Hide Navbar component when it reaches Footer component in VueJS - vue.js

I have a fixed Navbar at the bottom and I would like to make it fade out when it meets the Footer element.
I followed this answer: Fade out Div / Section in vue.js when reaching target section
<template>
<div id="app">
<transition name="fade">
<Navbar :nav-links="navLinks" v-show="show"></Navbar>
</transition>
<router-view />
<Footer ref="footer" :nav-links="navLinks"></Footer>
</div>
</template>
<script>
import Navbar from "./components/Navbar";
import Footer from "./components/Footer";
export default {
name: "App",
components: {
Navbar,
Footer,
},
data() {
return {
show: true,
};
},
mounted() {
// this.listener = () => {
// let rect = this.$refs.footer.getBoundingClientRect();
// let top = window.innerHeight - rect.top;
// this.show = top < 0;
// };
// window.addEventListener("scroll", this.listener);
// with Intersection Observer API
this.observer = new IntersectionObserver(() => {
let rect = this.$refs.footer.getBoundingClientRect()
let top = window.innerHeight - rect.top
this.show = top < 0
})
this.observer.observe(this.$refs.footer)
},
destroyed() {
/* window.removeEventListener('scroll', this.listener) */
this.observer.unobserve(this.$refs.footer);
},
};
</script>
and it doesn't work at all.
this.listener method returns Uncaught TypeError: _this.$refs.footer.getBoundingClientRect is not a function
and
this.observer method returns TypeError: Failed to execute 'observe' on 'IntersectionObserver': parameter 1 is not of type 'Element'.
I have tried wrapping them inside $nextTick but I still get the above errors:
mounted() {
this.$nextTick(() => {
// methods here
})
},
What do you think ?

Related

Problems with $ref between parent and child component

I'm using dynamic forms to break up a long form. Beneath each dynamic form are two action buttons which, when clicked, send the user back one form set or onto the next one (unless the end of the form has been reached - the 'Next' button is replaced by a 'Submit' button).
As I have three different forms that all use the same action buttons, I decided to create a child component ('ActionButtons') for action buttons - and in doing so I've gone from code that worked to code that doesn't.
Specifically, I'm having problems with ref information involved in controlling the 'Next' button. The error message is Error in nextTick: "TypeError: Cannot read property '$v' of undefined"
The code that worked fine (i.e. before I created 'ActionButtons') is:
<template>
...
<keep-alive>
<component
ref="currentStep"
:is="currentStep"
#update="processStep"
:wizard-data="formvars"
></component>
</keep-alive>
...
<button
#click="nextButtonAction"
:disabled="!canGoNext"
class="btn"
>{{isLastStep ? 'Submit' : 'Next'}}</button>
...
</template>
<script>
import Gap2InputInfo from './Gap2InputInfo'
import Gap2Materials from './Gap2Materials'
export default {
name: 'GAP2Form',
components: {
Gap2InputInfo,
Gap2Materials
},
data () {
return {
currentStepNumber: 1,
canGoNext: false,
wizardData: {},
steps: [
'Gap2InputInfo',
'Gap2Materials',
],
formvars: {
id: 0,
purchase: null,
name: null,
quantity: null,
supplier: null,
nsteps: 0
},
updatedData: null
}
},
computed: {
isLastStep () {
return this.currentStepNumber === this.length
},
length () {
this.formvars.nsteps = this.steps.length;
return this.steps.length
},
currentStep () {
return this.steps[this.currentStepNumber - 1];
},
},
methods: {
nextButtonAction () {
if (this.isLastStep) {
this.submitForm()
} else {
this.goNext()
}
},
processStep (step) {
Object.assign(this.formvars, step.data);
this.canGoNext = step.valid
},
goBack () {
this.currentStepNumber--;
this.canGoNext = true;
},
goNext () {
this.currentStepNumber++;
this.$nextTick(() => {
this.canGoNext = !this.$refs.currentStep.$v.$invalid
})
}
}
}
</script>
In creating the child component, I send the following props to the child
<action-buttons :currentStepNumber="currentStepNumber" :canGoNext="canGoNext" :isLastStep="isLastStep" :currentStep="currentStep"></action-buttons>
and have moved the methods associated with the button actions from the parent to the child component.
My child component is:
<template>
<div>
<div id="actions" class="buttons">
<button
#click="goBack"
v-if="mcurrentStepNumber > 1"
class="btn-outlined"
>{{$t('back')}}
</button>
<button
#click="nextButtonAction"
:disabled="!canGoNext"
class="btn"
>{{isLastStep ? 'Submit' : 'Next'}}</button>
</div>
</div>
</template>
<script>
import {required} from 'vuelidate/lib/validators'
export default {
name: "ActionButtons",
props: ['currentStepNumber','canGoNext','isLastStep','currentStep'],
data: function () {
return {
mcurrentStepNumber: this.currentStepNumber,
mcurrentStep: this.currentStep,
mcanGoNext: this.canGoNext,
misLastStep: this.isLastStep
}
},
methods: {
nextButtonAction () {
if (this.misLastStep) {
this.submitForm()
} else {
this.goNext()
}
},
goBack () {
this.mcurrentStepNumber--;
this.mcanGoNext = true;
},
goNext () {
this.mcurrentStepNumber++;
this.$nextTick(() => {
this.mcanGoNext = !this.$refs.currentStep.$v.$invalid **** Error triggered at this line
})
}
}
}
</script>
Now when I click the 'Next' button, I get the Cannot read property '$v' of undefined error message. If I've interpreted it correctly, it cannot read the $refs data. I tried altering the code in the child component to
this.mcanGoNext = !this.$parent.$refs.currentStep.$v.$invalid
but the outcome remained the same. Where am I going wrong?
Thanks, Tom.

