Vuetify: use carousel to display components - vuejs2

The response to this issue says:
The slot is missing from the docs, you can already do this.
Can someone provide a toy example or explanation of how to do this? To clarify, what I want is to import components (eg. A.vue, B.vue, C.vue) into another (eg. Carousel.vue), then display said components in a carousel. Something along the lines of:
<template>
<v-carousel>
<v-carousel-item v-for="(component, i) in components"></v-carousel-item>
</v-carousel>
</template>
<script>
import A from '#/components/A'
import B from '#/components/B'
import C from '#/components/C'
export default {
components: {
A,
B,
C
}
</script>

Issue says if you include your components properly, you can just put them inside v-carousel e.g.
<v-carousel>
<your-custom-component/>
</v-carousel>
Or inside v-carousel-item also
<v-carousel-item>
<v-btn>Hi</v-btn>
</v-carousel-item>
In order to make <your-custom-component/> work inside <v-carousel>, top level component inside <your-custom-component/> must be v-carousel-item:
// YourCustomComponent.vue
<template>
<v-carousl-item>
// ...
</v-carousl-item>
</template>
(That is unless something has changed in subsequent versions of vuetify)

Well, if you are OK with dropping the carousel requirement, then you may want to take a look at v-window. It provides exactly what you are asking for.

Related

How do I find out whether a Vue 3 component has any children?

Vue 3 removed the $children property and butchered $slots. However I can't find another solution for this scenario I'm having:
I have a component Checkbox. This component renders a checkbox. It also has a default slot. Depending on whether there was anything in that default slot I need to show/hide an element and apply some classes to the Checkbox' root element for styling and animation purposes of elements around it. I don't need access to the actual children, only the information whether there are any.
In Vue 2 I could write something like this:
if (this.$slots.default) {
// do something
}
The same thing in Vue 3 always is true, because it's a function now. However, calling that function returns nonsense:
console.log(this.$slots.default())
// Returns:
// [ Vnode ]
It doesn't matter whether I put something into the default slot or not, the end result is always the same, only with some elements buried in the Vnode tree having changed.
How am I supposed to find out whether there are any children in Vue 3?
For reference, the component template I used before:
<transition name="slide-down">
<div class="children" v-if="$slots.default">
<slot></slot>
</div>
</transition>
The above and below does not work in Vue 3 (the div always is being rendered):
<transition name="slide-down">
<div class="children" v-if="$slots.default()">
<slot></slot>
</div>
</transition>

NW.js with Vue.js how to open a link in a user's default browser?

Basically the name of the title is the question itself but let me explain.
I have a solution for this, but I think it's not practical and wants to find a better way of doing it. For example, if I want to open one link, no problem here, but if say I have tens or hundreds of links the task becomes cumbersome. Is there a neat way to solve this?
Here is the code:
<template>
<div>
<a #click.prevent="fireUpLink">External Link</a>
</div>
</template>
<script>
/* global nw */
export default {
methods: {
fireUpLink: function() {
nw.Shell.openExternal("http://example.com/");
}
}
};
</script>
In a Vue SFC, it expects a referenced variable to be defined or imported in the component, or be global. If you reference it from the global window object, it should work.
window.nw.Shell.openExternal('http://example.com');

