From 2d51efd71612ec969b83c62d6aa0dac6df9391a3 Mon Sep 17 00:00:00 2001
From: sct <sctsnipe@gmail.com>
Date: Tue, 8 Dec 2020 02:11:14 +0000
Subject: [PATCH] feat(frontend): only load request/tmdb cards when in the
 browser view

---
 README.md                                        |  1 +
 package.json                                     |  1 +
 src/components/RequestCard/index.tsx             | 12 ++++++++++--
 src/components/RequestList/RequestItem/index.tsx |  8 ++++++--
 src/components/TitleCard/TmdbTitleCard.tsx       | 12 ++++++++++--
 yarn.lock                                        |  5 +++++
 6 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index f6cb6ae46..c414c996a 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,7 @@
 <img src="https://i.imgur.com/TMoEG7g.png" alt="Overseerr">
 </p>
 <p align="center">
+<img src="https://github.com/sct/overseerr/workflows/Overseerr%20Release/badge.svg?branch=master" alt="Overseerr Release" />
 <img src="https://github.com/sct/overseerr/workflows/Overseerr%20CI/badge.svg" alt="Overseerr CI">
 <a href="https://discord.gg/ySfaEUcQ">
 <img src="https://img.shields.io/discord/783137440809746482" alt="Discord">
diff --git a/package.json b/package.json
index 03d7ca99e..cfca949ac 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
     "pug": "^3.0.0",
     "react": "16.13.1",
     "react-dom": "16.13.1",
+    "react-intersection-observer": "^8.31.0",
     "react-intl": "^5.8.5",
     "react-spring": "^8.0.27",
     "react-toast-notifications": "^2.4.0",
diff --git a/src/components/RequestCard/index.tsx b/src/components/RequestCard/index.tsx
index 14ecac074..ee305e5c8 100644
--- a/src/components/RequestCard/index.tsx
+++ b/src/components/RequestCard/index.tsx
@@ -1,4 +1,5 @@
 import React, { useContext, useState } from 'react';
+import { useInView } from 'react-intersection-observer';
 import type { MediaRequest } from '../../../server/entity/MediaRequest';
 import type { TvDetails } from '../../../server/models/Tv';
 import type { MovieDetails } from '../../../server/models/Movie';
@@ -42,6 +43,9 @@ interface RequestCardProps {
 }
 
 const RequestCard: React.FC<RequestCardProps> = ({ request }) => {
+  const { ref, inView } = useInView({
+    triggerOnce: true,
+  });
   const intl = useIntl();
   const { hasPermission } = useUser();
   const { locale } = useContext(LanguageContext);
@@ -50,7 +54,7 @@ const RequestCard: React.FC<RequestCardProps> = ({ request }) => {
       ? `/api/v1/movie/${request.media.tmdbId}`
       : `/api/v1/tv/${request.media.tmdbId}`;
   const { data: title, error } = useSWR<MovieDetails | TvDetails>(
-    `${url}?language=${locale}`
+    inView ? `${url}?language=${locale}` : null
   );
   const { data: requestData, error: requestError, revalidate } = useSWR<
     MediaRequest
@@ -67,7 +71,11 @@ const RequestCard: React.FC<RequestCardProps> = ({ request }) => {
   };
 
   if (!title && !error) {
-    return <RequestCardPlaceholder />;
+    return (
+      <div ref={ref}>
+        <RequestCardPlaceholder />
+      </div>
+    );
   }
 
   if (!requestData && !requestError) {
diff --git a/src/components/RequestList/RequestItem/index.tsx b/src/components/RequestList/RequestItem/index.tsx
index e00b022f1..a36037d39 100644
--- a/src/components/RequestList/RequestItem/index.tsx
+++ b/src/components/RequestList/RequestItem/index.tsx
@@ -1,4 +1,5 @@
 import React, { useContext } from 'react';
+import { useInView } from 'react-intersection-observer';
 import type { MediaRequest } from '../../../../server/entity/MediaRequest';
 import {
   useIntl,
@@ -36,6 +37,9 @@ interface RequestItemProps {
 }
 
