Vue - Render new component based on page count - vue.js

I'm working on an onboarding process that will collect a users name, location, job , etc.
It needs to be one question per page but as an SPA so I currently have around 20 components to conditionally render.
Atm, I have a counter and Prev/Next buttons that decrease/increase the counter respectively. I'm then using v-if to check what number the counter is on and render the appropriate page.
Is there a better way around this that is less repetitive and bulky?
Any ideas appreciated!
data() {
return {
onboardingStep: 0,
}
},
methods: {
prevStep() {
this.onboardingStep -= 1;
},
nextStep() {
this.onboardingStep += 1;
}
}
<intro-step v-if="onboardingStep === 0"></intro-step>
<first-name v-if="onboardingStep === 1"></first-name>
<last-name v-if="onboardingStep === 2"></last-name>
...etc.

Suggestion :
You can make your field components to show or hide based on the prev/next state. Dynamic components provide that platform in an efficient and simple way.
Syntax :
<component :is="componentName"></component>
Then, You can create each component instance dynamically by putting a watcher on components array.
watch: {
components: {
handler() {
this.components.forEach(cName => {
Vue.component(cName, {
template: `template code will come here`
})
});
}
}
}
Live Demo :
new Vue({
el: '#app',
data() {
return {
components: [],
onboardingStep: 0
}
},
mounted() {
this.components = ['intro-step', 'first-name', 'last-name'];
},
watch: {
components: {
handler() {
this.components.forEach(cName => {
Vue.component(cName, {
data() {
return {
modelName: cName
}
},
template: '<input type="text" v-model="modelName"/>'
})
});
}
}
},
methods: {
prevStep() {
this.onboardingStep -= 1;
},
nextStep() {
this.onboardingStep += 1;
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<div v-for="(cName, index) in components" :key="index">
<component :is="cName" v-if="index === onboardingStep"></component>
</div>
<button #click="prevStep" :disabled="onboardingStep < 1">Prev</button>
<button #click="nextStep" :disabled="onboardingStep === components.length - 1">Next</button>
</div>

You could create an array with all your component names in the right order.
const components = ['intro-step', 'first-name', 'last-name' ]
And then with a v-for loop set all the components in your template:
<template v-for="(component, index) in components" :key="component">
<component :is="component" v-if="index === onboardingStep">
</template>
Hope this helps.

Related

VUE Js child is not updating when parent updates

I am using VUE JS and I want to have group of checkboxes as below. When someone clicked on main checkbox all the checkboxes under that check box should be selected. Please find the attached image for your reference
To accomplish this scenario I am using 2 main components. When someone clicked on a component I am adding that component to selectedStreams array. Selected stream array structure is similar to below structure
checked: {
g1: ['val1'],
g2: []
}
When I click on heading checkbox I am triggering function
clickAll and try to change the selectedStreams[keyv].
But this action doesn't trigger the child component and automatically checked the checkbox.
Can I know the reason why when I changed the parent v-model value it is not visible in child UI.
Parent Component
<template>
<div>
<b-form-group>
<StreamCheckBox
v-for="(opts, keyv) in loggedInUsernamesf"
:key="keyv"
:name="opts"
:main="keyv"
v-model="selectedStreams[keyv]"
#clickAll="clickAll($event, keyv)"
></StreamCheckBox>
</b-form-group>
</div>
</template>
<script>import StreamCheckBox from "./StreamCheckBox";
export default {
name: "GroupCheckBox",
components: {StreamCheckBox},
data(){
return {
selectedStreams:{}
}
},
computed: {
loggedInUsernamesf() {
var username_arr = JSON.parse(this.$sessionStorage.access_info_arr);
var usernames = {};
if (!username_arr) return;
for (let i = 0; i < username_arr.length; i++) {
usernames[username_arr[i].key] = [];
var payload = {};
payload["main"] = username_arr[i].val.name;
payload["type"] = username_arr[i].val.type;
if (username_arr[i].val.permissions) {
for (let j = 0; j < username_arr[i].val.permissions.length; j++) {
payload["value"] = username_arr[i].key + username_arr[i].val.permissions[j].streamId;
payload["text"] = username_arr[i].val.permissions[j].streamId;
}
}
usernames[username_arr[i].key].push(payload);
}
return usernames;
},
},
methods: {
clickAll(e, keyv) {
if (e && e.includes(keyv)) {
this.selectedStreams[keyv] = this.loggedInUsernamesf[keyv].map(
opt => {
return opt.value
}
);
}
console.log(this.selectedStreams[keyv]);
}
}
}
</script>
<style scoped>
</style>
Child Component
<template>
<div style="text-align: left;">
<b-form-checkbox-group style="padding-left: 0;"
id="flavors"
class="ml-4"
stacked
v-model="role"
:main="main"
>
<b-form-checkbox
class="font-weight-bold main"
:main="main"
:value="main"
#input="checkAll(main)"
>{{ name[0].main }}</b-form-checkbox>
<b-form-checkbox
v-for="opt in displayStreams"
:key="opt.value"
:value="opt.value"
>{{ opt.text }}</b-form-checkbox>
</b-form-checkbox-group>
</div>
</template>
<script>
export default {
name:"StreamCheckBox",
props: {
value: {
type: Array,
},
name: {
type: Array,
},
main:{
type:String
}
},
computed:{
role: {
get: function(){
return this.value;
},
set: function(val) {
this.$emit('input', val);
}
},
displayStreams: function () {
return this.name.filter(i => i.value)
},
},
methods:{
checkAll(val)
{
this.$emit('clickAll', val);
}
}
}
</script>
First of all, I am not sure what is the purpose of having props in your parent component. I think you could just remove props from your parent and leave in the child component only.
Second of all, the reason for not triggering the changes could be that you are dealing with arrays, for that you could set a deep watcher in your child component:
export default {
props: {
value: {
type: Array,
required: true,
},
},
watch: {
value: {
deep: true,
//handle the change
handler() {
console.log('array updated');
}
}
}
}
You can find more info here and here.