Combining v-for with v-show on same element in template

I want to display a list of entries, and I have it working up through retrieving JSON from a server, parsing it, storing it in a Vuex.Store and iterating through it with v-for-"entry in this.$store.state.entries".
When a user first visits the page all entries will be visible. The next step is to filter the entries so that only matching entries remain visible. Since this filtering will be changing a lot, I want to use v-show. I have a separate component that lets users enter search terms, the server is queried, and an array of numbers—matching IDs—is returned. I want to only show entries with IDs that match the numbers in the array, queriedEntries. My template is below:
<template>
<div id="entries">
<div v-for="entry in this.$store.state.entries"
v-html="entry.content"
v-show="this.$store.state.queriedEntries.includes(entry.id)">
</div>
</div>
</template>
I get an error that I don't understand, and searching for answers hasn't yielded anything because it doesn't match the problem others have had.
[Vue warn]: Error in render: "TypeError: this is undefined"
It's the this in the v-show, but every other this works. What's up?
Your problem is occurring because you are referencing this inside your template. This is not necessary.
The first thing I recommend you do is have a read into Vuex' Getters. Further down on the same page, you'll find information about mapGetters. This will help to prevent you from directly targeting/modifying data within your state. Modification of data should be left only to Mutations and Actions.
For example, your code may look like the below:
// in your component script
...
import { mapState } from 'vuex'
export default {
computed: {
...mapState({
allEntries: 'entries', // map state.entries to the name 'allEntries'
queriedEntries, // your other state value. You may want to convert this to a getter
// other state values if necessary
})
}
}
...
// in your component template
<template>
<div id="entries">
<div v-for="entry in allEntries"
v-html="entry.content"
v-show="queriedEntries.includes(entry.id)">
</div>
</div>
</template>
...
Here you can see that we have used mapState which helpfully generates computed getter functions from our data in the store. We can then use the property name we have assigned it to within our template.
I ended up removing this from everything but the v-for, as suggested, and the code worked. Why this causes an error in v-show and v-html is still a mystery.
Final, working code:
<div v-for="(entry, entryindex) in this.$store.state.entries"
v-bind="{id:entryindex}"
v-bind:key="entryindex"
v-show="$store.state.queryMatchedEntries[0] == -1 || $store.state.queryMatchedEntries.indexOf(parseInt(entryindex)) != -1">

Best way to load page data into div with VueJS

I have been doing a lot of VueJS tutorials including the router, event bus, and trying to use fetchival and axios to no avail.
The setup, I want there to be two sections. One where I have buttons and the second section would be updated with html data from html files that varies depending on the button pressed.
I have used event bus to be able to just update the second div with basic, static html
(i.e. <p>got it</p>) but I cannot, for the life of me, use any request to get html from another website or file and load it into the div.
I don't necessarily need anyone to build it for me, but even some guidance and direction would be infinitely appreciated.
Based on your comments above, I think you want to change your thinking from "loading html files" to "showing different parts of the Vue component."
Here's a basic example. I'm going to use Vue single-file component syntax, but it's not hard to refactor for class-based components:
<template>
<div>
<button #click="clickedShowFirst">Show First</button>
<button #click="clickedShowSecond">Show Second</button>
<div v-if="showingFirst">
This is the first section!
</div>
<div v-else>
This is the second section!
</div>
</div>
</template>
<script>
export default {
data: function () {
return {
// We default to showing the first block
showingFirst: true
}
}
methods: {
clickedShowFirst: function () {
this.showingFirst = true
},
clickedShowSecond: function () {
this.showingFirst = false
}
}
}
</script>
You could of course make each of the v-if blocks components of their own that you import (which makes sense if they are complex themselves).
Or as suggested by Phillipe, you can use vue-router and make each of those views a different page with a different URL.
One last recommendation to leave you with, I found Jeffrey Way's Laracasts series on Vue.js amazingly helpful when I was learning. His episode titled "Exercise #3: Tabs" is very similar to what you're asking here.
You could use vue-router (https://router.vuejs.org/en/). In first section put the router-link (https://router.vuejs.org/en/api/router-link.html), your buttons, in second section put the router-view (https://router.vuejs.org/en/api/router-view.html).

Use cases for vue.js directive vs component?

