I'm trying to render a header only if there's a text or a populated slot inside of it.
I tried:
<div
class="flex py-sm px-md w-full align-middle rounded-t-xl"
v-if="props.title || $slots.header"
:class="[`bg-${props.headerColor}`]"
>
<p class="text-bo-xl font-bold" :class="`text-${props.titleTextColor}`">
{{ props.title }}
</p>
<slot name="header"></slot>
</div>
But the div renders anyway, even if the slot is empty. I think it considers the slot present even if it's not populated.
Any ideas?
sorry for the late response. If I utilize computed() it seems to work:
<template>
<section>
<h4>lorem</h4>
<div v-if="hasHeaderSlot">
<h2>ipsum</h2>
<slot name="header"></slot>
</div>
</section>
</template>
<script>
import { computed } from 'vue';
export default {
setup(_, { slots }) {
const hasHeaderSlot = computed(() => slots.header && slots.header());
return {
hasHeaderSlot,
};
},
};
</script>
I hope this helps. With best regards
I am new to vueJS.
What I want to do is passing parameters to a component, depending on the selection of the routes. Here is my App.vue:
<template>
<div id="main">
<header>
<h1 style="color:red">{{msg}}</h1>
</header>
<div>
<aside class="sidebar">
<router-link v-for="el in this.$router.options.routes" :to="el">
{{el.name}}
</router-link>
</aside>
<SubMenu></SubMenu>
<div class="content">
<router-view></router-view>
</div>
</div>
</div>
</template>
<script>
import SubMenu from './components/SubMenu.vue'
export default {
components: {
'SubMenu': SubMenu
},
data() {
return {
msg: 'Welcome to Your Vue.js App' }
}
}
</script>
<style>
#import 'style.css';
#import 'grid.css';
</style>
and the SubMenu component I would like to make dynamic:
<template>
<div>
something dynamic
</div>
</template>
How can I pass some parameters to use in the component?
thank you
Your App.vue can be like this:
<template>
<div id="main">
<header>
<h1 style="color:red">{{msg}}</h1>
</header>
<div>
<aside class="sidebar">
<router-link v-for="el in this.$router.options.routes" :to="el">
{{el.name}}
</router-link>
</aside>
<SubMenu :menuTitle="subMenuTitle"></SubMenu>
<div class="content">
<router-view></router-view>
</div>
</div>
</div>
</template>
<script>
import SubMenu from './components/SubMenu.vue';
export default {
components: {
SubMenu
},
data() {
return {
subMenuTitle: "This is the sub menu",
msg: 'Welcome to Your Vue.js App'
}
}
}
</script>
<style>
#import 'style.css';
#import 'grid.css';
</style>
The SubMenu.vue component could be like this:
<template>
<div>
<h2>{{ menuTitle }}</h2>
something dynamic
</div>
</template>
<script>
export default {
name: "SubMenu",
props: {
menuTitle: String,
}
}
</script>
In the SubMenu component that was used in App.vue, notice the colon that appears before the menuTitle attribute. When you do that before an attribute, the value of that attribute would be evaluated by Vue and passed to the component. You can pass literal Javascript expressions or items in your App.vue component.
In the SubMenu component, you can use the props in whatever way you can. If the prop's value is an array, you can use the v-for directive with it to create a list of items in the SubMenu.
Welcome to SO,
In Vue.js passing parameters to components is called "Props"
You can pass props to your SubMenu like below
<SubMenu :id="12345" someText="Some Text About Something" :dataArray="[1,2,3,4,5]" />
then inside your SubMenu component you can define Prop Types as below
props: ['dataArray']
or
props: {
dataArray: {
type: Array,
default: []
}
}
After that you can use the data you passed to your liking
You can also read up on this Vue Documentation regarding the Props, which has much more detailed explanations about various Props related stuff and sample code
Ok many thanks to both.
But what if I would like to pass something that depends on the voices in router-link? I mean, router-link prints a menu with 4 voices...what if I would like a behavior like this:
click on voice1 in router-link ---> pass this object ['input1', 'input2'] to SubMenu
click on voice2 in router-link ---> pass this other object ['input3', 'input4', 'input5'] to SubMenu
and so on.
thanks again :)
I'm trying to add some animations to my vuejs(v2)+nuxt site using GSAP. To do that I need to trigger some animations on scroll. Vue provides some handy javascript hooks for it but they seem to not be working in my case.
