VUE Js child is not updating when parent updates - vue.js

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.

Related

Vue - Render new component based on page count

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.

How to set dynamic value in variable or connect two variable Vue

I have an array with a variable ecoveneer_magma_oak that I want to change by pressing a button.
When I change the variable in console, everything is good but I don't see my value on the page.
PS: I am a beginner in Vue.
Here is my code
<template>
<div>
<swiper-slide
v-for="door in doors"
:key="door.id"
class="card"
:door="doors"
></swiper-slide>
<div class="modelName">{{ door.model }}</div>
</div>
</template>
<script>
export default {
data() {
return {
ecoveneer_magma_oak: 'Дуб Магма',
doors: [
{
image: '1.jpg',
model: '018 BG',
ecoveneer_magma_oak: 'Дуб Бордо',
decor: this.ecoveneer_magma_oak,
id: '1',
},
],
}
},
methods: {
changeLange(lang) {
this.ecoveneer_magma_oak = 'Ecoveneer Magma Oak'
},
},
}
</script>
Ok I have spend 2 work days for find answer but nothing Now I declare variable not in data then I change variable and refresh DOM but variable "decor" not changing
var ecoveneer_magma_oak= 'Дуб Бордо'
export default {
data() {
doors: [
{
image:"1.jpg",
model:"018 BG",
decor: ecoveneer_magma_oak,
id:"1"
}],
methods: {
changeLange(lang){
if(lang==='RU'){
this.renderComponent = false;
this.$nextTick(() => {
// Add the component back in
this.renderComponent = true;
});
ecoveneer_magma_oak="Ecoveneer Magma Oak"
}
}

How to create a method with props passed to child component (Vue3)

I am struggling on the last part of my starter project with outputting the results onto its own component.
I have created a method in the parent component to push the results to an array, and I am then passing that array as props to the child component.
If I just display the array in my child component it works fine, however what I am trying to do is then create a method in my child component based on the results passed via the props.
When I try to do this I am not getting anything outputted, is this something which you can do in Vue?
Parent:
<template>
<button #click="decreaseCount">Decrease</button>
<button #click="increaseCount">Increase</button>
<div class="counterDiv">Counter: {{ count }}</div>
<button #click="calculateResults">Submit</button>
<results v-if="resultsVisible" :results="results"></results>
</template>
<script>
import Results from "./components/Results.vue";
export default {
name: "App",
components: {
Results,
},
data() {
return {
count: 0,
results: [],
resultsVisible: false,
};
},
methods: {
increaseCount() {
this.count += 1;
},
decreaseCount() {
this.count -= 1;
},
calculateResults() {
this.results.push(this.count);
this.resultsVisible = true;
},
},
};
</script>
Child:
<template>
<div class="finalResults">Results: {{ this.resultsText }}</div>
</template>
<script>
export default {
props: ["results"],
data() {
return {
resultsText: "",
};
},
methods: {
returnText() {
if (results < 10) {
this.resultsText = "Below 10";
}
},
},
};
</script>
I have created a very basic example of my problem below
You should emit a custom event from child component which has as handler the parent method:
child :
<template>
<div class="finalResults">Results: {{ this.resultsText }}</div>
</template>
<script>
export default {
props: ["results"],
data() {
return {
resultsText: "",
};
},
methods: {
returnText() {
if (this.results < 10) {
this.resultsText = "Below 10";
this.$emit('push-item', this.resultsText )
}
},
},
};
</script>
in parent component :
<results v-if="resultsVisible" :results="results" #push-item="pushResult"></results>
...
methods:{
pushResult(resulttext){...}
....
}

vue js sync modifier doesn't update the input value

I have a beginner question about sync modifier in vuejs. In my example, i want to change the value of inputs depending on focus event. The value is an Object inputsData and i'm getting it from the app. In parent i'm passing it to the child where it is rendering. I set an timer because i want to emit an server request. As you can see in the handleFocusFromChild Methode it change me the dataToBeChanged with newData (se also log after 4 seconds). As i understood from vue guid it should to update also the input value but it doens't, and i don't understand why, because dataToBeChanged have now the new values from newData. Can someone explain me why and how should i do to make it work?
Here i'm using the the Parent:
import Parent from "./parent.js";
Vue.component("app", {
components: {
Parent
},
template: `
<div>
<parent :inputsData="{
'firstElement':{'firstInputValue':'Hi there'},
'secondElement':{'secondInputValue':'Bye there'}
}"></parent>
</div>
`
});
Here is the Parent:
import Child from "./child.js";
export default {
name: "parent",
components: {
Child
},
props: {
inputsData: Object
},
template: `
<div>
<child #focusEvent="handleFocusFromChild"
:value.sync="inputsData.firstElement.firstInputValue"></child>
<child #focusEvent="handleFocusFromChild"
:value.sync="inputsData.secondElement.secondInputValue"></child>
</div>
`,
computed: {
dataToBeChanged: {
get: function() {
return this.inputsData;
},
set: function(newValue) {
this.$emit("update:inputsData", newValue);
}
}
},
methods: {
handleFocusFromChild: function() {
var newData = {
firstElement: { firstInputValue: "Hi there is changed" },
secondElement: { secondInputValue: "Bye there is changed" }
};
setTimeout(function() {
this.dataToBeChanged = newData;
}, 3000);
setTimeout(function() {
console.log(this.dataToBeChanged);
}, 4000);
}
}
};
Here is the child:
export default {
template: `
<div class="form-group">
<div class="input-group">
<input #focus="$emit('focusEvent', $event)"
v-model="value">
</div>
</div>
`,
props: {
value: String
}
};
you child component should emit "this.$emit('update:value', newValue)" as event
take a look over the docs: https://br.vuejs.org/v2/guide/components-custom-events.html
Also a way to do it is like this:
export default {
template: `
<div class="form-group">
<div class="input-group">
<input #focus="$emit('focusEvent', $event)"
v-model="valueProp">
</div>
</div>
`,
props: {
value: String
},
computed: {
valueProp:{
get(){
return this.value
},
set(val){
return this.$emit("update:value", val);
}
},
}
methods: {
handleFocus() {
this.$emit("focusEvent");
}
}
};

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>