Add background notif text to subscribe dialog

only when web push is enabled

web/public/static/langs/en.json

@@ -171,6 +171,7 @@
   "subscribe_dialog_subscribe_description": "Topics may not be password-protected, so choose a name that's not easy to guess. Once subscribed, you can PUT/POST notifications.",
   "subscribe_dialog_subscribe_topic_placeholder": "Topic name, e.g. phil_alerts",
   "subscribe_dialog_subscribe_use_another_label": "Use another server",
+  "subscribe_dialog_subscribe_use_another_background_info": "Note: Background notifications are not supported on other servers",
   "subscribe_dialog_subscribe_base_url_label": "Service URL",
   "subscribe_dialog_subscribe_button_generate_topic_name": "Generate name",
   "subscribe_dialog_subscribe_button_cancel": "Cancel",

web/src/components/SubscribeDialog.jsx

@@ -14,6 +14,7 @@ import {
   Switch,
 } from "@mui/material";
 import { useTranslation } from "react-i18next";
+import { useLiveQuery } from "dexie-react-hooks";
 import theme from "./theme";
 import api from "../app/Api";
 import { randomAlphanumericString, topicUrl, validTopic, validUrl } from "../app/utils";
@@ -28,6 +29,7 @@ import ReserveTopicSelect from "./ReserveTopicSelect";
 import { AccountContext } from "./App";
 import { TopicReservedError, UnauthorizedError } from "../app/errors";
 import { ReserveLimitChip } from "./SubscriptionPopup";
+import prefs from "../app/Prefs";
 
 const publicBaseUrl = "https://ntfy.sh";
 
@@ -96,6 +98,8 @@ const SubscribePage = (props) => {
   const reserveTopicEnabled =
     session.exists() && (account?.role === Role.ADMIN || (account?.role === Role.USER && (account?.stats.reservations_remaining || 0) > 0));
 
+  const webPushEnabled = useLiveQuery(() => prefs.webPushEnabled());
+
   const handleSubscribe = async () => {
     const user = await userManager.get(baseUrl); // May be undefined
     const username = user ? user.username : t("subscribe_dialog_error_user_anonymous");
@@ -233,12 +237,19 @@ const SubscribePage = (props) => {
                 inputValue={props.baseUrl}
                 onInputChange={updateBaseUrl}
                 renderInput={(params) => (
+                  <>
                     <TextField
                       {...params}
                       placeholder={config.base_url}
                       variant="standard"
                       aria-label={t("subscribe_dialog_subscribe_base_url_label")}
                     />
+                    {webPushEnabled && (
+                      <div style={{ width: "100%", color: "#aaa", fontSize: "0.75rem", marginTop: "0.5rem" }}>
+                        {t("subscribe_dialog_subscribe_use_another_background_info")}
+                      </div>
+                    )}
+                  </>
                 )}
               />
             )}