<template>
<div class="container-xxl">
<div class="row">
<div class="col-12">
<div class="text-center">
<transition #before-enter="beforeEnter" #enter="enter" #leave="leave">
<h1>Test Component</h1>
</transition>
</div>
</div>
</div>
</div>
</template>
<script>
export default {
name: 'TestComponent',
methods: {
beforeEnter (el) {
console.log('before enter')
},
enter (el, done) {
console.log('enter')
},
leave (el, done) {
console.log('leave')
}
}
}
</script>
When using JavaScript-only transitions, the done callbacks are required for the enter and leave hooks. Otherwise, the hooks will be called synchronously and the transition will finish immediately.
I have a component like this:
<test></test>
I declare this as follows:
Vue.component('test', {
data: {
showModal: true
},
methods: {
displayComponentModalDialog: function() {
this.showModal = true;
}
},
template: `<button #click='displayComponentModalDialog'>test</button>`
});
The <test></test> component is then placed somewhere inside the <div id="#app"> wrapper.
var app = new Vue({
router,
el: '#app',
// etc.
})
Now, I want to display another component inside the test component. So in this case I want a dialog to appear after I click the button in test component. I am not able to achieve this.
What I did is adding a new component:
Vue.component('dialog', {
template: '#dialog-template'
});
And then the following code, although I do not know for sure where to put it.
<!-- template for the modal component -->
<script type="text/x-template" id="dialog-template">
<transition name="dialog">
<div class="modal-mask">
<div class="modal-wrapper">
<div class="modal-container">
<div class="modal-header">
<slot name="header">
default header
</slot>
</div>
<div class="modal-body">
<slot name="body">
default body
</slot>
</div>
<div class="modal-footer">
<slot name="footer">
<button class="btn btn-primary" #click="$emit('close')">
OK
</button>
</slot>
</div>
</div>
</div>
</div>
</transition>
</script>
<!-- use the modal component, pass in the prop -->
<dialog v-if="showModal" #close="showModal = false">
<h3 slot="header">header</h3>
<p slot="body">
test
</p>
</dialog>
I tried putting this code inside the <test></test> but doesn't work. If I put it inside the template attribute in the component structure, it complains about only one root element.
So it is clear I miss some basic conception how this actually works in VueJS. Someone can help me clarify? Thanks.
As far as I can see your component indeed doesn't have a root tag. Templates have to have a root tag.
This is NOT a valid Vue template:
<div>
<h1>Stuff</h1>
</div>
<h2>Other stuff</h2>
This IS a valid Vue template:
<div>
<div>
<h1>Stuff</h1>
</div>
<h2>Other stuff</h2>
</div>
Note that in the second version we have a single root element for the template, a <div>, whereas in the first one we do not.
You have both a <script></script> and a <dialog></dialog> in your component template.
if you want to add another component in your test component . you can use slot on it.
You can refer to this documentation: https://v2.vuejs.org/v2/guide/components-slots.html
Example:
//component 1
<template>
<div id="modal">
// do something for your modal here.
<slot></slot> // reserve area for your another html or component.
</div>
</template>
// component 2
<template>
<your-modal-component>
<another-component>
</your-modal-component>
</template>
Is there a way to only display a slot if it has any content?
For example, I'm building a simple Card.vue component, and I only want the footer displayed if the footer slot has content:
Template
<template>
<div class="panel" :class="panelType">
<div class="panel-heading">
<h3 class="panel-title">
<slot name="title">
Default Title
</slot>
</h3>
</div>
<div class="panel-body">
<slot name="body"></slot>
<p class="category">
<slot name="category"></slot>
</p>
</div>
<div class="panel-footer" v-if="hasFooterSlot">
<slot name="footer"></slot>
</div>
</div>
</template>
Script
<script>
export default {
props: {
active: true,
type: {
type: String,
default: 'default',
},
},
computed: {
panelType() {
return `panel-${this.type}`;
},
hasFooterSlot() {
return this.$slots['footer']
}
}
}
</script>
In in View:
<card type="success"></card>
Since the above component doesn't contain a footer, it should not be rendered, but it is.
I've tried using this.$slots['footer'], but this returns undefined.
Does anyone have any tips?
It should be available at
this.$slots.footer
So, this should work.
hasFooterSlot() {
return !!this.$slots.footer;
}
Example.
You should check vm.$slots and also vm.$scopedSlots for it.
hasSlot (name = 'default') {
return !!this.$slots[ name ] || !!this.$scopedSlots[ name ];
}
CSS simplifies this a lot. Just use the following code and voila!
