Vue.js routing no method handled - javascript

I get some trouble with Vue.js and his routing system. I made an example here.
Why the method is correctly attach when I use a template (see Foo) and why not when I use an el (see Bar) ?
Here his the code:
index.js
var Foo = Vue.extend({
template: '<p v-on:click.prevent="foo">This is foo!</p>',
methods: {
foo: function(){
alert('YEAH')
}
}
})
var Bar = Vue.extend({
el: function(){
return '#bar'
},
methods: {
bar: function(){
alert('YEAH')
}
}
})
var App = Vue.extend({})
var router = new VueRouter()
router.map({
'/foo': {
component: Foo
},
'/bar': {
component: Bar
}
})
router.start(App, '#app')
index.html
<div id="app">
<h1>Hello App!</h1>
<p>
<!-- use v-link directive for navigation. -->
<a v-link="{ path: '/foo' }">Go to Foo</a>
<a v-link="{ path: '/bar' }">Go to Bar</a>
</p>
<div id="bar" v-bind:class="$route.path == '/bar' ? '' : 'hidden'">
<p v-on:click.prevent="bar">This is bar!</p>
</div>
<!-- use router-view element as route outlet -->
<router-view></router-view>
</div>

You misunderstood the el purpose. When you pass el to component it tells Vue on which element to mount itself
Note that the provided element merely serves as a mounting point; it will be replaced if a template is also provided, unless replace is set to false. The resolved element will be accessible as vm.$el.
Actually you have no template inside #bar that Vue could compile and that's why you have no output. Also using el inside another Vue's el (in your case #app) is a bad idea. The v-on:click.prevent="bar" bit is compiled in parent's (App instance) scope, and since App has no bar method you get a warning.
Better solution:
http://codepen.io/anon/pen/zqWKrg
Notice that now each component has it's own template and you can clearly see scope of each component: #app is compiled in App scope, #foo is compiled in Foo scope and #bar is compiled in Bar scope.

you should use template: '#bar' instead of el: '#bar' the el option is not a selector for the template.
var Bar = Vue.extend({
template: '#bar',
methods: {
bar: function(){
alert('YEAH')
}
}
})
You (ab)used a regular HTML element in the Apps main template as a sub-template for a component - that's not something you should do.
Its also the reason the click event is not working: the content of that div, including the click event, is evaluated by the App component, not the Bar component. And the App component has no "bar" method.
Hence the error in the console:
[Vue warn]: v-on:click="bar" expects a function value, got undefined
The template should look like this:
<script type="x-template" id="bar">
<div>
<p v-on:click.prevent="bar">This is bar!</p>
</div>
</script>
<!-- or with HTML5 template tag: -->
<template id="bar">
<div>
<p v-on:click.prevent="bar">This is bar!</p>
</div>
</template>

Related

Get template as string in Vue

Say, I have the following single file component in Vue:
// Article.vue
<template>
<div>
<h1>{{title}}</h1>
<p>{{body}}</p>
</div>
</template>
After importing this component in another file, is it possible to get its template as a string?
import Article from './Article.vue'
const templateString = // Get the template-string of `Article` here.
Now templateString should contain:
<div>
<h1>{{title}}</h1>
<p>{{body}}</p>
</div>
It is not possible.
Under the hood, Vue compiles the templates into Virtual DOM render functions.
So your compiled component will have a render function, but no place to look at the string that was used to generate it.
Vue is not a string-based templating engine
However, if you used a string to specify your template, this.$options.template would contain the string.
set ref attribute for your component, and then you can get rendered HTML content of component by using this.$refs.ComponentRef.$el.outerHTML, and remember don't do this when created.
<template>
<div class="app">
<Article ref="article" />
</div>
</template>
<script>
import Article from './Article.vue'
export default {
name: 'App',
data() {
return {
templateString: ""
}
},
components: {
Article,
},
created() {
// wrong, $el is not exists then
// console.log(this.$refs.article.$el.outerHTML)
},
mounted() {
this.templateString = this.$refs.article.$el.outerHTML
},
}
</script>