 const RequestItem: React.FC<RequestItemProps> = ({ request, onDelete }) => {
+  const { ref, inView } = useInView({
+    triggerOnce: true,
+  });
   const intl = useIntl();
   const { hasPermission } = useUser();
   const { locale } = useContext(LanguageContext);
@@ -44,7 +48,7 @@ const RequestItem: React.FC<RequestItemProps> = ({ request, onDelete }) => {
       ? `/api/v1/movie/${request.media.tmdbId}`
       : `/api/v1/tv/${request.media.tmdbId}`;
   const { data: title, error } = useSWR<MovieDetails | TvDetails>(
-    `${url}?language=${locale}`
+    inView ? `${url}?language=${locale}` : null
   );
   const { data: requestData, error: requestError, revalidate } = useSWR<
     MediaRequest
@@ -68,7 +72,7 @@ const RequestItem: React.FC<RequestItemProps> = ({ request, onDelete }) => {
 
   if (!title && !error) {
     return (
-      <tr className="w-full bg-gray-800 animate-pulse h-24">
+      <tr className="w-full bg-gray-800 animate-pulse h-24" ref={ref}>
         <td colSpan={6}></td>
       </tr>
     );
diff --git a/src/components/TitleCard/TmdbTitleCard.tsx b/src/components/TitleCard/TmdbTitleCard.tsx
index 8370a8125..40325a30b 100644
--- a/src/components/TitleCard/TmdbTitleCard.tsx
+++ b/src/components/TitleCard/TmdbTitleCard.tsx
@@ -1,4 +1,5 @@
 import React, { useContext } from 'react';
+import { useInView } from 'react-intersection-observer';
 import useSWR from 'swr';
 import type { MovieDetails } from '../../../server/models/Movie';
 import type { TvDetails } from '../../../server/models/Tv';
@@ -15,15 +16,22 @@ const isMovie = (movie: MovieDetails | TvDetails): movie is MovieDetails => {
 };
 
 const TmdbTitleCard: React.FC<TmdbTitleCardProps> = ({ tmdbId, type }) => {
+  const { ref, inView } = useInView({
+    triggerOnce: true,
+  });
   const { locale } = useContext(LanguageContext);
   const url =
     type === 'movie' ? `/api/v1/movie/${tmdbId}` : `/api/v1/tv/${tmdbId}`;
   const { data: title, error } = useSWR<MovieDetails | TvDetails>(
-    `${url}?language=${locale}`
+    inView ? `${url}?language=${locale}` : null
   );
 
   if (!title && !error) {
-    return <TitleCard.Placeholder />;
+    return (
+      <div ref={ref}>
+        <TitleCard.Placeholder />
+      </div>
+    );
   }
 
   if (!title) {
diff --git a/yarn.lock b/yarn.lock
index 9feb2dcf2..6c43d07c7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -11160,6 +11160,11 @@ react-fast-compare@^2.0.1:
   resolved "https://registry.yarnpkg.com/react-fast-compare/-/react-fast-compare-2.0.4.tgz#e84b4d455b0fec113e0402c329352715196f81f9"
   integrity sha512-suNP+J1VU1MWFKcyt7RtjiSWUjvidmQSlqu+eHslq+342xCbGTYmC0mEhPCOHxlW0CywylOC1u2DFAT+bv4dBw==
 
+react-intersection-observer@^8.31.0:
+  version "8.31.0"
+  resolved "https://registry.yarnpkg.com/react-intersection-observer/-/react-intersection-observer-8.31.0.tgz#0ed21aaf93c4c0475b22b0ccaba6169076d01605"
+  integrity sha512-XraIC/tkrD9JtrmVA7ypEN1QIpKc52mXBH1u/bz/aicRLo8QQEJQAMUTb8mz4B6dqpPwyzgjrr7Ljv/2ACDtqw==
+
 react-intl@^5.8.5:
   version "5.8.5"
   resolved "https://registry.yarnpkg.com/react-intl/-/react-intl-5.8.5.tgz#bc5dfab259049830621e129b8bffb1ac33ef4124"