From d0989ac58b70eaa09a1030b8805a7b9b6672d2a8 Mon Sep 17 00:00:00 2001
From: Fedor Katurov <gotham48@gmail.com>
Date: Mon, 21 Jun 2021 14:00:21 +0700
Subject: [PATCH] #38 fixed preloader

---
 .../node/NodeImageSwiperBlock/index.tsx       | 22 ++++++++++++++-----
 .../NodeImageSwiperBlock/styles.module.scss   |  7 ++++++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/components/node/NodeImageSwiperBlock/index.tsx b/src/components/node/NodeImageSwiperBlock/index.tsx
index 29278f6b..c44f3cb1 100644
--- a/src/components/node/NodeImageSwiperBlock/index.tsx
+++ b/src/components/node/NodeImageSwiperBlock/index.tsx
@@ -5,18 +5,20 @@ import { Swiper, SwiperSlide } from 'swiper/react';
 import 'swiper/swiper.scss';
 import 'swiper/components/pagination/pagination.scss';
 import 'swiper/components/navigation/navigation.scss';
+import 'swiper/components/lazy/lazy.min.css';
 import styles from './styles.module.scss';
 
-import SwiperCore, { Keyboard, Navigation, Pagination, SwiperOptions } from 'swiper';
+import SwiperCore, { Keyboard, Navigation, Pagination, SwiperOptions, Lazy } from 'swiper';
 
 import { useNodeImages } from '~/utils/hooks/node/useNodeImages';
-import { getURL } from '~/utils/dom';
-import { PRESETS } from '~/constants/urls';
 import SwiperClass from 'swiper/types/swiper-class';
 import { modalShowPhotoswipe } from '~/redux/modal/actions';
 import { useDispatch } from 'react-redux';
+import classNames from 'classnames';
+import { getURL } from '~/utils/dom';
+import { PRESETS } from '~/constants/urls';
 
-SwiperCore.use([Navigation, Pagination, Keyboard]);
+SwiperCore.use([Lazy, Navigation, Pagination, Keyboard]);
 
 interface IProps extends INodeComponentProps {}
 
@@ -78,6 +80,7 @@ const NodeImageSwiperBlock: FC<IProps> = ({ node }) => {
         watchOverflow
         updateOnImagesReady
         onInit={resetSwiper}
+        lazy
         keyboard={{
           enabled: true,
           onlyInViewport: false,
@@ -90,12 +93,19 @@ const NodeImageSwiperBlock: FC<IProps> = ({ node }) => {
         {images.map(file => (
           <SwiperSlide className={styles.slide} key={file.id}>
             <img
-              className={styles.image}
-              src={getURL(file, PRESETS['1600'])}
+              className={classNames('swiper-lazy', styles.image)}
+              data-src={getURL(file, PRESETS['1600'])}
               alt={node.title}
               onLoad={updateSwiper}
               onClick={onOpenPhotoSwipe}
             />
+
+            <div
+              className={classNames(
+                'swiper-lazy-preloader swiper-lazy-preloader-white',
+                styles.loader
+              )}
+            />
           </SwiperSlide>
         ))}
       </Swiper>
diff --git a/src/components/node/NodeImageSwiperBlock/styles.module.scss b/src/components/node/NodeImageSwiperBlock/styles.module.scss
index 6f985e9d..c1c82fb9 100644
--- a/src/components/node/NodeImageSwiperBlock/styles.module.scss
+++ b/src/components/node/NodeImageSwiperBlock/styles.module.scss
@@ -98,6 +98,11 @@
   border-radius: $radius;
   transition: box-shadow 1s;
   box-shadow: transparentize(black, 0.7) 0 3px 5px;
+  opacity: 0;
+
+  &[src] {
+    opacity: 1;
+  }
 
   :global(.swiper-slide-active) & {
     box-shadow: transparentize(black, 0.9) 0 10px 5px 4px,
@@ -113,3 +118,5 @@
   }
 }
 
+.loader {
+}