Vue Router. Bind data

I am developing vue app and now I am on step when I should use vue router.
But I have a little problem with data bind into router template.
Please help me.
HTML:
<div id="app">
<h1>Hello App!</h1>
<p>
<router-link to="/foo">Go to Foo</router-link>
<router-link to="/bar">Go to Bar</router-link>
</p>
<router-view></router-view>
</div>
Script:
const Foo = { template: '<div>{{foo}}</div>' }
const Bar = { template: '<div>bar</div>' }
const routes = [
{ path: '/foo', component: Foo },
{ path: '/bar', component: Bar }
]
const router = new VueRouter({
routes
})
const app = new Vue({
el: '#app',
router,
data: function(){
return {foo: "asdasdas"}
}
})
{{foo}} bind doesn't work.
Live example:
https://jsfiddle.net/xgrjzsup/4430/
From the guide on components :
Every component instance has its own isolated scope. This means you
cannot (and should not) directly reference parent data in a child
component’s template. Data can be passed down to child components
using props.
and Foo is a child component of your app set via the router.
One way to pass data from parent to child is to use props.
Modify your Foo definition to accept a foo property:
const Foo = {
props: ['foo'],
template: '<div>{{foo}}</div>'
}
and bind the parent property in the template
<router-view :foo="foo"></router-view>
An updated Fiddle : https://jsfiddle.net/xgrjzsup/4431/
in your case there are two ways you can access that "foo" var.
{{$parent.foo}}
{{$root.foo}}
But consider using Vuex for sharing data in your application - https://github.com/vuejs/vuex
Or pass that foo as a parameter to the route -https://router.vuejs.org/en/essentials/passing-props.html
Ofc it does not work. you have to set the data on the template you use.
in your case:
const Foo = {
template: '<div>{{foo}}</div>',
data () {
return {
foo: 'magic'
}
}
}
Cheers and happy coding.