When should I use a directive vs a component in vue.js? I'm implementing some stuff from Bootstrap and it looks like I could do it either way (I'm starting with the dropdown menu).
I get the feeling that a directive is more for manipulating the dom on a single element, while components are for packaging a bunch of data and/or dom manipulation. Is this a good way to look at it?
This Stack Overflow question is the #1 result to the Google query "vue directive vs component". Saurshaz’s answer is currently the accepted one and it’s very wrong in Vue 2.0. I imagine this is leading a lot of people astray so I'm going to weigh in here.
The answer to “should I use a directive or a component in Vue” is almost always a component.
Do you want to have reusable HTML? I.e. reusable widgets? Then use a component. Do you want two of these widgets to have discrete data? Then use a component. The data of one will NOT override the data of another. Maybe that was true in Vue 1.0, I don't know. But it's absolutely not true in Vue 2.0. In Vue 2.0, your components have a data function that returns a unique set of data. Consider this real-life of a Vue dropdown that has an HTML markup similar to the UI Bootstrap dropdown:
<template>
<span class="dropdown sm-dropdown" #click="toggle" :class="{'open': isOpen}">
<a class="dropdown-toggle">
<span class="special-field">{{ label }}</span>
</a>
<ul class="dropdown-menu">
<li v-for="choice in choices">
<a #click.prevent="click(choice)">{{ choice.label }}</a>
</li>
</ul>
</span>
</template>
<script>
export default {
name: 'Dropdown',
props: ['label', 'options', 'onChange'],
data() {
return {
choices: this.options,
isOpen: false
}
},
methods: {
click(option) {
this.onChange(option);
},
toggle() {
this.isOpen = !this.isOpen;
}
}
}
</script>
Now in a parent component, I can do something like this:
<template>
<div class="container">
<dropdown
label="-- Select --"
:options="ratingChoices"
:onChange="toggleChoice"
>
</dropdown>
<dropdown
label="-- Select --"
:options="ratingChoices"
:onChange="toggleChoice"
>
</dropdown>
</div>
</template>
<script>
import Dropdown from '../dropdown/dropdown.component.vue';
export default {
name: 'main-directive',
components: { Dropdown },
methods: {
toggleChoice(newChoice) {
// Save this state to a store, e.g. Vuex
}
},
computed: {
ratingChoices() {
return [{
value: true,
label: 'Yes'
}, {
value: false,
label: 'No'
}]
}
}
}
</script>
There's a decent amount of code here. What's happening is we're setting up a parent component and inside that parent component we have two dropdowns. In other words, the dropdown component is being called twice. The point I'm trying to make in showing this code is this: when you click on the dropdown, the isOpen for that dropdown changes for that directive and for that directive only. Clicking on one of the dropdowns does not affect the other dropdown in any way.
Don't choose between components or directives based on whether or not you're wanting discrete data. Components allow for discrete data.
So when would you want to choose a directive in Vue?
Here are a couple of guidelines that'll hopefully get you thinking in the right direction.
You want to choose a directive when you're wanting to extend the functionality of HTML components and you suspect that you’re going to need this extendability across multiple components and you don't want your DOM to get deeper as a result. To understand what I mean by this, let's look at the directives that Vue provides out of the box. Take its v-for directive for instance. It allows you to loop through a collection. That's very useful and you need to be able to do that in any component you want, and you don't want the DOM to get any deeper. That's a good example of when a directive is the better choice.[1]
You want to choose a directive when you want a single HTML tag to have multiple functionality. For example, an element that both triggers an Ajax request and that has a custom tooltip. Assuming you want tooltips on elements other than Ajax-triggering elements, it makes sense to split these up into two different things. In this example I would make the tooltip a directive and the Ajax feature driven by a component so I could take advantage of the built-in #click directive that’s available in components.
1 A footnote for the more curious. In theory v-for could have been made as a component, but doing so would have required a deeper-than-necessary DOM every time you wanted to use v-for as well as a more awkward syntax. If Vue had chosen to make a component out of it, instead of this:
<a v-for="link in links" :href="link.href">link.anchor</a>
The syntax would have had to have been this:
<v-for items="link in links">
<a :href="link.href">link.anchor</a>
</v-for>
Not only is this clumsy, but since the component code would have needed to implement the <slot></slot> syntax in order to get the innerHTML, and since slots cannot be immediate children of a <template> declaration (since there's no guarantee that slot markup has a single node of entry at its top level), this means there would have to be a surrounding top-level element in the component definition for v-for. Hence the DOM would get deeper than necessary. Directive was unequivocally the right choice here.
I think of it this way:
Components define widgets - these are sections of html that have behavior associated with them.
Directives modify behavior of sections of html (which may or may not be widgets).
I think this difference is better explained with two examples.
Components: are wrappers that are best suited when you need to insert (or add) your own HTML tags over something to render it. E.g. a widget, a custom button, etc where you would need to add some HTML tags to show it properly.
Directives: don't add tags but rather give you direct access to the HTML tag (to which you have added the directive). This gives you access to modify the attributes of that HTML element directly. E.g. initializing a tooltip, set css styles, bind to an event, etc.
Reusability is a reason for using directives,
While Components are also creating reusable 'widgets', two components in the same html system would overwrite the previous ones 'data', So think of directives in a case like this.
Another point worth thinking of is - Can user be using it via HTML only after some instructions ?