.panel-footer:empty {
display: none;
}
This is the solution for Vue 3 composition API:
<template>
<div class="md:grid md:grid-cols-5 md:gap-6">
<!-- Here, you hide the wrapper if there is no used slot or empty -->
<div class="md:col-span-2" v-if="hasTitle">
<slot name="title"></slot>
</div>
<div class="mt-5 md:mt-0"
:class="{'md:col-span-3': hasTitle, 'md:col-span-5': !hasTitle}">
<div class="bg-white rounded-md shadow">
<div class="py-7">
<slot></slot>
</div>
</div>
</div>
</div>
</template>
<script>
import {ref} from "vue";
export default {
setup(props, {slots}) {
const hasTitle = ref(false)
// Check if the slot exists by name and has content.
// It returns an empty array if it's empty.
if (slots.title && slots.title().length) {
hasTitle.value = true
}
return {
hasTitle
}
}
}
</script>
Now, in Vue3 composition API , you can use useSlots.
<script setup>
import { useSlots } from 'vue'
const slots = useSlots()
</script>
<template>
<div v-if="slots.content" class="classname">
<slot name="content"></slot>
</div>
</template>
In short do this in inline:
<template lang="pug">
div
h2(v-if="$slots.title")
slot(name="title")
h3(v-if="$slots['sub-title']")
slot(name="sub-title")
</template>
I have ran into a similiar issue but across a wide code base and when creating atomic design structured components it can be tiring writing hasSlot() methods all the time and when it comes to TDD - its one more method to test... Saying that, you can always put the raw logic in a v-if but i have found that the template end up cluttered and harder to read on occasions especially for a new dev checking out the code structure.
I was tasked to find out a way of removing parent divs of slots when the slot isnt provided.
Issue:
<template>
<div>
<div class="hello">
<slot name="foo" />
</div>
<div class="world">
<slot name="bar" />
</div>
</div>
</template>
//instantiation
<my-component>
<span slot="foo">show me</span>
</my-component>
//renders
<div>
<div class="hello">
<span slot="foo">show me</span>
</div>
<div class="world"></div>
</div>
as you can see, the issue is that i have an almost 'trailing' div, that could provide styling issues when the component author decides there is no need for a bar slot.
ofcourse we could go <div v-if="$slots.bar">...</div> or <div v-if="hasBar()">...</div> etc but like i said - that can get tiresome and eventually end up harder to read.
Solution
My solution was to make a generic slot component that just rendered out a slot with a surrounding div...see below.
//slot component
<template>
<div v-if="!!$slots.default">
<slot />
</div>
</template>
//usage within <my-component/>
<template>
<div>
<slot-component class="hello">
<slot name="foo"/>
</slot-component>
<slot-component class="world">
<slot name="bar"/>
</slot-component>
</div>
</template>
//instantiation
<my-component>
<span slot="foo">show me</span>
</my-component>
//renders
<div>
<div class="hello">
<span>show me</span>
</div>
</div>
I came into use-case issues when trying this idea and sometimes it was my markup structure that needed to change for the benefit of this approach.
This approach reduces the need for small slot checks within each component template. i suppose you could see the component as a <conditional-div /> component...
It is also worth noting that applying attributes to the slot-component instantiation (<slot-component class="myClass" data-random="randomshjhsa" />) is fine as the attributes trickle into the containing div of the slot-component template.
Hope this helps.
UPDATE
I wrote a plugin for this so the need for importing the custom-slot component in each consumer component is not needed anymore and you will only have to write Vue.use(SlotPlugin) in your main.js instantiation. (see below)
const SLOT_COMPONENT = {
name: 'custom-slot',
template: `
<div v-if="$slots.default">
<slot />
</div>
`
}
const SLOT_PLUGIN = {
install (Vue) {
Vue.component(SLOT_COMPONENT.name, SLOT_COMPONENT)
}
}
export default SLOT_PLUGIN
//main.js
import SlotPlugin from 'path/to/plugin'
Vue.use(SlotPlugin)
//...rest of code
Initially I thought https://stackoverflow.com/a/50096300/752916 was working, but I had to expand on it a bit since $scopeSlots returns a function which is always truthy regardless of its return value. This is my solution, though I've come to the conclusion that the real answer to this question is "doing this is an antipattern and you should avoid it if possible". E.g. just make a separate footer component that could be slotted in.
