fixed messages when leaving and changing name

srcs/requirements/svelte/api_front/src/pieces/chat/Layout_home.svelte

@@ -1,13 +1,18 @@
-<script>
+<script lang="ts">
 
 	import { layout, msgs, user, current_room } from './Store_chat';
 	import { change_room, get_room_messages, get_my_rooms } from './Request_rooms';
 	import { to_print } from './Utils_chat';
 	import { onMount } from 'svelte';
 	import Button from './Element_button.svelte';
+	import type { FetchResponse } from './Types_chat';
+	import Warning from './Element_warning.svelte';
 
 	let rooms = get_my_rooms();
 
+	let response: FetchResponse;
+	let show_error = false;
+
 	// go to clicked room
 	async function go_to_room(room)
 	{
@@ -21,8 +26,11 @@
 		}
 		else
 		{
-			await change_room(room);
-			await get_room_messages();
+			response = await change_room(room);
+
+			// print error message
+			if (response.status >= 300 || response.error)
+				show_error = response.error;
 		}
 	}
 
@@ -47,6 +55,9 @@
 
 	<!-- panel home -->
 	<div class="panel panel_home __border_top">
+		{#if show_error}
+			<Warning content={response.message}/>
+		{/if}
 		<p class="title">list of your rooms :</p>
 		<div class="room_list">
 			<div class="__show_if_only_child">

srcs/requirements/svelte/api_front/src/pieces/chat/Request_rooms.ts

@@ -45,13 +45,16 @@ export async function join_room(room: Room)
 	return response.room;
 }
 
-export async function change_room(room: Room)
+export async function change_room(room: Room): Promise<FetchResponse>
 {
 	to_print("in change_room");
 
 	to_print("room sent to change:", room);
 	let response: FetchResponse = await fetch_chat_request('change', FetchMethod.POST, room);
-	to_print("room returned from change:", response.room);
+	to_print("room returned from change:", response);
+
+	if (response.status >= 300 || response.error)
+		return response;
 
 	await get_room_messages();
 
@@ -59,6 +62,8 @@ export async function change_room(room: Room)
 
 	current_room.set(room);
 	layout.set("room");
+
+	return response;
 }
 
 export async function validate_password(room: Room)