How do I trigger a recalculation in a Vue app?

I'm working on a project with Vue and VueX. In my component, I have a calculated method that looks like this:
...mapState([
'watches',
]),
isWatched() {
console.log('check watch');
if (!this.watches) return false;
console.log('iw', this.watches[this.event.id]);
return this.watches[this.event.id] === true;
},
And in my store, I have the following:
addWatch(state, event) {
console.log('add', state.watches);
state.watches = {
...state.watches,
[event]: true,
};
console.log('add2', state.watches);
},
However, this doesn't trigger a recalculation. What's going on?
Try changing return this.watches[this.event.id] === true;
to
return this.$store.commit("addWatch", this.event.id);
The code you have shown is correct, so the problem must be elsewhere.
I assume by 'calculated method' you mean computed property.
Computed properties do not watch their dependencies deeply, but you are updating the store immutably, so that is not the problem.
Here is a bit of sample code to give you the full picture.
Add event numbers until you hit '2', and the isWatched property becomes true.
Vue.use(Vuex);
const mapState = Vuex.mapState;
const store = new Vuex.Store({
state: {
watches: {}
},
mutations: {
addWatch(state, event) {
state.watches = { ...state.watches, [event]: true };
}
}
});
new Vue({
el: "#app",
store,
data: {
numberInput: 0,
event: { id: 2 }
},
methods: {
addNumber(numberInput) {
this.$store.commit("addWatch", Number(numberInput));
}
},
computed: {
...mapState(["watches"]),
isWatched() {
if (!this.watches) return false;
return this.watches[this.event.id] === true;
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vuex/3.1.0/vuex.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<div>Watches: {{ watches }}</div>
<div>isWatched: {{ isWatched }}</div>
<br>
<input v-model="numberInput" type="number" />
<button #click="addNumber(numberInput)">
Add new event
</button>
</div>

How to build a bridge of events between different components in Vue?

