Vue - how to pass down slots inside wrapper component? - vue.js

So I've created a simple wrapper component with template like:
<wrapper>
<b-table v-bind="$attrs" v-on="$listeners"></b-table>
</wrapper>
using $attrs and $listeners to pass down props and events.
Works fine, but how can the wrapper proxy the <b-table> named slots to the child?

Vue 3
Same as the Vue 2.6 example below except:
$listeners has been merged into $attrs so v-on="$listeners" is no longer necessary. See the migration guide.
$scopedSlots is now just $slots. See migration guide.
Vue 2.6 (v-slot syntax)
All ordinary slots will be added to scoped slots, so you only need to do this:
<wrapper>
<b-table v-bind="$attrs" v-on="$listeners">
<template v-for="(_, slot) of $scopedSlots" v-slot:[slot]="scope"><slot :name="slot" v-bind="scope"/></template>
</b-table>
</wrapper>
Vue 2.5
See Paul's answer.
Original answer
You need to specify the slots like this:
<wrapper>
<b-table v-bind="$attrs" v-on="$listeners">
<!-- Pass on the default slot -->
<slot/>
<!-- Pass on any named slots -->
<slot name="foo" slot="foo"/>
<slot name="bar" slot="bar"/>
<!-- Pass on any scoped slots -->
<template slot="baz" slot-scope="scope"><slot name="baz" v-bind="scope"/></template>
</b-table>
</wrapper>
Render function
render(h) {
const children = Object.keys(this.$slots).map(slot => h('template', { slot }, this.$slots[slot]))
return h('wrapper', [
h('b-table', {
attrs: this.$attrs,
on: this.$listeners,
scopedSlots: this.$scopedSlots,
}, children)
])
}
You probably also want to set inheritAttrs to false on the component.

I have been automating the passing of any (and all) slots using v-for, as shown below. The nice thing with this method is that you don't need to know which slots have to be passed on, including the default slot. Any slots passed to the wrapper will be passed on.
<wrapper>
<b-table v-bind="$attrs" v-on="$listeners">
<!-- Pass on all named slots -->
<slot v-for="slot in Object.keys($slots)" :name="slot" :slot="slot"/>
<!-- Pass on all scoped slots -->
<template v-for="slot in Object.keys($scopedSlots)" :slot="slot" slot-scope="scope"><slot :name="slot" v-bind="scope"/></template>
</b-table>
</wrapper>

Here is updated syntax for vue >2.6 with scoped slots and regular slots, thanks Nikita-Polyakov, link to discussion
<!-- pass through scoped slots -->
<template v-for="(_, scopedSlotName) in $scopedSlots" v-slot:[scopedSlotName]="slotData">
<slot :name="scopedSlotName" v-bind="slotData" />
</template>
<!-- pass through normal slots -->
<template v-for="(_, slotName) in $slots" v-slot:[slotName]>
<slot :name="slotName" />
</template>
<!-- after iterating over slots and scopedSlots, you can customize them like this -->
<template v-slot:overrideExample>
<slot name="overrideExample" />
<span>This text content goes to overrideExample slot</span>
</template>

This solution for Vue 3.2 version and above
<template v-for="(_, slot) in $slots" v-slot:[slot]="scope">
<slot :name="slot" v-bind="scope || {}" />
</template>

Related

Slot on Vuetify.js custom component

I have a component which renders a standard .
I would like to use slots from my component, I would like to write something like:
<MyComponent>
<header>
Titolo
</header>
<body>
my component body
</body>
</MyComponent>
then final component should be:
<v-dialog>
<h1>
// header slot content
</h1>
// body slot content
</v-dialog>
how can I do this? This only works with <slot> but not with named slot.
To use multiple slots you can use the following syntax:
<MyComponent>
<template v-slot:header>
Titolo
</template>
<template v-slot:body>
<p>my component body</p>
</template>
</MyComponent>
So you can pass some HTML in the template blocks and it will render in the component.
MyComponent.vue has the next content:
<template>
<v-dialog>
<h1>
<slot name="header"></slot>
</h1>
<slot name="body"></slot>
</v-dialog>
</template>
You can define names for your slots in your custom component by using the name attribute available for the <slot> element, e.g. <slot name="header">. If you don't define a name for the slot, its name will just be default. See the Vue.js slots documentation here: https://v2.vuejs.org/v2/guide/components-slots.html
Also, I made a simple usage example that you can check out here: https://codesandbox.io/s/unruffled-mopsa-f47hm?file=/src/App.vue
So in your case, your custom component could look something like this:
<v-dialog>
<slot name="header" />
<slot name="body" />
</v-dialog>
And to use it in the parent component, you could have:
<MyComponent>
<template v-slot:header>
Titolo
</template>
<template v-slot:body>
<p>my component body</p>
</template>
</MyComponent>

