I am in the process of learning vue and I'm stumped on how to get these buttons to dynamically style separately when clicked. These are filters for a list of products and I would like the apply one style when the filter is 'on' and a different style when the filter is 'off'. I can get the styles to update dynamically, but all of the buttons change style when any of them are clicked. The actual filter functionality is working as expected (the products are being filtered out when the button for that product is clicked).
In the code snippet, mode is passed to the BaseButton component, which is then applied as the class.
<template>
<ul>
<li v-for="genus of genusList" :key="genus.label">
<BaseButton #click="filterGenus(genus.label)" :mode="genusClicked.clicked ? 'outline' :''">
{{ genus.label }}
</BaseButton>
</li>
<BaseButton #click="clearFilter()" mode="flat">Clear Filter</BaseButton>
</ul>
</template>
methods: {
filterGenus(selectedGenus) {
this.clickedGenus = selectedGenus
this.clicked = !this.clicked
this.$emit('filter-genus', selectedGenus)
},
clearFilter() {
this.$emit('clear-filter')
}
},
I have tried making a computed value to add a .clicked value to the genusList object but that didn't seem to help.
Maybe something like following snippet (if you need more buttons to be styled at once save selected in array, if only one just save selected):
const app = Vue.createApp({
data() {
return {
genusList: [{label: 1}, {label: 2}, {label: 3}],
selGenus: [],
};
},
methods: {
isSelected(selectedGenus) {
return this.selGenus.includes(selectedGenus)
},
filterGenus(selectedGenus) {
if (this.isSelected(selectedGenus)) {
this.selGenus = this.selGenus.filter(s => s !== selectedGenus)
} else {
this.selGenus = [...this.selGenus, selectedGenus]
}
this.$emit('filter-genus', selectedGenus)
},
clearFilter() {
this.selGenus = []
this.$emit('clear-filter')
}
},
})
app.component('baseButton', {
template: `<button :class="mode"><slot /></button>`,
props: ['mode']
})
app.mount('#demo')
.outline {
outline: 2px solid red;
}
<script src="https://unpkg.com/vue#3/dist/vue.global.prod.js"></script>
<div id="demo">
<ul>
<li v-for="genus of genusList" :key="genus.label">
<base-button #click="filterGenus(genus.label)"
:mode="isSelected(genus.label) ? 'outline' :''">
{{ genus.label }}
</base-button>
</li>
<base-button #click="clearFilter()" mode="flat">
Clear Filter
</base-button>
</ul>
</div>
Related
Hello I am working with Vuejs. I am assigning class names dynamically based on my project requirement, in a loop
:class="`card-${menu.name}`"
Where menu.name can be alpha, beta,zeta etc.
Now I want to add event listener to each class differently like do a1 when click on class card-alpha, do a2 when click on class card-beta and so on. Please see that I cannot use #click="myfunc" since I want different things to be done on each different class, so its something else. Can you help me with this. Thanks a lot
Here is the code which I am using and which wont work as it only runs once when the code is mounted. So how to trigger this function everytime on click?
mounted() {
document.querySelector('.card-alpha').addEventListener('click', () => { this.$state.val = 1; });
document.querySelector('.card-beta').addEventListener('click', () => { this.$state.val = 2; });
},
You can pass value to your function, without listeners in mounted hook:
const app = Vue.createApp({
data() {
return {
items: [{id:1, name: 'alpha', val: 1}, {id:2, name: 'beta', val: 2}],
};
},
methods: {
myFunc(val) {
// do other things
// set your state with passed value
//this.$state.val = val
alert(val)
}
}
})
app.mount('#demo')
.card-beta {
color: red;
}
.card-alpha {
color: green;
}
<script src="https://unpkg.com/vue#3/dist/vue.global.prod.js"></script>
<div id="demo">
<div v-for="menu in items" :key="menu.id">
<button :class="`card-${menu.name}`" #click="myFunc(menu.val)">
{{ menu.id }}
</button>
</div>
</div>
I need to add a class to a list group create using bootstrap 5 in my vuejs app. I know about class binding but in my case I'm not sure how to proceed. I want that when the user click on an item inside the list, the clicked item get the disabled active class and the other elements gets only the disabled class. At the moment I have this code in my template
<ul class="list-group list-group-flush">
<li class="list-group-item list-group-item-action" v-for="(choice, index) in item.choices" :key="index">
<small class="" #click.prevent="checkAnswer(item.questionIndex, index)">{{ index }}) {{ choice }}</small>
</li>
</ul>
The v-for loop will generate the elements and when an element is clicked a method is called to check the user choice. In my app script I have this code
export default {
name: 'Survey',
data() {
return {
n: 0,
answeredQuestions: [],
}
},
mounted() {
},
computed: {
questions() {
return this.$store.getters.survey;
},
},
methods: {
showNext() {
if( this.n < this.questions.length ){
this.n++
}
},
isAnswered(index) {
return this.n !== index ? 'hide' : '';
},
checkAnswer(questionIndex, choice) {
this.answeredQuestions.push(true);
this.showNext();
...
}
}
}
What's the best way to implement the needed class binding?
