From 4afc28ffcb8e6e206d76deac132602dde343ac9e Mon Sep 17 00:00:00 2001
From: Vladimir Kharlampidi <nolimits4web@gmail.com>
Date: Fri, 22 Feb 2019 22:00:46 +0300
Subject: [PATCH] Virtual: removeSlide, removeAllSlides + tweaks for
 preprendSlides

Fixes #2966
Ref ##2976
---
 demos/410-virtual-slides.html     | 10 ++++----
 src/components/virtual/virtual.js | 39 +++++++++++++++++++++++++++++--
 2 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/demos/410-virtual-slides.html b/demos/410-virtual-slides.html
index df944a1c0..c61a03c98 100644
--- a/demos/410-virtual-slides.html
+++ b/demos/410-virtual-slides.html
@@ -80,7 +80,7 @@
 
   <!-- Initialize Swiper -->
   <script>
-    var appendNumber = 1;
+    var appendNumber = 600;
     var prependNumber = 1;
     var swiper = new Swiper('.swiper-container', {
       slidesPerView: 3,
@@ -119,13 +119,13 @@
     document.querySelector('.prepend-2-slides').addEventListener('click', function (e) {
       e.preventDefault();
       swiper.virtual.prependSlide([
-        '<div class="swiper-slide">Slide ' + (--prependNumber) + '</div>',
-        '<div class="swiper-slide">Slide ' + (--prependNumber) + '</div>'
-        ]);
+        'Slide ' + (--prependNumber),
+        'Slide ' + (--prependNumber)
+      ]);
     });
     document.querySelector('.append-slide').addEventListener('click', function (e) {
       e.preventDefault();
-      swiper.virtual.appendSlide('<div class="swiper-slide">Slide ' + (++appendNumber) + '</div>');
+      swiper.virtual.appendSlide('Slide ' + (++appendNumber));
     });
   </script>
 </body>
diff --git a/src/components/virtual/virtual.js b/src/components/virtual/virtual.js
index c4696c770..2a95f9cff 100644
--- a/src/components/virtual/virtual.js
+++ b/src/components/virtual/virtual.js
@@ -133,7 +133,7 @@ const Virtual = {
     let newActiveIndex = activeIndex + 1;
     let numberOfNewSlides = 1;
 
-    if (typeof slides === 'object' && 'length' in slides) {
+    if (Array.isArray(slides)) {
       for (let i = 0; i < slides.length; i += 1) {
         if (slides[i]) swiper.virtual.slides.unshift(slides[i]);
       }
@@ -146,13 +146,46 @@ const Virtual = {
       const cache = swiper.virtual.cache;
       const newCache = {};
       Object.keys(cache).forEach((cachedIndex) => {
-        newCache[cachedIndex + numberOfNewSlides] = cache[cachedIndex];
+        newCache[parseInt(cachedIndex, 10) + numberOfNewSlides] = cache[cachedIndex];
       });
       swiper.virtual.cache = newCache;
     }
     swiper.virtual.update(true);
     swiper.slideTo(newActiveIndex, 0);
   },
+  removeSlide(slidesIndexes) {
+    const swiper = this;
+    if (typeof slidesIndexes === 'undefined' || slidesIndexes === null) return;
+    let activeIndex = swiper.activeIndex;
+    if (Array.isArray(slidesIndexes)) {
+      for (let i = slidesIndexes.length - 1; i >= 0; i -= 1) {
+        swiper.virtual.slides.splice(slidesIndexes[i], 1);
+        if (swiper.params.virtual.cache) {
+          delete swiper.virtual.cache[slidesIndexes[i]];
+        }
+        if (slidesIndexes[i] < activeIndex) activeIndex -= 1;
+        activeIndex = Math.max(activeIndex, 0);
+      }
+    } else {
+      swiper.virtual.slides.splice(slidesIndexes, 1);
+      if (swiper.params.virtual.cache) {
+        delete swiper.virtual.cache[slidesIndexes];
+      }
+      if (slidesIndexes < activeIndex) activeIndex -= 1;
+      activeIndex = Math.max(activeIndex, 0);
+    }
+    swiper.virtual.update(true);
+    swiper.slideTo(activeIndex, 0);
+  },
+  removeAllSlides() {
+    const swiper = this;
+    swiper.virtual.slides = [];
+    if (swiper.params.virtual.cache) {
+      swiper.virtual.cache = {};
+    }
+    swiper.virtual.update(true);
+    swiper.slideTo(0, 0);
+  },
 };
 
 export default {
@@ -175,6 +208,8 @@ export default {
         update: Virtual.update.bind(swiper),
         appendSlide: Virtual.appendSlide.bind(swiper),
         prependSlide: Virtual.prependSlide.bind(swiper),
+        removeSlide: Virtual.removeSlide.bind(swiper),
+        removeAllSlides: Virtual.removeAllSlides.bind(swiper),
         renderSlide: Virtual.renderSlide.bind(swiper),
         slides: swiper.params.virtual.slides,
         cache: {},