Vue router in-out page transition: transition in a new route while old route remains visible - vue.js

Question

To illustrate what I'm trying to achieve but also discuss and learn about each mechanism separately, I split the issue into two independent challenges:
1. Keep previous route visible until new route has transitioned in
Whether the transition is sliding, what I'm trying here, or just fading; mode in-out doesn't work as I would expect it, namely that the existing route stays visible until the next route has finished its transition (e.g. overlaid itself over the previous one), exactly as illustrated here in the last example of this section https://v2.vuejs.org/v2/guide/transitions.html#Transition-Modes, showing two buttons with in-out mode. Instead no transition is happening but it just flips the routes statically at half of the given transition time.
Is there any caveat with routes and an obvious reason why this wouldn't work the same way, e.g. that a single router-view can only hold one at the time and therefore in-out is not possible?
EDIT 1:
I figured out that in-out would actually only work with position:absolute on both elements, otherwise they will not overlay. Any idea how I could elegantly include such a behavior, potentially setting that absolute position during router-transition only?
Current hack that has the visual slide-up modal effect (mode: in-out) I'm looking for: adding style="position:absolute; z-index:2100" to the dialog route. Then I would need to change the underlying transition once it's shown in order to have the reverse hide effect (mode: out-in).
Also see EDIT 2 below.
2. Creating a modal-like page (route) which opens above another existing page when navigated to
I tried to hack that behavior by adding a second router-view in App.vue
<router-view />
<router-view name="dialog" />
The particular component is added to my routes like this
{
path: 'records/new',
components: {
dialog: () => import('layouts/NewRecord.vue')
},
children: [
{
name: 'new-record',
path: '',
component: () =>
import('src/pages/NewRecord.vue')
}
]
}
I'm not sure whether this approach even makes sense but I couldn't make it work properly. The aim would be to just overlay another router-view name="dialog whenever a "dialog"-path is pushed, so while it can be animated (slide-up) the other router-view stays visible below. In the end I guess I'm facing the same issue here: once the route changes, the initial router-view discards its component because the path does not match the current location anymore.
Either way, there are people out there with more experience and expertise so I hope I could illustrate what I'm trying to achieve and I'm just curious and thankful to read your inputs.
EDIT 2
I could make it work the way I wanted with simply one , wrapped in a custom page-transition component. It is quite a hack though AND I needed to add position: absolute to may page-layouts, to all of them actually (both the "leaving" and the "entering" component need position: absolute) when showing the dialog component. I'm sure there's a better way but I haven't found it so far.
Custom page-transition component:
<template>
<transition :name="name" :mode="mode">
<slot/>
</transition>
</template>
<script lang="ts">
import { Component, Watch } from 'vue-property-decorator'
import Vue from 'vue'
import { Route } from 'vue-router'
#Component({
components: {}
})
export default class PageTransition extends Vue {
NAME_FADE = 'fade'
NAME_SLIDE_UP = 'slide-up'
NAME_SLIDE_DOWN = 'slide-down'
MODE_OUT_IN = ''
MODE_IN_OUT = 'in-out'
name = this.NAME_FADE
mode = this.MODE_OUT_IN
#Watch('$route', { immediate: true, deep: true })
onRouteChanged(newVal: Route, oldVal: Route) {
if (newVal.meta.transition === 'dialog') {
this.name = this.NAME_SLIDE_UP
this.mode = this.MODE_IN_OUT
} else if (oldVal && oldVal.meta.transition === 'dialog') {
this.name = this.NAME_SLIDE_DOWN
// shift next page in immediately below dialog
this.mode = this.MODE_IN_OUT
} else {
// default
this.name = this.NAME_FADE
this.mode = this.MODE_OUT_IN
}
}
}
</script>
<style lang="scss" scoped>
.fade-enter, .fade-leave-to {
opacity: 0;
}
.fade-enter-active, .fade-leave-active {
transition: all 0.1s ease;
}
// start of enter element
.slide-up-enter {
transform: translateY(60%);
opacity: 0;
}
.slide-up-enter-active {
transition: all 0.3s ease-out;
z-index: 2100;
}
// start of leave element
.slide-up-leave, .slide-up-leave-active {
opacity: 0;
}
// start of leave element
.slide-down-leave {
z-index: 2100;
}
.slide-down-leave-to {
transform: translateY(60%);
opacity: 0;
z-index: 2100;
}
.slide-down-leave-active {
transition: all 0.3s ease-in;
}
// start of enter element
.slide-down-enter {
opacity: 0;
}
.slide-down-enter-active {
/* show immediately behind existing page (lower z-index) */
transition: all 0s;
}
</style>

Answer 1

I have a similar task. I was able to complete it using fixed containers and z-index shuffle. I met a number of issues related to scroll and vertical alignment, and, in my case, solving it using absolute position during router-transition only was not possible.
Here's the demo: https://kasheftin.github.io/vue-router-in-out-slide-scroll.
Also, I had to use localStorage to keep & restore page scroll position.
In my case page content has to be vertically aligned. That's why I could not use one global scrollable container (e.g. <body>). In-out mode transition works rather simple - it just appends the content, adds some classes and then removes the first child. That means in the middle there're two page containers side by side, and if one of them is tall (and forces the body to have scroll), then the other one appears in the middle of the body and has wrong vertical alignment.
So I just wrapped every page with fixed scrollable container. Assume we have a List and an Item pages, and the last should slide from the right and overlay the list. Then, the right-to-left animation is very simple:
.slide-right-enter-active {
transition: transform 1s ease;
.slide-right-enter {
transform: translateX(100%);
}
Left-to-right animation (overlay disappearing) has the wrong z-index. During the animation we have the following in the DOM:
<transition>
<Item />
<List />
</transition>
By default List will be shown over the Item, but it has to be below. So there're the rules:
.slideable-page {
position: fixed;
overflow: auto;
z-index: 2;
}
.slide-left-enter {
z-index: 1;
}
.slide-left-enter-active {
z-index: 1;
}
.slide-left-leave-active {
transition: transform 1s ease;
z-index: 3;
}
.slide-left-leave-to {
transform: translateX(100%);
}

Answer 2

For question 1: Have you added the CSS with it? The transition by itself only handles timing, you need to add the CSS for the transition to work (example: https://v2.vuejs.org/v2/guide/transitions.html#Transitioning-Single-Elements-Components).
.fade-enter-active, .fade-leave-active {
transition: opacity .5s;
}
.fade-enter, .fade-leave-to /* .fade-leave-active below version 2.1.8 */ {
opacity: 0;
}
For question 2:
I don't know if I understood correctly your situation, but if I did, here is what I would do, using nested routes.
layouts/NewRecord.vue
<template>
<router-view name="dialog"></dialog>
</template>
Routes
const routes = {
path: 'records/new',
component: () => import('layouts/NewRecord.vue'),
children: [
{
path: 'dialog',
components: {
dialog: () => import('src/pages/NewRecord.vue'),
},
},
],
}