I'm making a todo app to better understand Vue and ran into a snag.
I've gone through several StackOverflow questions and the Vuejs forum, but I'm not understanding what I'm doing incorrectly.
The problem stems from the to-do-item Component Template:
<button
#click="$emit('remove-item', {{item.id}} )">
Remove
</button>
If I replace $emit with a component method that doesn't call $emit it works fine, but when I use $emit (even in a local component function) it refuses to render.
I'm not sure why this is. Here's the rest of my code:
Vue.component("todo-item", {
props:["item"],
template: `
<li>{{ item.text }}
<button
#click="$emit('remove-item', {{item.id}} )">
Remove
</button>
</li>`
})
let vm = new Vue({
el:"#app",
data: {
text: "",
todos: []
},
methods: {
getID: (function() {
let id = 0;
return function() {
return id++;
}
}()),
addTodo: function() {
this.todos.push({id: this.getID(), text: this.text});
this.text = "";
},
remove: function(remove_id) {
this.todos = this.todos.filter(({id}) => id != remove_id);
}
}
})
<script src="https://cdn.jsdelivr.net/npm/vue#2.5.17/dist/vue.min.js"></script>
<div id="app">
<div id="container">
<main>
<ul>
<todo-item
v-for="todo in todos"
:item="todo"
#remove-item="remove"
>
</todo-item>
</ul>
</main>
<div id="add-field">
<input v-model="text" /> <button id="add" #click="addTodo">Add Todo</button>
</div>
</div>
</div>
The problem is that you are trying to use template syntax inside a javascript-executed attribute:
<button
#click="$emit('remove-item', {{item.id}} )">
Fix that, and it should work:
Vue.component("todo-item", {
props:["item"],
template: `
<li>{{ item.text }}
<button
#click="$emit('remove-item', item.id )">
Remove
</button>
</li>`
})
let vm = new Vue({
el:"#app",
data: {
text: "",
todos: []
},
methods: {
getID: (function() {
let id = 0;
return function() {
return id++;
}
}()),
addTodo: function() {
this.todos.push({id: this.getID(), text: this.text});
this.text = "";
},
remove: function(remove_id) {
this.todos = this.todos.filter(({id}) => id != remove_id);
}
}
})
<script src="https://cdn.jsdelivr.net/npm/vue#2.5.17/dist/vue.min.js"></script>
<div id="app">
<div id="container">
<main>
<ul>
<todo-item
v-for="todo in todos"
:item="todo"
#remove-item="remove"
>
</todo-item>
</ul>
</main>
<div id="add-field">
<input v-model="text" />
<button id="add" #click="addTodo">Add Todo</button>
</div>
</div>
Hope this helps!
Related
isGridView: true,
isListView: true,
methods: {
switchView: function() {
this.isGridView = !this.isGridView;
},
switchData: function () {
this.isListView = !this.isListView;
}
<div class="product-grid1">item1</div>
<div class="product-grid2">item2</div>
<div class="product-grid3">item3</div>
<div class="product-list1">item1</div>
<div class="product-list2">item2</div>
<div class="product-list3">item3</div>
<div id="app-gridview">
<div>
<button class="button" v-on:click="switchView()"></button>
<button class="button" v-on:click="switchData()"></button>
</div>
<div v-bind:class="[ isGridView ? 'grid-wrapper' : 'list-wrapper' ]">
<div class="grid-row" v-if="isGridView">
<div class="grid-header" v-for="name in gridData.columns">{{ name }}</div>
</div>
<!-- GridView structure -->
<div v-if="isGridView" class="grid-row" v-for="row in gridData.data">
<div class="list-row-item" v-for="name in gridData.columns">
<div>{{ row[name] }}</div>
</div>
</div>
<!-- ListView structure -->
<div v-if="!isGridView" class="list-row" v-for="row in gridData.data">
<img v-bind:src="row.ImagePath" class="list-image" />
<div class="list-property">
<div class="list-row-item" v-for="name in gridData.columns">
<div class="list-property-name">{{ name }}</div>
<div>{{ row[name] }}</div>
</div>
</div>
</div>
</div>
I tried to implement the list and the grid view, Where I need to toggle between each one. For that i have taken isGrid and isList set to true, And from vue side i am trying to place ternary operator, And switch between each other.
Can you please help me on toggle from the list and grid view.