Hacky solution
hasFooterSlot() {
const ss = this.$scopedSlots;
const footerNodes = ss && ss.footer && ss.footer();
return footerNodes && footerNodes.length;
}
Best Practice (helper component for footer)
const panelComponent = {
template: `
<div class="nice-panel">
<div class="nice-panel-content">
<!-- Slot for main content -->
<slot />
</div>
<!-- Slot for optional footer -->
<slot name="footer"></slot>
</div>
`
}
const footerComponent = {
template: `
<div class="nice-panel-footer">
<slot />
</div>
`
}
var app = new Vue({
el: '#app',
components: {
panelComponent,
footerComponent
},
data() {
return {
name: 'Vue'
}
}
})
.nice-panel {
max-width: 200px;
border: 1px solid lightgray;
}
.nice-panel-content {
padding: 30px;
}
.nice-panel-footer {
background-color: lightgray;
padding: 5px 30px;
text-align: center;
}
<script src="https://unpkg.com/vue#2.6.11/dist/vue.min.js"></script>
<div id="app">
<h1>Panel with footer</h1>
<panel-component>
lorem ipsum
<template #footer>
<footer-component> Some Footer Content</footer-component>
</template>
</panel-component>
<h1>Panel without footer</h1>
<panel-component>
lorem ipsum
</panel-component>
</div>
Hope I understand this right. Why not using a <template> tag, which is not rendered, if the slot is empty.
<slot name="foo"></slot>
Use it like this:
<template slot="foo">
...
</template>
For Vue 3:
Create an utility function
//utils.js
function isSlotHasContent(slotName, slots) {
return Boolean(!!slots[slotName] && slots[slotName]()[0].children.length > 0);
}
In your component:
<script setup>
import { isSlotHasContent } from 'path/to/utils.js';
const slots = useSlots();
// "computed" props has a better performance
const isFooSlotHasContent = computed(() => isSlotHasContent('foo', slots));
</script>
<template>
<div>
<div v-if="isFooSlotHasContent">
<slot name="foo" />
</div>
<div v-if="!isFooSlotHasContent">
Some placeholder
</div>
</div>
</template>
TESTED
So this work for me in vue 3:
I use onMounted to first get the value, and then onUpdate so the value can update.
<template>
<div v-if="content" class="w-1/2">
<slot name="content"></slot>
</div>
</template>
<script>
import { ref, onMounted, defineComponent, onUpdated } from "vue";
export default defineComponent({
setup(props, { slots }) {
const content = ref()
onMounted(() => {
if (slots.content && slots.content().length) {
content.value = true
}
})
onUpdated(() => {
content.value = slots.content().length
console.log('CHECK VALUE', content.value)
})
})
</script>
#Bert answer does not seem to work for dynamic templates like <template v-slot:foo="{data}"> ... </template>.
i ended up using:
return (
Boolean(this.$slots.foo) ||
Boolean(typeof this.$scopedSlots.foo == 'function')
);
I like the Solution of #AlexMA however in my case I needed to pass props to the function in order to get the nodes to show up.
Here is an example of how I am passing the "row" to the scoped slot, in my case the row contains a type param that I want to test against in the calling component.
<other-component>
<template v-slot:expand="{ row }" v-if="!survey.editable">
<div v-if="row.type != 1" class="flex">
{{ row }}
</div>
</template>
</other-component>
In "other-component" I have the template defined as
<template>
<div>
<div v-for="(row, index) in rows">
{{ hasSlotContent(row) }}
<slot name="expand" :row="row"> </slot>
</div>
</div>
</template>
Because the v-slot requires "row" to be passed to it I created a a method
methods:{
hasSlotContent(row){
const ss = this.$scopedSlots
const nodes = ss && ss.expand && ss.expand({ row: row })
return !!(nodes && nodes.length)
}
}
I call this on each iteration so that it can evaluate itself and give back the appropriate response.
you can use the "hasSlotContent(row)" method where-ever you need it, in my example I'm just outputting the truthy value to the DOM.
I hope this helps someone come to a quicker solution.
Reposting a Vue 3 solution from Github, which also works with Options API, since there was a fairly upvoted method from an Issue there:
The comment itself: https://github.com/vuejs/core/issues/4733#issuecomment-1024816095
The function (remove types if you're not writing TypeScript):
import {
Comment,
Text,
Slot,
VNode,
} from 'vue';
export function hasSlotContent(slot: Slot|undefined, slotProps = {}): boolean {
if (!slot) return false;
return slot(slotProps).some((vnode: VNode) => {
if (vnode.type === Comment) return false;
if (Array.isArray(vnode.children) && !vnode.children.length) return false;
return (
vnode.type !== Text
|| (typeof vnode.children === 'string' && vnode.children.trim() !== '')
);
});
}
This works just as fine, if you delete the slotProps argument (unless you need it).