_secure_url: ""
)}
end
@imp true
def handle_event(
"form_update",
%{
"_csrf_token" => _token,
"chat" => %{
"message" => message,
"image_public_id" => image_public_id,
"image_thumb_url" => image_thumb_url,
"image_url" => image_url,
"image_secure_url" => image_secure_url,
"room_id" => room_id,
"img_context" => img_context
}
},
socket
) do
{:noreply,
assign(socket,
message: message,
image_public_id: image_public_id,
image_thumb_url: image_thumb_url,
image_url: image_url,
image_secure_url: image_secure_url,
room_id: room_id,
img_context: img_context
)}
end
@imp true
def handle_info(%{event: "new-message", payload: message}, socket) do
{:noreply, assign(socket, messages: [message])}
end
def handle_info(%{event: "update", room_id: id}, socket) do
Process.send_after(self(), %{event: "update", room_id: id}, 5000)
query =
from m in Message,
where: m.room_id == ^id
db_messages = Repo.all(query)
{:noreply, assign(socket, messages: db_messages)}
end
def handle_info(%{event: "presence_diff", payload: %{joins: joins, leaves: leaves}}, socket) do
join_messages =
joins
|> Map.keys()
|> Enum.map(fn username ->
%{uid: UUID.uuid4(), content: "#{username} Joined!", user: "System"}
end)
leave_messages =
leaves
|> Map.keys()
|> Enum.map(fn username ->
%{uid: UUID.uuid4(), content: "#{username} Left!", user: "System"}
end)
user_list =
FchatappWeb.Presence.list(socket.assigns.topic)
|> Map.keys()
{:noreply, assign(socket, user_list: user_list)}
end
def display_message(%{uid: id, content: content, user: "System"}) do
~E"""
<p id="<%= id %>"><em><%= content %></em></p>
"""
end
def display_message(
%{
uid: id,
content: content,
user: user,
image_public_id: image_public_id,
image_thumb_url: image_thumb_url,
image_url: image_url,
image_secure_url: image_secure_url
} = params
) do
case image_url do
"" ->
~E"""
<div id="<%= id %>">
<img src="https://media.istockphoto.com/vectors/emoticon-with-sorry-sign-vector-id1266144552?k=20&m=1266144552&s=170667a&w=0&h=m-3MDOgzYDjsynL729p7G8Pn98PNKLu345LnFwkcZlY=" width="100" height="150"></img>
<p><em>Image cant be empty</em></p>
</div>
"""
_ ->
~E"""
<div id="<%= id %>">
<div><img src="<%= image_url%>" width="100" height="150"></img>
<p><strong><%= user%>: </strong><%= content %> </p>
</div>
</div>
"""
end
end
end
Here is template hidden inputs are coming from an api
<section>
<div id="header-text">
<div id="title">
<p >Currently Chatting In <strong><%= @room %></strong></p>
<p ><img src="<%= @image %>" alt="no-image"></p>
<p ><%= @description %></p>
<button><a href="/">Leave Room</a></button>
</div>
</div>
<br>
<div id="main">
<div class="sub-main">
<div id="chat-container">
<div id="messages-container" phx-update="append">
<%= for message <- @messages do%>
<%= display_message(message) %>
<% end %>
</div>
</div>
<%= if @anonymous_user do %>
<p><strong><em>Please login to send messages</em></strong></p>
<% else %>
<div id="form-chat">
<%= f = form_for :chat, "#", id: "chat-form", phx_submit: :submit_message, phx_change: :form_update %>
<%= text_input f, :message, value: @message, placeholder: "Enter your message..." %>
<%= hidden_input f, :image_public_id, value: @image_public_id, id: "image_public_id" %>
<%= hidden_input f, :image_thumb_url, value: @image_thumb_url, id: "image_thumb_url" %>
<%= hidden_input f, :image_url, value: @image_url, id: "image_url" %>
<%= hidden_input f, :image_secure_url, value: @image_secure_url, id: "image_secure_url" %>
<%= hidden_input f, :room_id, value: @room_id, id: "room_id" %>
<%= hidden_input f, :img_context, value: @img_context, id: "img_context" %>
<!-- placeholder for uploaded image -->
<img
id="uploadedimage"
src="<%= @image_thumb_url %>">
</img>
<button
id="upload_widget"
class="cloudinary-button" type="button">
Upload New Image
</button>
</form>
</div>
<% end %>
</div>
<div id="users">
<h3>
Online User
</h3>
<%= for user <- @user_list do%>
<p><%= user %></p>
<% end %>
</div>
</div>
</section>
Thanks in advance