Vue: pass instantiated component to slot

I'm writing a component that renders a text. When a word starts with '#' it's a user's reference (like in twitter), and I must create a tooltip with the user's info.
This is how I instantiate the user's info component (this works fine, I'm using it in other places of the app):
const AvatarCtor = Vue.extend(AvatarTooltip);
let avatarComponent = new AvatarCtor({
propsData: {
user: user
}
});
This is the TooltipWrapper component:
<template>
<el-tooltip>
<slot name="content" slot="content"></slot>
<span v-html="text"></span>
</el-tooltip>
</template>
<script>
import {Tooltip} from 'element-ui';
export default {
name: "TooltipWrapper",
components: {
'el-tooltip': Tooltip
},
props: {
text: String
}
}
</script>
And this is how I wire it up all together:
const TooltipCtor = Vue.extend(TooltipWrapper);
const tooltip = new TooltipCtor({
propsData: {
text: "whatever"
}
});
tooltip.$slots.content = [avatarComponent];
tooltip.$mount(link);
This doesn't work. But if I set some random text in the content slot, it works fine:
tooltip.$slots.content = ['some text'];
So my problem is that I don't know how to pass a component to the slot. What am I doing wrong?
this.$slots is VNodes, but you assign with one component instance.
Below is one approach (mount the component to one element then reference its vnode) to reach the goal.
Vue.config.productionTip = false
const parentComponent = Vue.component('parent', {
template: `<div>
<div>
<slot name="content"></slot>
<span v-html="text"></span>
</div>
</div>`,
props: {
text: {
type: String,
default: ''
},
}
})
const childComponent = Vue.component('child', {
template: `<div>
<button #click="printSomething()">#<span>{{user}}</span></button>
<h4>You Already # {{this.clickCount}} times!!!</h4>
</div>`,
props: {
user: {
type: String,
default: ''
},
},
data(){
return {
clickCount: 1
}
},
methods: {
printSomething: function () {
console.log(`already #${this.user} ${this.clickCount} times` )
this.clickCount ++
}
}
})
const TooltipCtor = Vue.extend(parentComponent)
const tooltip = new TooltipCtor({
propsData: {
text: "whatever"
}
})
const SlotContainer = Vue.extend(childComponent)
const slotInstance = new SlotContainer({
propsData: {
user: "one user"
}
})
slotInstance.$mount('#slot')
tooltip.$slots.content = slotInstance._vnode
tooltip.$mount('#link')
<script src="https://unpkg.com/vue#2.5.16/dist/vue.js"></script>
<div id="link">
</div>
<div style="display:none"><div id="slot"></div></div>