Vue instance inside Vue instance

Sup people!
I got this HTML code here:
// index.html
<div data-init="component-one">
<...>
<div data-init="component-two">
<button #click="doSomething($event)">
</div>
</div>
This basically references a Vue instance inside another Vue instance if I understood everything correctly. The respective JS code is split up in two files and looks like this:
// componentOne.js
new Vue(
el: '[data-init="component-one"]',
data: {...},
methods: {...}
);
// componentTwo.js
new Vue(
el: '[data-init="component-two"]'
data: {...}
methods: {
doSomething: function(event) {...}
}
);
Now, the problem with this is, that doSomething from componentTwo never gets called.
But when I do some inline stuff, like {{ 3 + 3 }}, it gets computed like it should. So Vue knows there is something. And it also removes the #click element on page load.
I tried fiddling around with inline-template as well, but it doesn't really work as I'd expect it to in this situation. And I figured it isn't meant for this case anyway, so I dropped it again.
What would the correct approach be here? And how can I make this work the easiest way possible with how it's set up right now?
The Vue version we use is 2.1.8.
Cheers!
The problem is that you have two vue instances nested to each other.
If the elements are nested, then you should use the same instance or try components
https://jsfiddle.net/p16y2g16/1/
// componentTwo.js
var item = Vue.component('item',({
name:'item',
template:'<button #click="doSomething($event)">{{ message2 }</button>',
data: function(){
return{
message2: 'ddddddddddd!'
}},
methods: {
doSomething: function(event) {alert('s')}
}
}));
var app = new Vue({
el: '[data-init="component-one"]',
data: {
message: 'Hello Vue!'
}
});
<div data-init="component-one">
<button >{{ message }}</button>
<item></item>
</div>
Separate instances work if they are independant of each other.
as follows:
https://jsfiddle.net/p16y2g16/
var app = new Vue({
el: '[data-init="component-one"]',
data: {
message: 'Hello Vue!'
}
});
// componentTwo.js
var ddd = new Vue({
el: '[data-init="component-two"]',
data: {
message: 'ddddddddddd!'
},
methods: {
doSomething: function(event) {alert('s')}
}
});
But when I do some inline stuff, like {{ 3 + 3 }}, it gets computed like it should. So Vue knows there is something.
Because you have parent instance 'componentOne'. It activated Vue for this template. If you need to set another instance inside, you have to separate part of template. Example (it can lag in snippet!) .
Alternative
https://jsfiddle.net/qh8a8ebg/2/
// componentOne.js
new Vue({
el: '[data-init="component-one"]',
data: {
text: 'first'
},
methods: {}
});
// componentTwo.js
new Vue({
el: '[data-init="component-two"]',
data: {
text: 'second'
},
template: `<button #click="doSomething($event)">{{text}}</button>`,
methods: {
doSomething: function(event) {
console.log(event);
}
}
});
<script src="https://vuejs.org/js/vue.min.js"></script>
<div data-init="component-one">
{{text}}
</div>
<div data-init="component-two">
</div>
The button element inside component-two is referenced as a slot in Vue.
The evaluation of the #click directive value happens in the parent component (component-one, which host component-two). Therefor, you need to declare the click handler over there (over component-one).
If you want the handler to be handled inside component-two, you should declare a click directive for the slot element in it's (component-two) template, and pass the handler function, for instance, as a pop.
good luck.
You're doing everything right except you've nested the 2nd Vue instance inside the 1st. Just put it to the side and it will work as expected.
Vue ignores binding more than once to the same element to avoid infinite loops, which is the only reason it doesn't work nested.
Use vue-cli to create a webpack starter app. vue init app --webpack
Then, try to structure your components this way. Read more: https://v2.vuejs.org/v2/guide/components.html#What-are-Components
This is main.js
import Vue from 'vue'
import ComponentOne from './ComponentOne.vue'
import ComponentTwo from './ComponentTwo.vue'
new Vue({
el: '#app',
template: '<App/>',
components: {
ComponentOne,
ComponentTwo
}
})
This is ComponentOne.vue
<template>
<div class="user">
<div v-for="user in users">
<p>Username: {{ user.username }}</p>
</div>
</div>
</template>
<script>
export default {
data () {
return {
users: [
{username: 'Bryan'},
{username: 'Gwen'},
{username: 'Gabriel'}
]
}
}
}
</script>
This is ComponentTwo.vue
<template>
<div class="two">
Hello World
</div>
</template>
<script>
export default {
}
</script>
<div th:if="${msg.replyFloor}">
<div class="msg-lists-item-left">
<span class="msg-left-edit"
th:classappend=" ${msg.unreadCount == 0} ? 'msg-all-read' ">您在</span>
<span th:text="${msg.topic.title}"
class="msg-left-edit-res"
th:classappend=" ${msg.unreadCount == 0} ? 'msg-all-read' ">问题回答</span>
<span th:text="${msg.type.name}"
class="msg-left-edit "
th:classappend=" ${msg.unreadCount == 0} ? 'msg-all-read' ">帖子相关</span>
<span class="msg-left-edit-number" >
产生了<span th:text="${msg.unreadCount} ? : ${msg.unreadCount} + '条新' : ${msg.unreadCount} + '条' "
th:class="${msg.unreadCount} ? : 'number-inner':''">2132条</span>回复
</span>
</div>
<div class="msg-lists-item-right">
<span th:text="${msg.lastShowTime}">2017-8-10</span>
</div>
</div>

