I'm learning how to use vue.js
I've a shared hosting plan where I can only use html. I'm fetching the data I need using axios and a remote wordpress installation that will act as a backend only. What I need to know, is how I can change the DOM content of the index.html using vue if the user click on a link and I need to change the layout of the page because a different presentation for the contents is needed?
See the example:
<div id="vue-app">
link to layout 2
<div class="col-12">starting layout </div>
</div>
// after the user click the link (v-on:click) the layout change
<div id="vue-app">
link to layout 1
// layout change
<div class="col-6">new layout </div>
<div class="col-6">new layout </div>
</div>
Please read up on Conditional Rendering in Vue.js.
You can have a boolean variable in the data compartment of your script tag and change it on click.
And in the tags put v-if="your_bool_variable".
<div id="vue-app" v-if="layout_switch">
link to layout 2
<div class="col-12">starting layout </div>
</div>
// after the user click the link (v-on:click) the layout change
<div id="vue-app" v-else>
link to layout 1
// layout change
<div class="col-6">new layout </div>
<div class="col-6">new layout </div>
</div>
Negate the boolean variable at the #click event.
Data could look like the following:
<script>
export default {
name: "YourComponent",
data: () => {
return {
layout_switch: true
}
},
methods: {
changeLayout() {
this.layout_switch = !this.layout_switch;
}
}
}
</script>
<div class="flex">
<div class="layout-row layout-align-end-center">
{{#paper-button href="overview" raised=true primary=true}}Overview{{/paper-button}}
{{#paper-button href="incomes"}}Incomes{{/paper-button}}
{{#paper-button href="expenses"}}Expenses{{/paper-button}}
{{#paper-button href="settings"}}Settings{{/paper-button}}
</div>
</div>
So I am trying to set the raised=true whenever I am on certain page/template. The above code is from my application template. Is there any way of doing this using JS/Ember or should I just do it manually in each of my templates?
I think the best way to go is to write a custom component wrapping paper-button. ember-route-helpers gives you nice helpers to do that:
{{#paper-button
onclick={{transition-to #route)
href=(url-for #route)
raised=(is-active #route)
primary=(is-active #route)
}}
{{yield}}
{{/paper-button}}
Then you can use that component with {{#your-component route="settings"}}Settings{{/your-component}}.
It's important to understand that you should pass both the action and the href. Because then when people click on the button it will make a transition and dont reload the entire page, but rightlick->open and screenreaders are are not broken.
I am creating a program for my Universities Research department, the program is for the operation of an Atomic Layer Deposition system.
The program needs to be able to allow the user to set a custom 'recipe' if you will, each grid-item will have a button with 'edit' in the bottom corner, and will take you to a separate page where you can enter your system stats like zone temps, durations, cycles, etc. We have gotten the draggable grid-items working, so that we could make the system run multiple steps over and over if we wish, but here is my goal I can't seem to accomplish:
We need to be able to add a new 'step' grid-item on button click, and we need to be able to remove a grid-item as well. I have created a button 'New Tile' and I defined a function I was hoping would work, I was trying to see if I could duplicate a grid item, but when I run the program and click the button I get the error:
"[Vue warn]: Property or method "duplicate" 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."
Image of app: https://imgur.com/a/DgKebPR
image of JS trying to be used: https://imgur.com/a/EjW4t6d
<h2 style="color: #f6a821;">Steps</h2>
<hr class="hr" />
<grid-layout
:layout.sync="stepsGrid"
:col-num="8"
:row-height="75"
:is-draggable="true"
:is-resizable="false"
:is-mirrored="false"
:vertical-compact="true"
:margin="[50, 50]"
:use-css-transforms="true">
<div id="duplicater">
<grid-item
:x=stepsGrid[0].x
:y=stepsGrid[0].y
:w=stepsGrid[0].w
:h=stepsGrid[0].h
:i=stepsGrid[0].i
:isDraggable=stepsGrid[0].isDraggable>
<div class="Panel__name">1</div>
<div class="editButton">
<router-link to="/Parameters-template" class="editButton">Edit</router-link></router-link>
</div><br>
<div class="Panel__status">Status:</div>
</grid-item>
<div id="bottombuttons">
<button id="resetbutton">Reset</button>
<button id="startbutton" #click="duplicate()">New Tile</button>
</div>
</div>
I don't get where is declared the duplicate method extactly. Don't expect it to be available from a template if it's not declared in the component's methods. Try:
methods: {
duplicate() {
/* */
}
}
in the same component. If it needs to be a shared among several components, put this in a mixin.
I don't know what the error is, so far I am testing through console log to check for changes after selecting a file (for uploading).
