How to prevent transition on tab change?

I'm struggling to prevent triggering a transition after switching a tab.

Example

const { createApp, reactive, ref } = Vue;
const app = createApp({
  setup() {      
    // switch tabs to see the side effects
    const currentTabIdx = ref(0);

    const listItems = ref([
      [
        { name: 'John', id: 1 },
        { name: 'Joao', id: 2 },
        { name: 'Jean', id: 3 },
        { name: 'Gerard', id: 4 },
      ],
      [
        { name: 'Max', id: 1 },
        { name: 'Moritz', id: 2 },
        { name: 'Foo', id: 3 },
        { name: 'Mo', id: 4 },
      ],
    ])
    
     function shuffleList() {
      listItems.value[currentTabIdx.value] = listItems.value[currentTabIdx.value].sort(() => Math.random() - 0.5);
    }
    
    return {
      currentTabIdx,
      listItems,
      shuffleList
    }
  }
});

app.component('list-component', {
  props: ['items'],

  template: `
    <ol>
      <transition-group>
        <li
          v-for="(effect, index) in items"
          :key="effect"
        >
          <div class="header">
            <h5>{{ effect.name }}</h5>
          </div>
        </li>
      </transition-group>
    </ol>
  `,
});

app.mount("#app");

li {
  transition: 0.5s;
}

.v-enter-active,
.v-leave-active {
  transition: opacity 0.5s;
}

.v-leave-active {
  position: absolute;
}

.v-enter,
.v-leave-to {
  opacity: 0;
}

<script src="https://unpkg.com/vue@next"></script>
<div id="app">

  <button @click="currentTabIdx=0">Tab 1</button> <!-- SWITCH TABS TO SEE SIDE EFFECTS -->
  <button @click="currentTabIdx=1">Tab 2</button> <!-- SWITCH TABS TO SEE SIDE EFFECTS -->
  | <button @click="shuffleList">Shuffle</button>

  <list-component :items="listItems[currentTabIdx]"></list-component>
  
  
</div>

Problem

The child component with the list and transition-group triggers side effects on tab navigation.

Tried

I have tried to disable the transition on the body with * { transition: none !important; } but than the list duplicates for a second.

Do you have an idea how to prevent the transition group on tab switch but enable it right afterwards?

Solution

How to prevent transition on tab change?

Maybe, there's a best way than preventing it.

If you can prefere this, you need to wrap the list-component with the keep-alive so that that the component is not destroyed and recreated each time the tab changes. As a result, the transition effect is maintained when reordering the list.

const { createApp, reactive, ref, nextTick } = Vue;
const app = createApp({
 setup() { 
 const currentTabIdx = ref(0);

 const listItems = ref([
 [
   { name: 'John', id: 1 },
   { name: 'Joao', id: 2 },
   { name: 'Jean', id: 3 },
   { name: 'Gerard', id: 4 },
 ],
 [
   { name: 'Max', id: 1 },
   { name: 'Moritz', id: 2 },
   { name: 'Foo', id: 3 },
   { name: 'Mo', id: 4 },
 ],
 ])

 function shuffleList() {
 listItems.value[currentTabIdx.value] = listItems.value[currentTabIdx.value].sort(() => Math.random() - 0.5);
 }

 nextTick(() => {
 shuffleList();
 });

 return {
 currentTabIdx,
 listItems,
 shuffleList
 }
 }
});

app.component('list-component', {
 props: ['items'],

 template: `
 <ol>
 <transition-group name="list" tag="ol" mode="out-in">
   <li
     v-for="(effect, index) in items"
     :key="effect.id"
   >
     <div class="header">
       <h5>{{ effect.name }}</h5>
     </div>
   </li>
 </transition-group>
 </ol>
 `,
});

app.mount("#app");

li {
 transition: 0.5s;
}

.list-enter-active,
.list-leave-active {
 transition: opacity 0.5s;
}

.list-leave-active {
 position: absolute;
}

.list-enter,
.list-leave-to {
 opacity: 0;
}

<script src="https://unpkg.com/vue@next"></script>

<div id="app">
 <button @click="currentTabIdx=0">Tab 1</button>
 <button @click="currentTabIdx=1">Tab 2</button>
 <button @click="shuffleList">Shuffle</button>

 <keep-alive>
 <component :is="'list-component'" :items="listItems[currentTabIdx]"></component>
 </keep-alive>
</div>

I use also the nextTick here to delay the call to shuffleList until the next DOM update cycle so that the transition-group applies the transition when the list is rendered.

Edit

the transition should stop between tabs, but within the list the transition should be applied.

const { createApp, reactive, ref } = Vue;
const app = createApp({
 setup() {     
   const currentTabIdx = ref(0);
   const listItems = ref([
     [
       { name: 'John', id: 1 },
       { name: 'Joao', id: 2 },
       { name: 'Jean', id: 3 },
       { name: 'Gerard', id: 4 },
     ],
     [
       { name: 'Max', id: 1 },
       { name: 'Moritz', id: 2 },
       { name: 'Foo', id: 3 },
       { name: 'Mo', id: 4 },
     ],
   ])
   
   function shuffleList() {
     listItems.value[currentTabIdx.value] = listItems.value[currentTabIdx.value].sort(() => Math.random() - 0.5);
   }
   
   return {
     currentTabIdx,
     listItems,
     shuffleList
   }
 }
});

app.component('list-component', {
 props: ['items'],
 template: `
   <ol>
     <transition-group>
       <li
         v-for="(effect, index) in items"
         :key="effect"
       >
         <div class="header">
           <h5>{{ effect.name }}</h5>
         </div>
       </li>
     </transition-group>
   </ol>
 `,
});

app.mount("#app");

li {
 transition: 0.5s;
}

.v-enter-active,
.v-leave-active {
 transition: opacity 0.5s;
}

.v-leave-active {
 position: absolute;
}

.v-enter,
.v-leave-to {
 opacity: 0;
}

<script src="https://unpkg.com/vue@next"></script>

<div id="app">
 <button @click="currentTabIdx=0">Tab 1</button> <!-- SWITCH TABS TO SEE SIDE EFFECTS -->
 <button @click="currentTabIdx=1">Tab 2</button> <!-- SWITCH TABS TO SEE SIDE EFFECTS -->
 | <button @click="shuffleList">Shuffle</button>

 <list-component v-show="currentTabIdx === 0" :items="listItems[0]"></list-component>
 <list-component v-show="currentTabIdx === 1" :items="listItems[1]"></list-component>
</div>

Here, the v-show is used to control the visibility of the list-component. When the currentTabIdx changes, only the display of the list component is toggled, and no transition is triggered.