There's a lot of unknowns about the rest of your code (how the questions are handled and switched through, etc.), but here's a working example for a single question. So you'll have to adapt this for having multiple questions in your app, but it should push you in the right direction. I used an inline :style attribute in addition to the static styles already present on the <li>, but you could move that to a function as suggeted in Peter's answer, if you prefer.
const app = {
name: 'Survey',
data() {
return {
n: 0,
questions: [],
answeredQuestions: [],
item: {
questionIndex: 1,
choices: ['Lorem', 'Ipsum']
},
selectedChoice: null
}
},
mounted() {
},
computed: {
questions() {
return this.$store.getters.survey;
},
},
methods: {
showNext() {
if (this.n < this.questions.length) {
this.n++
}
},
isAnswered(index) {
return this.n !== index ? 'hide' : '';
},
checkAnswer(questionIndex, choice) {
this.answeredQuestions.push(choice);
this.showNext();
}
}
};
Vue.createApp(app).mount('#app');
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.0.1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-+0n0xVW2eSR5OomGNYDnhzAbDsOXxcvSN1TPprVMTNDbiYZCxYbOOl7+AMvyTG2x" crossorigin="anonymous">
<script src="https://unpkg.com/vue#3.0.11/dist/vue.global.prod.js"></script>
<div id="app">
<ul class="list-group list-group-flush">
<li class="list-group-item list-group-item-action" :class="{disabled: answeredQuestions.length, active: answeredQuestions.includes(index)}" v-for="(choice, index) in item.choices" :key="index" #click.prevent="checkAnswer(item.questionIndex, index)">
<small class="">{{ index }}) {{ choice }}</small>
</li>
</ul>
</div>
If I understand correctly your situation and what you intend to do here I would suggest using the item in the checkAnswer method so that an identifier is used to set a computed property to the current item.questionIndex.
Then you bind the class of each element with a ternary operator condition to check the questionIndex and return the proper classes string: <small :class="questionIndex == item.questionIndex ? 'disabled active':'disabled'" ...
You search the internet for vue class binding and it's the first result that pops up:
https://v2.vuejs.org/v2/guide/class-and-style.html
You can use an plain object, object from your data, a function returning an object or simply a string. You can make any attribute dynamic with v-bind:, or simply :.
Your checkAnswer() function can cause a change in classes by manipulating something in data, for example.
See tutorial above for example code. Keep in mind v-bind:class is the same as :class.
The "best way" changes like every week in Vue, just find a way to do it and learn its advantages and disadvantages.
An example would be:
template: let a function generate the classes
<small
:class="getChoiceClasses(item, choice, index)"
#click.prevent="checkAnswer(item.questionIndex, index)"
>{{ index }}) {{ choice }}</small>
script: add method
getChoiceClasses(item, choice, index) {
let classes = {
active: choice == 1, // for example
disabled: false, // default
even: index % 2 == 0
};
if (whateverYouNeedToCheck) {
classes.disabled = true;
}
return classes;
}
A method is a little slower than a value from data, but it's very minor and only becomes a problem when you have 100s of calls.
I have a loop where I loop over an Array.
for each item in this array I render a new component. Now when a user clicks on a certain component I only want to add a class to that component to highlight it and remove it from others that have it. Think of it as a menu active item.
<step-icon
v-for="(step, currentStep) in steps"
/>
data() {
return {
steps: [{foo: 'bar'}, {foo2: 'bar2'}]
}
}
my step-icon.vue:
<template>
<div :class="{'selected': selected}" #click="clickStep()">
hello
</div>
</template>
data() {
return {
selected: false
}
},
methods: {
clickStep() {
this.selected = true;
}
}
This works only 1 way, I can only add the selected class but never remove it.
I created a simple example illustrating your use case since you didn't provided enough detail to go with. Below you can find the items selected and unselected. Firstly, we added a key isSelected and set it to false as default. This will act as a status for all items.
steps: [
{key:"0", tec:"foo", isSelected:false},
{key:"1", tec:"bar", isSelected:false},
{key:"2", tec:"foo2", isSelected:false},
{key:"3", tec:"bar2", isSelected:false},
]
Next, we looped over the array and displayed all the items.
<ul>
<li
v-for="l in steps"
id="l.key"
#click="select(l.key, l.isSelected)"
v-bind:class="{ selected : l.isSelected, notselected : !l.isSelected }"
> {{ l.tec }} </li>
<ul>
Here you can se we have set our status property isSelected on v-bind directive which will add or remove the class based on the value of isSelected.
Next, once the item is clicked we will trigger select method.
methods: {
select(key) {
for (let i = 0; i < this.steps.length; i++) {
if (this.steps[i].key !== key) {
this.steps[i].isSelected = false
}
}
this.toggleSelection(key)
},
toggleSelection(key) {
const stepsItem = this.steps.find(item => item.key === key)
if (stepsItem) {
stepsItem.isSelected = !stepsItem.isSelected
}
}
}
The select method will firstly unselect all those except the one which is selected and then call toggleSelection which will set the selected Item to true or false.