When you create a component whose view can be changed, I suggest that you use the container-presentational component pattern. Really easy to keep track, and it's a breeze to add a new "view" of the data.
// this is the grid view
// this is a presentational component:
// only displays what is passed through props
Vue.component("GridView", {
props: ["users"],
computed: {
headers() {
if (!this.users.length) return []
return Object.keys(this.users[0])
},
},
template: `
<table>
<thead>
<tr>
<th
v-for="header in headers"
:key="header"
>
{{ header }}
</th>
</tr>
</thead>
<tbody>
<tr
v-for="user in users"
:key="user.id"
>
<td
v-for="(val, key) in user"
:key="user.id + '-' + key"
>
{{ val }}
</td>
</tr>
</tbody>
</table>
`
})
// this is the list view
// this is a presentational component:
// only displays what is passed through props
Vue.component("ListView", {
props: ["users"],
template: `
<ol>
<li
v-for="user in users"
:key="user.id"
>
<div
v-for="(val, key) in user"
:key="user.id + '-' + key"
>
{{ key }}: {{ val }}
</div>
</li>
</ol>
`
})
// this component handles the data:
// fetching, mapping, transforming, etc.
// this is a renderless component
Vue.component("DataContainer", {
data() {
return {
users: []
}
},
mounted() {
this.fetchUsers()
},
methods: {
async fetchUsers() {
try {
const response = await fetch('https://jsonplaceholder.typicode.com/users')
const json = await response.json()
this.users = json.map(({
id,
name,
username,
email
}) => ({
id,
name,
username,
email
}))
} catch (err) {
console.error(err)
}
}
},
render(h) {
// renders nothing, just provides the data
// by passing it through "users"
return this.$scopedSlots.default({
users: this.users,
})
},
})
// the Vue instance
new Vue({
el: "#app",
data() {
return {
layout: "list-view",
}
},
methods: {
switchView() {
this.layout = this.layout === "list-view" ? "grid-view" : "list-view"
}
},
template: `
<div>
<button
#click="switchView"
>
SWITCH VIEW
</button>
<data-container>
<template
#default="{ users }"
>
<component
:is="layout"
v-bind="{ users }"
/>
</template>
</data-container>
</div>
`,
})
table {
border-collapse: collapse;
}
table,
tr,
th,
td {
border: 1px solid black;
}
td,
th {
padding: 4px 8px;
}
th {
background-color: rgba(0, 0, 0, 0.3);
}
<script src="https://cdn.jsdelivr.net/npm/vue#2.6.12/dist/vue.js"></script>
<div id="app"></div>
I understand that this is a bit further away from correcting a v-if condition-handling - but this setup would help you create flexible, extensible & maintainable solution.
I this is the cleanest solution
<template>
<button #click="toggleList">switch render view</button>
<component
:is="currentComponent"
:columns="gridData.columns"
:items="gridData.data"
/>
</template>
<script>
import gridComponent from "./your-grid-component.vue";
import listComponent from "./your-list-component.vue";
export default {
components: {
gridComponent,
listComponent,
},
data() {
return {
listType: "grid", //grid/list
gridData: {
columns: [],
data: [],
},
};
},
methods: {
toggleList() {
this.listType = this.listType === "grid" ? "list" : "grid";
},
},
computed: {
currentComponent() {
return this.listType === "grid" ? "gridComponent" : "listComponent";
},
},
};
</script>
In the following Vue Component I want to loop through dwarfs array. And as long as I am in the current component, everything is fine (TEST) and also all the following properties are correct.