I need to solve it
1) click mainMidLeft component
2) after clicked, to move slideLeftTop component
http://joxi.ru/ZrJBvERH1JVa8r
The problem I dont quite understand how to do this in right way..
Is it okay to create in mainMidLeft a method where I will do somethik like this:
move: () => {
document.querySelector(`.slideLeftTop`).style.position .....
}
The best practice is to use Vuex State manager with computed methods (getters) and watchers
I have made a working example for you on jsfiddle.
https://jsfiddle.net/n4e_m16/wujafg5e/4/
For more info on how vuex works please go to Here
Please let me know if you need more help :)
const store = new Vuex.Store({
state: {
mainMidLeftState: false,
},
getters: {
mainMidLeftState: state => state.mainMidLeftState,
},
mutations: {
toggleMainMidLeft: (state, payload) => {
state.mainMidLeftState = !state.mainMidLeftState
},
},
})
Vue.component('main-mid-left', {
data() {
return {
}
},
computed: {
mainMidLeftState() {
return this.$store.state.mainMidLeftState
},
},
methods: {
toggleMainMidLeft() {
this.$store.commit('toggleMainMidLeft')
// alert(this.mainMidLeftState)
},
}
})
Vue.component('slide-left-top', {
data() {
return {
}
},
computed: {
mainMidLeftState() {
return this.$store.state.mainMidLeftState
},
},
watch: {
mainMidLeftState: function(val) {
alert("YES, computed property changed and alert have been triggered by watcher in slide top left component")
}
},
methods: {
}
})
const app = new Vue({
el: '#app',
store,
})
div {
color: black;
}
<script src="https://unpkg.com/vue/dist/vue.js"></script>
<script src="https://unpkg.com/vuex#3.0.1/dist/vuex.js"></script>
<div id="app">
<!-- inlining the template to make things easier to read - all of below is held on the component not the root -->
<main-mid-left inline-template>
<div>
<h4>
main mid left
</h4>
<button v-on:click="toggleMainMidLeft()">toggle Main Mid Left State</button>
<div v-show="mainMidLeftState == true">State is true</div>
<div v-show="mainMidLeftState == false">State is false</div>
</div>
</main-mid-left>
<slide-left-top inline-template>
<div>
<h4>
slide left top
</h4>
<div v-show="mainMidLeftState == true">State is true</div>
<div v-show="mainMidLeftState == false">State is false</div>
</div>
</slide-left-top>
</div>
If you don't want to use vuex, you can create a new Vue instance as an event bus (I believe this is mentioned somewhere in the Vue tutorial):
const EventBus = new Vue()
Import EventBus to where you need it and you can send an event by:
EventBus.$emit('event-name', data)
And add the following script in created() of your receiver component:
EventBus.$on('event-name', ($event) => {
// Do something
})
I hope this helps |´・ω・)ノ

Fetch data in component on initiation using parameters from Vuex store

I am new to Vue and am trying to build a simple movie app, fetching data from an API and rendering the results. I want to have an incremental search feature. I have an input field in my navbar and when the user types, I want to redirect from the dashboard view to the search results view. I am unsure of how to pass the query params from the navbar to the search results view.
Here is my App.vue component
<template>
<div id="app">
<Navbar></Navbar>
<router-view/>
</div>
</template>
<script>
import Navbar from './components/Navbar.vue'
export default {
name: 'App',
components: {
Navbar
},
}
</script>
And here is my navbar component where I have the input field
<template>
<nav class="navbar">
<h1 class="logo" v-on:click="goToHome">Movie App</h1>
<input class="search-input" v-on:keyup="showResults" v-model="query" type="text" placeholder="Search..."/>
</nav>
</template>
<script>
import router from '../router/index'
export default {
data: function () {
return {
query: this.query
}
},
methods: {
goToHome () {
router.push({name: 'Dashboard'})
},
showResults () {
//here on each key press I want to narrow my results in the SearchedMovies component
}
}
}
</script>
If I use router.push to the SearchedMovies component then I am only able to pass the query as a parameter once. I thought about using Vuex to store the query and then access it from the SearchedMovies component, but surely there is a better way of doing it?
I also read about using $emit but since my parent contains all the routes, I'm not sure how to go about this.
You don't need to redirect user anywhere. I've made a small demo to show how one might do it. I used this navbar component as you described and emit an event from it:
const movies = {
data: [
{
id: 0,
title: 'Eraserhead',
},
{
id: 1,
title: 'Erazerhead',
},
{
id: 2,
title: 'Videodrome',
},
{
id: 3,
title: 'Videobrome',
},
{
id: 4,
title: 'Cube',
},
]
};
Vue.component('navbar', {
template: '<input v-model="filter" #input="onInput" placeholder="search">',
data() {
return {
filter: '',
};
},
methods: {
onInput() {
this.$emit('filter', this.filter);
}
}
});
// this is just a request imitation.
// just waiting for a second until we get a response
// from the datasample
function request(title) {
return new Promise((fulfill) => {
toReturn = movies.data.filter(movie => movie.title.toLowerCase().indexOf(title.toLowerCase()) !== -1)
setTimeout(() => fulfill(toReturn), 1000);
});
}
new Vue({
el: '#app',
data: {
movies: undefined,
loading: false,
filter: '',
lastValue: '',
},
methods: {
filterList(payload) {
// a timeout to prevent
// instant request on every input interaction
this.lastValue = payload;
setTimeout(() => this.makeRequest(), 1000);
},
makeRequest() {
if (this.loading) {
return;
}
this.loading = true;
request(this.lastValue).then((response) => {
this.movies = response;
this.loading = false;
});
}
},
mounted() {
this.makeRequest('');
}
})
<script src="https://unpkg.com/vue"></script>
<div id="app">
<navbar v-on:filter="filterList"></navbar>
<ul v-if="!loading">
<li v-for="movie in movies" :key="movie.id">{{ movie.title }}</li>
</ul>
<p v-else>Loading...</p>
</div>
Also jsfiddle: https://jsfiddle.net/oniondomes/rsyys3rp/
If you have any problem to understand the code above let me know.
EDIT: Fixed some bugs and added a couple of comments
EDIT2(after the comment below):
Here's what you can do. Every time user inputs something inside a navbar you call a function:
// template
<navbar v-on:input-inside-nav-bar="atInputInsideNavBar"></navbar>
// script
methods: {
atInputInsideNavBar(userInput) {
this.$router.push({
path: '/filtred-items',
params: {
value: userInput
}
})
}
}
Then inside you 'searched movies' page component you can access this value so:
this.$route.params.value // returns userInput from root component