vue.js list ( template ) binding not updating when changing data from directive

First of all : I'm using laravel spark and the given setup of vue that comes with spark.
I have a "home" component with the prop "custom". Within custom there's a "passwords" array. (Entry added by code of directive, it's initialized empty)
My component ( alist) which should be bound against the data
<template id="passwords-list-template">
<div class="password" v-for="password in list">
<ul>
<li>{{ password.name }}</li>
<li>{{ password.description }}</li>
</ul>
</div>
</template>
<script>
export default {
template: '#passwords-list-template',
props: ['list'],
};
</script>
Usage
<passwords-list :list="custom.passwords"></passwords-list>
Using vue devtools I can see that my data is updating, however my list is not. Also other bindings like
<div v-show="custom.passwords.length > 0">
Are not working ...
UPDATE : Parent component (Home)
Vue.component('home', {
props: ['user', 'custom'],
ready : function() {
}
});
Usage
<home :user="user" :custom="spark.custom" inline-template>
Update 2: I played around a little bit using jsfiddle. It seems like changing the bound data object using $root works fine for me when using a method of a component. However it does not work when trying to access it using a directive
https://jsfiddle.net/wa21yho2/1/
There were a lot of errors in your Vue code. First of all, your components where isolated, there wasn't an explicit parent-child relationship.Second, there were errors in the scope of components, you were trying to set data of the parent in the child, also, you were trying to set the value of a prop, and props are by default readonly, you should have written a setter function or change them to data. And finally, I can't understand why were you trying to use a directive if there were methods and events involve?
Anyway, I rewrote your jsfiddle, I hope that you find what you need there. The chain is Root > Home > PasswordList. And the data is in the root but modified in home, the last component only show it. the key here are twoWay properties, otherwise you wouldn't be able to modify data through properties.
Here is a snippet of code
Home
var Home = Vue.component('home', {
props: {
user: {
default: ''
},
custom: {
twoWay: true
}
},
components: {
passwordList: PasswordList
},
methods: {
reset: function () {
this.custom.passwords = [];
}
}
});
// template
<home :custom.sync="spark.custom" inline-template>
{{custom | json}}
<button #click="reset">
reset in home
</button>
<password-list :list="custom.passwords"></password-list>
<password-list :list="custom.passwords"></password-list>
</home>
Here is the full jsfiddle