Currenct_Component.vue :
<template>
<div>
<h2>Stamm: {{ tribeName }}</h2>
<div class="card-container">
<div class="card" style="width: 18rem;" v-for="dwarf in dwarfs" :key="dwarf.name">
<!-- TEST -->
<p>{{dwarf}}</p>
<!-- CHILD COMPONENT -->
<app-modal
:showModal="showModal"
:targetDwarf="dwarf"
#close="showModal = false"
#weaponAdded="notifyApp"
/>
<!-- <img class="card-img-top" src="" alt="Card image cap">-->
<div class="card-body">
<h3 class="card-title" ref="dwarfName">{{ dwarf.name }}</h3>
<hr>
<ul class="dwarf-details">
<li><strong>Alter:</strong> {{ dwarf.age }}</li>
<li><strong>Waffen:</strong>
<ul v-for="weapon in dwarf.weapons">
<li><span>Name: {{ weapon.name }} | Magischer Wert: {{ weapon.magicValue }}</span></li>
</ul>
</li>
<li><strong>Powerfactor:</strong> {{ dwarf.weapons.map(weapon => weapon.magicValue).reduce((accumulator, currentValue) => accumulator + currentValue) }}</li>
</ul>
<button class="card-button" #click="showModal = true"><span class="plus-sign">+</span> Waffe</button>
</div>
</div>
</div>
<button id="backBtn" #click="onClick">Zurück</button>
</div>
</template>
<script>
import Modal from './NewWeaponModal.vue';
export default {
data() {
return {
showModal: false,
}
},
components: { appModal : Modal },
props: ['tribeName', 'dwarfs'],
methods: {
onClick() {
this.$emit('backBtn')
},
notifyApp() {
this.showModal = false;
this.$emit('weaponAdded');
}
},
}
</script>
But when I bind the element dwarf to the Child Component <app-modal/> it changes to the next dwarf in the array dwarfs (TEST) - (So as the result when i add a new weapon in the modal-form it gets added to the second dwarf...):
Child_Component.vue :
<template>
<div>
<div class="myModal" v-show="showModal">
<div class="modal-content">
<span #click="$emit('close')" class="close">×</span>
<h3>Neue Waffe</h3>
<!-- TEST -->
<p>{{ targetDwarf }}</p>
<form>
<input
type="text"
placeholder="Name..."
v-model="weaponName"
required
/>
<input
type="number"
placeholder="Magischer Wert..."
v-model="magicValue"
required
/>
<button #click.prevent="onClick">bestätigen</button>
</form>
</div>
</div>
</div>
</template>
<script>
export default {
data() {
return {
weaponName: '',
magicValue: '',
}
},
props: ['showModal', 'targetDwarf'],
methods: {
onClick() {
if(this.weaponName !== '' &&
Number.isInteger(+this.magicValue)) {
let newData = {...this.dwarf};
newData['weapons'] = [
...this.dwarf['weapons'],
{
"name": this.weaponName,
"magicValue": Number.parseInt(this.magicValue)
},
];
this.$http.post("https://localhost:5019/api", newData)
.then(data => data.text())
.then(text => console.log(text))
.catch(err => console.log(err));
this.$emit('weaponAdded');
} else {
alert('You should fill all fields validly')
}
},
}
}
</script>
It looks like you have the <app-modal/> component inside of the v-for="dwarf in dwarfs" loop, but then the control for showing all of the modal components created by that loop is just in one variable: showModal. So when showModal is true, the modal will show each of the dwarfs, and I'm guessing the second dwarf's modal is just covering up the first one's.
To fix this, you could move the <app-modal /> outside of that v-for loop, so there's only one instance on the page, then as part of the logic that shows the modal, populate the props of the modal with the correct dwarf's info.
Something like this:
<div class="card-container">
<div class="card" v-for="dwarf in dwarfs" :key="dwarf.name">
<p>{{dwarf}}</p>
<div class="card-body">
<button
class="card-button"
#click="() => setModalDwarf(dwarf)"
>
Waffe
</button>
</div>
</div>
<!-- Move outside of v-for loop -->
<app-modal
:showModal="!!modalDwarfId"
:targetDwarf="modalDwarfId"
#close="modalDwarfId = null"
#weaponAdded="onDwarfWeaponAdd"
/>
</div>
export default {
//....
data: () => ({
modalDwarfId: null,
)},
methods: {
setModalDwarf(dwarf) {
this.modalDwarfId = drawf.id;
},
onDwarfWeaponAdd() {
//...
}
},
}
You could then grab the correct dwarf data within the modal, from the ID passed as a prop, or pass in more granular data to the modal so it's more "dumb", which is the better practice so that the component isn't dependent on a specific data structure. Hope that helps
Courtesy of #Joe Dalton's answer, a bit alternated for my case:
<div class="card" style="width: 18rem;" v-for="dwarf in dwarfs" :key="dwarf.name">
...