When I run $ npm run watch, i get the following error:
"Webpack is watching the files…
95% emitting
ERROR Failed to compile with 1 errors
19:42:29
error in ./resources/assets/js/components/File.vue
(Emitted value instead of an instance of Error) Vue template syntax
error:
Component template should contain exactly one root element. If you
are using v-if on multiple elements, use v-else-if to chain them
instead.
# ./resources/assets/js/components/AvatarUpload.vue 5:2-181 #
./resources/assets/js/app.js # multi ./resources/assets/js/app.js
./resources/assets/sass/app.scss"
My File.vue is
<template>
<div class="form-group">
<label for="avatar" class="control-label">Avatar</label>
<input type="file" v-on:change="fileChange" id="avatar">
<div class="help-block">
Help block here updated 4 🍸 ...
</div>
</div>
<div class="col-md-6">
<input type="hidden" name="avatar_id">
<img class="avatar" title="Current avatar">
</div>
</template>
<script>
export default{
methods: {
fileChange(){
console.log('Test of file input change')
}
}
}
</script>
Any ideas on how to solve this? What is actually the error?
Note This answer only applies to version 2.x of Vue. Version 3 has lifted this restriction.
You have two root elements in your template.
<div class="form-group">
...
</div>
<div class="col-md-6">
...
</div>
And you need one.
<div>
<div class="form-group">
...
</div>
<div class="col-md-6">
...
</div>
</div>
Essentially in Vue you must have only one root element in your templates.
For a more complete answer: http://www.compulsivecoders.com/tech/vuejs-component-template-should-contain-exactly-one-root-element/
But basically:
Currently, a VueJS template can contain only one root element (because of rendering issue)
In cases you really need to have two root elements because HTML structure does not allow you to create a wrapping parent element, you can use vue-fragment.
To install it:
npm install vue-fragment
To use it:
import Fragment from 'vue-fragment';
Vue.use(Fragment.Plugin);
// or
import { Plugin } from 'vue-fragment';
Vue.use(Plugin);
Then, in your component:
<template>
<fragment>
<tr class="hola">
...
</tr>
<tr class="hello">
...
</tr>
</fragment>
</template>
You need to wrap all the html into one single element.
<template>
<div>
<div class="form-group">
<label for="avatar" class="control-label">Avatar</label>
<input type="file" v-on:change="fileChange" id="avatar">
<div class="help-block">
Help block here updated 4 🍸 ...
</div>
</div>
<div class="col-md-6">
<input type="hidden" name="avatar_id">
<img class="avatar" title="Current avatar">
</div>
</div>
</template>
<script>
export default{
methods: {
fileChange(){
console.log('Test of file input change')
}
}
}
</script>
if, for any reasons, you don't want to add a wrapper (in my first case it was for <tr/> components), you can use a functionnal component.
Instead of having a single components/MyCompo.vue you will have few files in a components/MyCompo folder :
components/MyCompo/index.js
components/MyCompo/File.vue
components/MyCompo/Avatar.vue
With this structure, the way you call your component won't change.
components/MyCompo/index.js file content :
import File from './File';
import Avatar from './Avatar';
const commonSort=(a,b)=>b-a;
export default {
functional: true,
name: 'MyCompo',
props: [ 'someProp', 'plopProp' ],
render(createElement, context) {
return [
createElement( File, { props: Object.assign({light: true, sort: commonSort},context.props) } ),
createElement( Avatar, { props: Object.assign({light: false, sort: commonSort},context.props) } )
];
}
};
And if you have some function or data used in both templates, passed them as properties and that's it !
I let you imagine building list of components and so much features with this pattern.
Component template should contain exactly one root element. If you are using v-if on multiple elements, use v-else-if to chain them instead.
The right approach is
<template>
<div> <!-- The root -->
<p></p>
<p></p>
</div>
</template>
The wrong approach
<template> <!-- No root Element -->
<p></p>
<p></p>
</template>
Multi Root Components
The way around to that problem is using functional components, they are components where you have to pass no reactive data means component will not be watching for any data changes as well as not updating it self when something in parent component changes.
As this is a work around it comes with a price, functional components don't have any life cycle hooks passed to it, they are instance less as well you cannot refer to this anymore and everything is passed with context.
Here is how you can create a simple functional component.
Vue.component('my-component', {
// you must set functional as true
functional: true,
// Props are optional
props: {
// ...
},
// To compensate for the lack of an instance,
// we are now provided a 2nd context argument.
render: function (createElement, context) {
// ...
}
})
Now that we have covered functional components in some detail lets cover how to create multi root components, for that I am gonna present you with a generic example.