Call a Vue.js component method from outside the component

Let's say I have a main Vue instance that has child components. Is there a way of calling a method belonging to one of these components from outside the Vue instance entirely?
Here is an example:
var vm = new Vue({
el: '#app',
components: {
'my-component': {
template: '#my-template',
data: function() {
return {
count: 1,
};
},
methods: {
increaseCount: function() {
this.count++;
}
}
},
}
});
$('#external-button').click(function()
{
vm['my-component'].increaseCount(); // This doesn't work
});
<script src="http://vuejs.org/js/vue.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="app">
<my-component></my-component>
<br>
<button id="external-button">External Button</button>
</div>
<template id="my-template">
<div style="border: 1px solid; padding: 5px;">
<p>A counter: {{ count }}</p>
<button #click="increaseCount">Internal Button</button>
</div>
</template>
So when I click the internal button, the increaseCount() method is bound to its click event so it gets called. There is no way to bind the event to the external button, whose click event I am listening for with jQuery, so I'll need some other way to call increaseCount.
EDIT
It seems this works:
vm.$children[0].increaseCount();
However, this is not a good solution because I am referencing the component by its index in the children array, and with many components this is unlikely to stay constant and the code is less readable.
In the end I opted for using Vue's ref directive. This allows a component to be referenced from the parent for direct access.
E.g.
Have a component registered on my parent instance:
var vm = new Vue({
el: '#app',
components: { 'my-component': myComponent }
});
Render the component in template/html with a reference:
<my-component ref="foo"></my-component>
Now, elsewhere I can access the component externally
<script>
vm.$refs.foo.doSomething(); //assuming my component has a doSomething() method
</script>
See this fiddle for an example: https://jsfiddle.net/0zefx8o6/
(old example using Vue 1: https://jsfiddle.net/6v7y6msr/)
Edit for Vue3 - Composition API
The child-component has to return the function in setup you want to use in the parent-component otherwise the function is not available to the parent.
Note: <sript setup> doc is not affacted, because it provides all the functions and variables to the template by default.
You can set ref for child components then in parent can call via $refs:
Add ref to child component:
<my-component ref="childref"></my-component>
Add click event to parent:
<button id="external-button" #click="$refs.childref.increaseCount()">External Button</button>
var vm = new Vue({
el: '#app',
components: {
'my-component': {
template: '#my-template',
data: function() {
return {
count: 1,
};
},
methods: {
increaseCount: function() {
this.count++;
}
}
},
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<my-component ref="childref"></my-component>
<button id="external-button" #click="$refs.childref.increaseCount()">External Button</button>
</div>
<template id="my-template">
<div style="border: 1px solid; padding: 2px;" ref="childref">
<p>A counter: {{ count }}</p>
<button #click="increaseCount">Internal Button</button>
</div>
</template>
For Vue2 this applies:
var bus = new Vue()
// in component A's method
bus.$emit('id-selected', 1)
// in component B's created hook
bus.$on('id-selected', function (id) {
// ...
})
See here for the Vue docs.
And here is more detail on how to set up this event bus exactly.
If you'd like more info on when to use properties, events and/ or centralized state management see this article.
See below comment of Thomas regarding Vue 3.
You can use Vue event system
vm.$broadcast('event-name', args)
and
vm.$on('event-name', function())
Here is the fiddle:
http://jsfiddle.net/hfalucas/wc1gg5v4/59/
A slightly different (simpler) version of the accepted answer:
Have a component registered on the parent instance:
export default {
components: { 'my-component': myComponent }
}
Render the component in template/html with a reference:
<my-component ref="foo"></my-component>
Access the component method:
<script>
this.$refs.foo.doSomething();
</script>
Say you have a child_method() in the child component:
export default {
methods: {
child_method () {
console.log('I got clicked')
}
}
}
Now you want to execute the child_method from parent component:
<template>
<div>
<button #click="exec">Execute child component</button>
<child-cmp ref="child"></child_cmp> <!-- note the ref="child" here -->
</div>
</template>
export default {
methods: {
exec () { //accessing the child component instance through $refs
this.$refs.child.child_method() //execute the method belongs to the child component
}
}
}
If you want to execute a parent component method from child component:
this.$parent.name_of_method()
NOTE: It is not recommended to access the child and parent component like this.
Instead as best practice use Props & Events for parent-child communication.
If you want communication between components surely use vuex or event bus
Please read this very helpful article
This is a simple way to access a component's methods from other component
// This is external shared (reusable) component, so you can call its methods from other components
export default {
name: 'SharedBase',
methods: {
fetchLocalData: function(module, page){
// .....fetches some data
return { jsonData }
}
}
}
// This is your component where you can call SharedBased component's method(s)
import SharedBase from '[your path to component]';
var sections = [];
export default {
name: 'History',
created: function(){
this.sections = SharedBase.methods['fetchLocalData']('intro', 'history');
}
}
Using Vue 3:
const app = createApp({})
// register an options object
app.component('my-component', {
/* ... */
})
....
// retrieve a registered component
const MyComponent = app.component('my-component')
MyComponent.methods.greet();
https://v3.vuejs.org/api/application-api.html#component
Here is a simple one
this.$children[indexOfComponent].childsMethodName();
I am not sure is it the right way but this one works for me.
First import the component which contains the method you want to call in your component
import myComponent from './MyComponent'
and then call any method of MyCompenent
myComponent.methods.doSomething()
Declare your function in a component like this:
export default {
mounted () {
this.$root.$on('component1', () => {
// do your logic here :D
});
}
};
and call it from any page like this:
this.$root.$emit("component1");
If you're using Vue 3 with <script setup> sugar, note that internal bindings of a component are closed (not visible from outside the component) and you must use defineExpose(see docs) to make them visible from outside. Something like this:
<script setup lang="ts">
const method1 = () => { ... };
const method2 = () => { ... };
defineExpose({
method1,
method2,
});
</script>
Since
Components using are closed by default
Sometimes you want to keep these things contained within your component. Depending on DOM state (the elements you're listening on must exist in DOM when your Vue component is instantiated), you can listen to events on elements outside of your component from within your Vue component. Let's say there is an element outside of your component, and when the user clicks it, you want your component to respond.
In html you have:
Launch the component
...
<my-component></my-component>
In your Vue component:
methods() {
doSomething() {
// do something
}
},
created() {
document.getElementById('outsideLink').addEventListener('click', evt =>
{
this.doSomething();
});
}
I have used a very simple solution. I have included a HTML element, that calls the method, in my Vue Component that I select, using Vanilla JS, and I trigger click!
In the Vue Component, I have included something like the following:
<span data-id="btnReload" #click="fetchTaskList()"><i class="fa fa-refresh"></i></span>
That I use using Vanilla JS:
const btnReload = document.querySelector('[data-id="btnReload"]');
btnReload.click();

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