Hoist slot content up one level

I hope someone can help me out with this problem! I'm using a Table component from PrimeVue, and I'm looking to create a wrapper component with a slot for content. The problem is, the component will only recognize content directly within its default slot. Nothing else is recognized.
Code:
<template>
<DataTable :value="data">
<!-- These components are recognized -->
<Column v-for="col in cols" :key="col.field" :field="col.field" :header="col.header" />
<slot name="override" :cols="cols">
<!-- These components are not -->
<Column v-for="col in cols" :key="col.field" :field="col.field" :header="col.header" />
</slot>
</DataTable>
</template>
<script>
export default {
data() {
return {
data: // Array of data here,
cols: // Array of cols here
}
}
}
</script>
I checked their implementation, DataTable only looks in $slots.default().children for content. Since the content in <slot name="override"> will show up as something along the lines of $slots.default().children.children, they are not recognized. Is there a way for me to hoist or inject any content (including the default content if possible) from the slot into its parent so the content appears in $slots.default().children?
This template:
<template>
<slot name="heading">
<h1>Default heading</h1>
<h2>Default subheading</h2>
</slot>
</template>
...is effectively the same as conditionally rendering the <slot> with v-if="$slots.heading" (which is only truthy when the heading slot is actually passed in) and moving its inner contents to a v-else block:
<template>
<slot v-if="$slots.heading" name="heading">
</slot>
<template v-else>
<h1>Default Heading</h1>
<h2>Default subheading</h2>
</template>
</template>
So, you can use v-if="$slots.override" to conditionally render the <slot>, and move its contents (i.e., the <Column>s) into a v-else block:
<DataTable :value="data">
<slot v-if="$slots.override" name="override" :cols="cols" />
<Column v-else v-for="col in cols" :key="col.field" :field="col.field" :header="col.header" />
</DataTable>
demo

Is it possible to pass props from child component to template?

Is this possible?
Send props from child to parent...
Child.vue
<template showLogo="false">
...
</template>
Parent.vue
<template>
<div v-if="showLogo">
<logo>
</div>
....
</template>
This is pretty much scoped slots: https://v2.vuejs.org/v2/guide/components-slots.html#Scoped-Slots
As in your example:
parent.vue
<child>
<template v-slot="{ showLogo }">
<logo v-if="showLogo">
</logo>
</template>
</child>
This video is quite helpful on the subject: https://adamwathan.me/the-trick-to-understanding-scoped-slots-in-vuejs/
But I'd recommend reading about slots at first, beware because it's a more advanced pattern.

How to access or pass props to child slot in vue

If you have this component hierarchy, is it possible to pass or access isPanelClickable from ComponentPanel in ComponentSomething?
<ComponentA>
<ComponentPanel :isPanelClickable="false">
<ComponentSomething />
</ComponentPanel>
</ComponentA>
ComponentPanel:
<template>
<div class="panel">
<slot /> <!-- Can I "use" 'isPanelClickable' here somehow..? -->
</div>
</template>
This is possible through scoped slots. ComponentPanel could pass a prop to the default slot by binding the prop (e.g., named myProp) on the corresponding <slot> element:
<template>
<slot :myProp="isPanelClickable ? 'I am clickable' : 'I do nothing'" />
</template>
That prop is then passed through the v-slot in the default slot:
<ComponentPanel>
<template v-slot="{ myProp }">
<ComponentSomething :foo="myProp" />
</template>
</ComponentPanel>
demo