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

Vuejs DOM doesn't update after fetching data

I have bound an array events to a component tag <scheduler> containing events to fill in a scheduler app (dhtmlx scheduler). However, the DOM doesn't seeem to refresh itself when data is retrieved by the getEvents methods triggered when vue instance is created.
There is 2 vue files I work with: App.vue containing the main app component and the Scheduler.vue file containing the scheduler component.
The thing is that when I modify something in the Scheduler.vue file and save it, it correctly take the updated events array into account.
Scheduler parse the data in the events prop when DOM is mounted in scheduler component.
Therefore is there something I can do to get the updated array ?
Here is the App.vue:
<template>
<div id="app">
<div class="container">
<scheduler v-bind:events="events"></scheduler>
</div>
</div>
</template>
<script>
import Scheduler from './components/Scheduler.vue';
import auth from './components/auth/index'
import data from './components/data/index'
export default {
name: 'app',
components: {
Scheduler
},
data() {
return {
events: []
}
},
created() {
this.getEvents();
},
watch: {
events: function(value) {
console.log('updated');
}
},
methods: {
async getEvents() {
try {
const token = await auth.getToken(this);
const thattoken = await auth.getThatToken(this, token);
await data.getOgustData(this, token, '/calendar/events', 307310564, this.events);
} catch (e) {
console.log(e);
}
},
}
}
</script>
Here is Scheduler.vue:
<template lang="html">
<div ref="scheduler_here" class="dhx_cal_container" style='width:100%; height:700px;'>
<div class="dhx_cal_navline">
<div class="dhx_cal_prev_button"> </div>
<div class="dhx_cal_next_button"> </div>
<div class="dhx_cal_today_button"></div>
<div class="dhx_cal_date"></div>
<div class="dhx_cal_tab" name="day_tab" style="right:204px;"></div>
<div class="dhx_cal_tab" name="week_tab" style="right:140px;"></div>
<div class="dhx_cal_tab" name="month_tab" style="right:76px;"></div>
</div>
<div class="dhx_cal_header"></div>
<div class="dhx_cal_data"></div>
</div>
</template>
<script>
import 'dhtmlx-scheduler'
import 'dhtmlx-scheduler/codebase/locale/locale_fr';
import 'dhtmlx-scheduler/codebase/ext/dhtmlxscheduler_readonly.js';
export default {
name: 'scheduler',
props: {
events: {
type: Array,
default () {
return [{
id: '',
text: '',
start_date: '',
end_date: '',
}]
}
}
},
mounted() {
scheduler.config.xml_date = '%Y-%m-%d %H:%i';
// disable left buttons on lightbox
scheduler.config.buttons_left = [];
// enable cancel button on lightbox's right wing
scheduler.config.buttons_right = ['dhx_cancel_btn'];
// changing cancel button label
scheduler.locale.labels['icon_cancel'] = 'Fermer';
// hide lightbox in month view
scheduler.config.readonly_form = true;
// hide select bar in day and week views
scheduler.config.select = false;
scheduler.config.lightbox.sections = [
{
name: "description",
height: 20,
map_to: "text",
type: "textarea",
focus: true
}
];
scheduler.init(this.$refs.scheduler_here, new Date(), 'month');
scheduler.parse(this.$props.events, 'json');
},
}
</script>
<style lang="css" scoped>
#import "~dhtmlx-scheduler/codebase/dhtmlxscheduler.css";
</style>
getOgustData can't populate events in a way that Vue can observe. Since you're passing it as an argument, the array itself can be updated, but it's not a reactive array. Try
var newEvents;
await data.getOgustData(this, token, '/calendar/events', 307310564, newEvents);
this.events = newEvents;
Assigning to this.events is something Vue can notice.
Problem is solved. The issue didn't come from Vue but rather from the dhtmlx scheduler which wasn't parsing events when events was updated.
I ended up watching for any changes to events and thus, parsing it when it updates.
Thanks again for the help provided.
App.vue :
<template>
<div id="app">
<div class="container">
<scheduler v-bind:events="events"></scheduler>
</div>
</div>
</template>
<script>
import Scheduler from './components/Scheduler.vue';
import auth from './components/auth/index'
import data from './components/data/index'
import 'dhtmlx-scheduler'
export default {
name: 'app',
components: {
Scheduler
},
data() {
return {
events: []
}
},
created() {
this.getEvents();
},
watch: {
events: function(value) {
scheduler.parse(this.events, 'json');
}
},
methods: {
async getEvents() {
const token = await auth.getToken(this);
const apiToken = await auth.getApiToken(this, token);
this.events = await data.getApiData(this, apiToken, '/calendar/events', 307310564, this.events);
}
},
}
</script>

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>