<template>
<ul>
<NavBarRoutes :routes="persistentNavRoutes"/>
<NavBarRoutes v-if="loggedIn" :routes="loggedInNavRoutes" />
<NavBarRoutes v-else :routes="loggedOutNavRoutes" />
</ul>
</template>
Now if we take a look at NavBarRoutes template
<template>
<li
v-for="route in routes"
:key="route.name"
>
<router-link :to="route">
{{ route.title }}
</router-link>
</li>
</template>
We cant do some thing like this we will be violating single root component restriction
Solution
Make this component functional and use render
{
functional: true,
render(h, { props }) {
return props.routes.map(route =>
<li key={route.name}>
<router-link to={route}>
{route.title}
</router-link>
</li>
)
}
Here you have it you have created a multi root component, Happy coding
Reference for more details visit: https://blog.carbonteq.com/vuejs-create-multi-root-components/
In addition to Bert and blobmaster responses:
If you need to remove the root element from the DOM you can exploit css and use display: value on the root element.
Bit of a misleading error.
What fixed it on my side was the fact that I had an additional </div> without an opening <div>.
I spotted it using Find/Replace on "div" which gave an odd number.
Wrap everything in one div and it will resolve the issue.
For example,
div
----div
----/div>
----div>
----/div>
/div
It is similar concept to React.js
For vue 3 they removed this constraint in template syntax :
<template>
<header>...</header>
<main v-bind="$attrs">...</main>
<footer>...</footer>
</template>
but it's still existing in JSX syntax :
Incorrect ❌
setup(props,{attrs}) {
return ()=>(
<header>...</header>
<main {..attrs}>...</main>
<footer>...</footer>
)
}
Correct ✔
setup(props,{attrs}) {
return ()=>(
<>
<header>...</header>
<main {..attrs}>...</main>
<footer>...</footer>
</>
)
}
I experienced this kind of issue and the issue was fixed by adding a main parent div tag or section if it is a section type of component.
<div class="list-of-friends">
<h3>Hello World</h3>
</div>
I was confused as I knew VueJS should only contain 1 root element and yet I was still getting this same "template syntax error Component template should contain exactly one root element..." error on an extremely simple component. Turns out I had just mispelled </template> as </tempate> and that was giving me this same error in a few files I copied and pasted. In summary, check your syntax for any mispellings in your component.
instead of using this
Vue.component('tabs', {
template: `
<div class="tabs">
<ul>
<li class="is-active"><a>Pictures</a></li>
<li><a>Music</a></li>
<li><a>Videos</a></li>
<li><a>Documents</a></li>
</ul>
</div>
<div class="tabs-content">
<slot></slot>
</div>
`,
});
you should use
Vue.component('tabs', {
template: `
<div>
<div class="tabs">
<ul>
<li class="is-active"><a>Pictures</a></li>
<li><a>Music</a></li>
<li><a>Videos</a></li>
<li><a>Documents</a></li>
</ul>
</div>
<div class="tabs-content">
<slot></slot>
</div>
</div>
`,
});
Just make sure that you have one root div and put everything inside this root
<div class="root">
<!--and put all child here --!>
<div class='child1'></div>
<div class='child2'></div>
</div>
and so on
I have some content I wish to load into a div using Angular. For example:
<div class="number-and-description" ng-controller="thingDetails">
<div class="number" ng-click="loadContent(thing.number, thing.description, thing.status)" ng-cloak>{{ thing.number }}</div>
<p class="description" ng-click="loadContent(thing.number, thing.description, thing.status)" ng-cloak>{{ thing.description }}</p>
</div>
I have another view outside of this div like this:
<!-- Main Content Area -->
<section class="main-content group" ng-controller="thingDetails">
<h1 ng-cloak>{{ thingNumber }}</h1>
<div ng-cloak>{{ thingDescription }}</div>
<div ng-cloak>{{ thingStatus }}</div>
</section>
In my app.js file, I have this code:
thingApp.controller('thingDetails', ["$scope", function($scope) {
$scope.loadContent = function(number, description, status) {
$scope.thingNumber = number;
$scope.thingDescription = description;
$scope.thingStatus = status;
return $scope;
};
}]);
My question is, why doesn't the main content area div update when these values are changed? Right now it remains blank. thing.number, thing.description loads fine in the div I am clicking on - this data is coming from hardcoded JSON which appears fine. The issue is that when I click on the div, the OTHER main content div doesn't show/update the data. Could someone please help me out? Note that when I console.log(number) or console.log(description) etc. I can see the correct values, so they are being passed correctly to the loadContent() function.
You have two separate instances of controller thingDetails , not one. They each have their own scope and do not share anything directly. A simple way to see this is put a console.log() in your controller and you will see it run each time the controller initializes
For controllers to share data you use a service and inject that service wherever it needs to be accessed.
Alternatively perhaps you don't need two instances and can wrap them in one scope in your view
You are basically creating two controllers here with two different scopes. Thus, in the outer div, $scope.thingNumber, description, etc. are undefined as you are only changing the values on the inner scope.
A quick but messy fix to this problem would be to change your $scope's to $rootScopes. The proper way to do this though is via services/factories.