<button class="card-button" #click="setModalDwarf(dwarf)"><span class="plus-sign">+</span> Waffe</button>
<div>
<app-modal
:showModal="showModal"
:targetDwarf="currentDwarf"
#close="showModal = false"
#weaponAdded="notifyApp"
/>
<script>
import Modal from './NewWeaponModal.vue';
export default {
data() {
return {
showModal: false,
currentDwarf: null,
}
},
components: { appModal : Modal },
props: ['tribeName', 'dwarfs'],
methods: {
setModalDwarf(dwarf) {
this.currentDwarf = dwarf;
this.showModal = true;
},
...
}
</script>
in news.twig
{% extends 'layouts.twig' %}
{% block content %}
<section class="ls section_padding_bottom_110">
<div id="cart" class="container">
<cart
v-bind:materials="news"
type="news"
test="materials"
></cart>
<modal></modal>
</div>
<script type="text/x-template" id="modal-template">
<transition name="modal">
<div class="modal-mask" v-if="active" #click="close()">
<div class="modal-wrapper">
<div class="modal-container">
<div class="modal-header">
<h3>${ item.name }</h3>
</div>
<div class="modal-body">
${ item.body }
<br>
modal #${ item.id }
</div>
<div class="modal-footer">
<button class="modal-default-button" #click="close()">
close
</button>
</div>
</div>
</div>
</div>
</transition>
</script>
</section>
{% endblock %}
I have 2 components and 1 Vue in my js.
var Hub = new Vue();
Vue.component(
'modal', {
template: '#modal-template',
delimiters: ['${', '}'],
data: function() {
return {
active: false,
item: {
id: '',
name: '',
body: ''
}
}
},
methods: {
open: function (item) {
this.active = true;
this.item = item;
},
close: function () {
this.active = false;
}
},
mounted: function() {
this.$nextTick(function () {
Hub.$on('open-modal', this.open);
Hub.$on('close-modal', this.close);
}.bind(this));
}
});
Vue.component('cart', {
props: {
materials: { type: Array, required: true},
type: { type: String, required: true}
},
computed: {
isPoints() {
return this.type == 'paymentPoints';
},
isNews() {
return this.type == 'news';
}
},
template : `
<div class="row masonry-layout isotope_container">
<div class="col-md-4 col-sm-6 isotope-item" v-for="item in materials">
<div class="vertical-item content-padding topmargin_80">
<div class="item-media">
<img v-bind:src="item.image" alt="">
<div class="media-links p-link">
<div class="links-wrap">
<i class="flaticon-arrows-2"></i>
</div>
<a v-if="!isNews" v-bind:href="item.image" class="abs-link"></a>
</div>
</div>
<button #click="openModal(item)" #keyup.esc="closeModal()">more</button>
<div class="item-content with_shadow with_bottom_border">
<span v-if="isNews" class="categories-links" style="font-size:20px;">
<a rel="category" href="#modal1" data-toggle="modal">
{{item.name}}
</a>
</span>
<p>{{item.body}}</p>
<div v-if="isPoints">
<hr class="light-divider full-content-divider bottommargin_10">
<div class="media small-icon-media topmargin_5">
<div class="media-left">
<i class="fa fa-map-marker grey fontsize_18"></i>
</div>
<div class="media-body">
{{item.adress}}
</div>
</div>
<div class="media small-icon-media topmargin_5">
<div class="media-left">
<i class="fa fa-phone grey fontsize_18"></i>
</div>
<div class="media-body">
{{item.telephone}}
</div>
</div>
</div>
<div v-if="isNews" class="text-center">
<hr class="light-divider full-content-divider bottommargin_10">
<span class="date">
<i class="flaticon-clock-1 grey"></i>
<time class="entry-date">
{{item.date}}
</time>
</span>
</div>
</div>
</div>
</div>
</div>
`
});
var vm = new Vue({
el: '#cart',
name: 'cart',
delimiters: ['${', '}'],
data: {
complated: [],
continuing: [],
planned: [],
points: [],
infoSlider: [],
news: []
},
methods: {
openModal: function (item) {
Hub.$emit('open-modal', item);
},
closeModal: function () {
Hub.$emit('close-modal');
}
},
created() {
axios.get(url).then(res => {
var proje = res.data.projects[0];
this.complated = proje.complated;
this.continuing = proje.continuing;
this.planned = proje.planned;
this.points = res.data.paymentPoints;
this.infoSlider = res.data.sliderİnfos;
this.news = res.data.news;
})
.catch(e => {
console.log(e);
})
}
});
When I click openModal(item) button give me error ;
Property or method "openModal" is not defined on the instance but referenced during render. Make sure that this property is reactive, either in the data option, or for class-based components, by initializing the property. See: https://v2.vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.