Complete Code:
new Vue({
el: '#app',
data: {
steps: [
{key:"0", tec:"foo", isSelected:false},
{key:"1", tec:"bar", isSelected:false},
{key:"2", tec:"foo2", isSelected:false},
{key:"3", tec:"bar2", isSelected:false},
]
},
methods: {
select(key) {
for (let i = 0; i < this.steps.length; i++) {
if (this.steps[i].key !== key) {
this.steps[i].isSelected = false
}
}
this.toggleSelection(key)
},
toggleSelection(key) {
const stepsItem = this.steps.find(item => item.key === key)
if (stepsItem) {
stepsItem.isSelected = !stepsItem.isSelected
}
}
}
})
.selected {
background: grey;
}
.notselected {
background:transparent;
}
<script src="https://unpkg.com/vue#2.6.10"></script>
<div id="app">
<ul>
<li
v-for="l in steps"
id="l.key"
#click="select(l.key, l.isSelected)"
v-bind:class="{ selected : l.isSelected, notselected : !l.isSelected }"
> {{ l.tec }} </li>
<ul>
</div>
You can keep all the step state in the parent component.
Now the parent component can listen for toggle_selected event from the nested one, and call toggle_selected(step) with the current step as a param.
Toggle_selected method should deselect all steps except the current one, and for the current one just toggle the selected prop.
If You would like to modify more props of the step in the nested component You could use .sync modifier (:step.sync="step") and then this.#emit('update:step', newStepState) in the nested component.
I've also made a snippet (my first). In this example I omitted clickStep and just put #click="$emit('toggle_selected') in the step-icon component.
new Vue({
el: '#app',
// for this example only defined component here
components: {
'step-icon': {
props: { step: Object }
}
},
data: {
steps: [
{ name: 'Alfa', selected: false},
{ name: 'Beta', selected: false},
{ name: 'Gamma', selected: false},
]
},
methods: {
toggle_selected(step) {
this.steps.filter(s => s != step).forEach(s => s.selected = false);
step.selected = true;
}
}
})
#app {
padding: 2rem;
font-family: sans-serif;
}
.step-icon {
border: 1px solid #ddd;
margin-bottom: -1px;
padding: 0.25rem 0.5rem;
cursor: pointer;
}
.step-icon.selected {
background: #07c;
color: #fff;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<!-- Ive used inline-template for this example only -->
<div id="app">
<step-icon v-for="(step, currentStep) in steps" :key="currentStep"
:step.sync="step"
#toggle_selected="toggle_selected(step)" inline-template>
<div class="step-icon"
:class="{selected: step.selected}"
#click="$emit('toggle_selected')">
{{ step.name }}
</div>
</step-icon>
</div>
I've captured the current code I have here:
https://jsfiddle.net/prsauer/Lnhu2avp/71
The basic issue is that for each click on a list item every item's computeStyle is called -- I'd prefer for each click to only produce a single recompute of the style
<div id="editor">
<div v-for="item in dungeons" :key="item.isOpened">
<div v-on:click="clickedChest(item)" v-bind:style="computeChestStyle(item)">
{{ item.name }} {{ item.isOpened }}
</div>
</div>
</div>
var dgnData = [
{ name: "Lobby", isOpened: false },
{ name: "Side", isOpened: false },
];
new Vue({
el: '#editor',
data: { dungeons: dgnData },
computed: { },
methods: {
clickedChest: chest => {
chest.isOpened = !chest.isOpened;
console.log("##### Clicked chest", chest);
},
computeChestStyle:
item => {
console.log("computeStyle", item);
return item.isOpened ? "color: red" : "color: blue";
}
}
});
Function calls get re-evaluated on every update of the view. If you want results to be cached to only re-render as needed, you need a computed. That means you need to create a component for your item, and create the computed in the component.
I am using the v-for directive to render a list .
<li v-for="group in groupList" :key="group.id" #dragenter="toggleClass ...."#dragleave="toggleClass ...." >
Content
</li>
What I want is to add a class to the li on which the dragenter event is fired ?
How can I accomplish this ?
How do I even get a reference to the item (the item,not the data property of the parent component)in the first place inside the event handle?and even If I get the reference how to toggle the class from there?
Thanks.
I know vue is data-driven , change the data to reflect on the DOM but I would like a concise solution to this rather than index/Id on the data-model based solutions.Thanks
You can access the li being dragged in the dragenter-callback by accessing event.currentTarget (or even event.target would work in this case), where event is the callback's parameter.
new Vue({
el: '#app',
data() {
return {
grouplist: [
{ id: 1, text: 'a' },
{ id: 2, text: 'b' },
{ id: 3, text: 'c' },
]
}
},
methods: {
onDragEnter(e) {
e.currentTarget.classList.add('drag-enter');
},
onDragLeave(e) {
e.currentTarget.classList.remove('drag-enter');
}
}
})
.drag-enter {
background: #eee;
}
<script src="https://unpkg.com/vue#2.5.16"></script>
<div id="app">
<p draggable>Drag this text over the list items below</p>
<ul>
<li v-for="group in grouplist"
:key="group.id"
#dragenter="onDragEnter"
#dragleave="onDragLeave">{{group.text}}</li>
</ul>
</div>