Vuejs nested slots: how to pass slot to grandchild

I use different vuetify components, for example v-menu. It has a template like this:
<v-menu>
<a slot="activator">menu</a>
<v-list>
<v-list-tile>Menu Entry 1</v-list-tile>
<v-list-tile>Menu Entry 2</v-list-tile>
</v-list>
</v-menu>
Suppose I want to add another wrapper around it. That is my special menu component that has some predefined menu options. And I want it to has an activator slot as well. And the last should be somehow assigned to the original v-menu activator slot. Is it possible?
Example:
// index.vue:
<template>
<my-special-menu>
<button>My special menu trigger</button>
</my-special-menu>
</template>
// MySpecialMenu.vue
<template>
<v-menu>
<slot slot="activator"/> <-- I don't know how to write this line
<v-list>...</v-list>
</v-menu>
</template>
<slot slot="activator"> is an incorrect equation. The goal is to pull the content from the parent (that is <button>..</button> in the example), and use it as slot="activator" in v-menu.
I can write it like this:
<v-menu>
<a slot="activator"><slot/></a>
...
</v-menu>
But this case the result template will be:
<div class="v-menu__activator">
<a>
<button>My special menu trigger</button>
</a>
</div>
That's not exactly what I want. Is it possible to get rid off <a> wrapper here?
Update:
We can use a construction like <template slot="activator"><slot name="activator"/></template> to throw some slot to a grand child. But what if we have multiple slots and we want to proxy them all? That's like inheritAttrs and v-bind="$attrs" for slots. Is it currently possible?
For example, there's <v-autocomplete> component in vuetify that has append, prepend, label, no-data, progress, item, selection etc slots. I write some wrapper component around this, it currently looks like:
<template>
<v-autocomplete ..>
<template slot="append"><slot name="append"/></template>
<template slot="prepend"><slot name="prepend"/></template>
<template slot="label"><slot name="label"/></template>
...
<template slot="item" slot-scope="props"><slot name="item" v-bind="props"/></template>
</v-autocomplete>
</template>
Is it possible to avoid all slots enumeration here?
If you put the slot attribute on a html element, that html element is passed to the child component to fill the slot with that name. If you don't want to pass along a html element, you can use slot on a template tag within your component. A template tag groups elements, but does not render to a html element, which is perfect here. You can use template tags also for other things, such as to group elements in a v-if for example, or to repeat multiple elements with a v-for.
// App.vue
<template>
<div id="app">
<test>
<template slot="activator">
Click <b>me</b>!
</template>
</test>
</div>
</template>
// Test.vue
<template>
<div class="wrapper">
<grand-child>
<template slot="activator">
<slot name="activator"></slot>
</template>
</grand-child>
This is some text
</div>
</template>
// GrandChild.vue
<template>
<div>
<a href="#" #click="toggle = !toggle">
<slot name="activator">Default</slot>
</a>
<div v-if="toggle">This appears and disappears</div>
</div>
</template>
Edit: If you want to do this for arbitrary slots, this is also possible. this.$slots contains the slots and their content, so with something like the following, you can pass the slot content to a slot with the same name:
<grand-child>
<template v-for="(_, slot) in $slots">
<template :slot="slot">
<slot :name="slot"></slot>
</template>
</template>
</grand-child>
For completeness sake, scoped slots can be accessed through $scopedSlots and be propagated like so:
<grand-child>
<template v-for="(_, slot) in $scopedSlots" v-slot:[slot]="props">
<slot :name="slot" v-bind="props" />
</template>
</grand-child>
source and comment
I had EsLint errors because of the depreciated :slot and $scopedSlots attributes.
So I combined both of #Sumurai8 answers like this and it works great:
<template v-for="(_, slot) in $slots" v-slot:[slot]>
<slot :name="slot"></slot>
</template>
If you have both named and unnamed slots with props:
Vue 3
<template v-for="(_, name) in $slots" #[name]="slotData">
<slot :name="name" v-bind="slotData || {}" />
</template>
Typescript version
<template v-for="(_, name) in ($slots as {})" #[name]="slotData">
<slot :name="name" v-bind="slotData || {}" />
</template>