I can not use the openModal function in component.
I can use the function in news.twig without any problems, but then I can not use the component. Can you help me?
You are using openModal in cart component, but that method is defined in root component.
According to Vue's documentation:
Everything in the parent template is compiled in parent scope;
everything in the child template is compiled in the child scope.
in my case need to define variable in vuejs
like this
<script>
export default {
name: "MegaMenu",
props: {
categories: Array,
},
}
I'm learning how to use Vue and one of the methods in my practice code isn't working, any idea why?
When clicking 'Add name' an alert should pop up, but it doesn't.
new Vue({
el: '#array',
data: {
names: ['Jo', 'Joana', 'Joanna', 'Joan']
},
methods: {
addName: function() {
alert('Adding name');
}
}
});
<script src="https://unpkg.com/vue"></script>
<div id="array">
<ul>
<li v-for="name in names" v-text="name"> {{ names }} </li>
</ul>
</div>
<input type="text">
<button v-on:click="addName">Add name</button>
Try this.
new Vue({
el: '#array',
data: {
names: ['Jo', 'Joana', 'Joanna', 'Joan'],
newName: ""
},
methods: {
addName: function() {
this.names.push(this.newName);
this.newName = ""
}
}
});
<script src="https://unpkg.com/vue"></script>
<div id="array">
<ul>
<li v-for="name in names"> {{ name }} </li>
</ul>
<input v-model="newName" type="text">
<button v-on:click="addName">Add name</button>
</div>
I have a parent component in Vue.js which looks like this:
<template>
<ul class="list-group">
<li class="list-group-item" v-for="item in items">
<div class="row">
<div class="col-md-6">
{{ item.title }}
</div>
<div class="col-md-6 text-right">
<a href="#" class="btn btn-primary btn-sm">
<span class="glyphicon glyphicon-pencil"></span>
</a>
<a href="#" class="btn btn-success btn-sm">
<span class="glyphicon glyphicon-link"></span>
</a>
<a href="#" class="btn btn-danger btn-sm">
<span class="glyphicon glyphicon-remove"></span>
</a>
</div>
<div class="col-md-12">
<preview></preview>
</div>
</div>
</li>
</ul>
</template>
The script:
<script>
import Preview from './Preview.vue';
export default {
data() {
return {
items: '',
template: []
}
},
created() {
this.fetchItems();
this.$on('preview-build', function (child) {
console.log('new preview: ')
console.log(child)
})
},
components: {
Preview
},
methods: {
fetchItems: function () {
var resource = this.$resource('api/preview');
resource.get({}).then((response) => {
this.items = response.body.item;
}, (response) => {
console.log('Error fetching tasks');
}).bind(this);
},
}
}
</script>
The child component "preview" has a template-like structure, for example {{ item.title }} again. The preview is loaded correct but it's not rendered.
I really do not know if it is possible in Vue 2.0 but hopefully someone had the same problem and can help me here.
EDIT (thanks Patrick):
<template>
<textarea rows="20" class="form-control">
{{ template.content }}
</textarea>
</template>
<script>
export default {
data() {
return {
template: [],
}
},
created() {
this.fetchTemplate();
},
methods: {
fetchTemplate: function () {
var resource = this.$resource('api/preview');
resource.get({}).then((response) => {
this.template = response.body.template;
}, (response) => {
console.log('Error fetching template');
}).bind(this);
},
}
}
</script>
This is the Preview.vue content which is similar to the Item.vue content.
As a little explanation:
The template data comes from an database as predefined html content including the {{ item.title }} and some other placeholder. I want this to be rendered with the specific stuff coming from the item.
In Vue.js, components can't directly access data from their parent. If you want preview to be able to render {{ item.title }}, you'll have to pass item down to it as a prop. So in preview.vue, declare it like this:
export default {
...
props: ['item']
}
Then, in your parent component's template, you can v-bind that item prop to something from the parent's items array:
<li class="list-group-item" v-for="item in items">
...
<preview v-bind:item="item"></preview>
...
</li>
Now your preview component has an item that it can render in its template as if it were part of the data object.