Vue component data not updating from props

I'm building a SPA with a scroll navigation being populated with menu items based on section components.
In my Home.vue I'm importing the scrollNav and the sections like this:
<template>
<div class="front-page">
<scroll-nav v-if="scrollNavShown" #select="changeSection" :active-section="activeItem" :items="sections"></scroll-nav>
<fp-sections #loaded="buildNav" :active="activeItem"></fp-sections>
</div>
</template>
<script>
import scrollNav from '.././components/scrollNav.vue'
import fpSections from './fpSections.vue'
export default {
data() {
return {
scrollNavShown: true,
activeItem: 'sectionOne',
scrollPosition: 0,
sections: []
}
},
methods: {
buildNav(sections) {
this.sections = sections;
console.log(this.sections)
},
changeSection(e) {
this.activeItem = e
},
},
components: {
scrollNav,
fpSections
}
}
</script>
this.sections is initially empty, since I'm populating this array with data from the individual sections in fpSections.vue:
<template>
<div class="fp-sections">
<keep-alive>
<transition
#enter="enter"
#leave="leave"
:css="false"
>
<component :is="activeSection"></component>
</transition>
</keep-alive>
</div>
</template>
<script>
import sectionOne from './sections/sectionOne.vue'
import sectionTwo from './sections/sectionTwo.vue'
import sectionThree from './sections/sectionThree.vue'
export default {
components: {
sectionOne,
sectionTwo,
sectionThree
},
props: {
active: String
},
data() {
return {
activeSection: this.active,
sections: []
}
},
mounted() {
this.buildNav();
},
methods: {
buildNav() {
let _components = this.$options.components;
for(let prop in _components) {
if(!_components[prop].hasOwnProperty('data')) continue;
this.sections.push({
title: _components[prop].data().title,
name: _components[prop].data().name
})
}
this.$emit('loaded', this.sections)
},
enter(el) {
twm.to(el, .2, {
autoAlpha : 1
})
},
leave(el, done) {
twm.to(el, .2, {
autoAlpha : 0
})
}
}
}
</script>
The buildNav method loops through the individual components' data and pushes it to a scoped this.sections array which are then emitted back to Home.vue
Back in Home.vue this.sections is populated with the data emitted from fpSections.vue and passed back to it as a prop.
When I inspect with Vue devtools the props are passed down correctly but the data does not update.
What am I missing here? The data should react to props when it is updated in the parent right?
:active="activeItem"
this is calld "dynamic prop" not dynamic data. You set in once "onInit".
For reactivity you can do
computed:{
activeSection(){ return this.active;}
}
or
watch: {
active(){
//do something
}
}
You could use the .sync modifier and then you need to emit the update, see my example on how it would work:
Vue.component('button-counter', {
template: '<button v-on:click="counter += 1">{{ counter }}</button>',
props: ['counter'],
watch: {
counter: function(){
this.$emit('update:counter',this.counter)
}
},
})
new Vue({
el: '#counter-sync-example',
data: {
foo: 0,
bar: 0
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.2/vue.min.js"></script>
<div id="counter-sync-example">
<p>foo {{ foo }} <button-counter :counter="foo"></button-counter> (no sync)</p>
<p>bar {{ bar }} <button-counter :counter.sync="bar"></button-counter> (.sync)</p>
</div>