I am new to vue and I am having problems passing props from one component to another and I need help
events.js
<div class="location__time-details">
<h3 class="location__subheader">{{ event.venue }}</h3>
<CartManagement :event="event"/>
</div>
</div>
I am trying to get the properties from event
Cart.js
props: ["id", "event"],
defined the props
data: function() {
return {
regular: null,
event:"",
};
},
Passed it
<h1 class="modal__text">{{ event.name}}</h1>
But the error shows Duplicate key, what am I doing wrong and what is the solution?
You cannot have both data and props with the same name. Remove event from your data. And you can give a default value of your props as follow.
props : {
...
event : {
type : 'Object',
default : function(){
return {
name : ''
// and other fields
};
}
}
}
Related
I am building an MVP and this is the first time I do web development. I am using Vue2 and Firebase and so far, things go well.
However, I ran into a problem I cannot solve alone. I have an idea how it SHOULD work but cannot write it into code and hope you guys can help untangle my mind. By now I am incredibly confused and increasingly frustrated :D
So lets see what I got:
Child Component
I have built a child component which is a form with three text-areas. To keep it simple, only one is included it my code snippets.
<template>
<div class="wrap">
<form class="form">
<p class="label">Headline</p>
<textarea rows="2"
v-model="propHeadline"
:readonly="readonly">
</textarea>
// To switch between read and edit
<button
v-if="readonly"
#click.prevent="togglemode()">
edit
</button>
<button
v-else
type="submit"
#click.prevent="togglemode(), updatePost()"
>
save
</button>
</form>
</div>
</template>
<script>
export default {
name: 'PostComponent'
data() {
return {
readonly: true
}
},
props: {
propHeadline: {
type: String,
required: true
}
},
methods: {
togglemode() {
if (this.readonly) {
this.readonly = false
} else {
this.readonly = true
}
},
updatePost() {
// updates it to the API - that works
}
}
}
</script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
And my parent component:
<template>
<div class="wrap">
<PostComponent
v-for="post in posts"
:key="post.id"
:knugHeadline="post.headline"
/>
</div>
</template>
<script>
import PostComponent from '#/components/PostComponent.vue'
export default {
components: { PostComponent },
data() {
return {
posts: []
}
},
created() {
// Gets all posts from DB and pushes them in array "posts"
}
</script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
Current Status
So far, everything works. I can display all posts and when clicking on "edit" I can make changes and save them. Everything gets updated to Firebase - great!
Problem / Error Message
I get the following error message:
[Vue warn]: Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or computed property based on the prop's value.
As the error says I should use a computed property based on the props value. But how can I achieve that?
Solution Approach
I believe I have to use a computed getter to return the prop value - how to do that?
And then I have to use the setter to emit an event to the parent to update the value so the prop passes it back down - how to do that?
I have found bits and pieces online but by now all I see is happy families passing around small packages of data...
Would be really thankful for a suggestion on how to solve this one! :)
Thanks a lot!
This error shows because of your v-model on texterea which mutate the prop, but in vue it is illegal to mutate props :
<textarea rows="2"
v-model="propHeadline"
:readonly="readonly">
</textarea>
So, what you could do is to use this created() lifecycle hook and set the propHeadline prop as data :
<script>
export default {
name: 'PostComponent'
data() {
return {
readonly: true,
headline: ""
}
},
props: {
propHeadline: {
type: String,
required: true
}
},
created() {
this.headline = this.propHeadline
}
}
</script>
An then, update the new variable on your textarea :
<textarea rows="2"
v-model="headline"
:readonly="readonly">
</textarea>
I am trying to build a component that creates filter buttons and then sends the type attribute in the filters object through the event bus to be handled elsewhere in my app. However, when I added the array of objects (filters) in the data section, I am getting an error of this.filter is not defined when I click on a button.
I would like to keep the filters array in this component because I am also trying to dynamically change the active class to whichever button has been clicked.
Am I missing something that has to do with props? Why am I unable to display the buttons when the data and v-for was on another component? These were the questions I have been asking myself in order of solving this issue.
<template>
<div>
<button
v-for="(filter, index) in filters"
:key="index"
:class="{ active: index === activeItem }"
#click="emitFilter(), selectItem(index)"
:filter="filter"
>
{{ filter.name }}
</button>
</div>
</template>
<script>
import EventBus from '#/components/EventBus'
export default {
props: {
filter: { type: String }
},
data() {
return {
activeItem: 0,
filterResult: '',
filters: [
{ name: 'All', type: 'all' },
{ name: 'Holidays', type: 'holiday' },
{ name: 'Seasons', type: 'season' },
{ name: 'Events', type: 'custom' }
]
}
},
methods: {
emitFilter() {
this.filterResult = this.filter
EventBus.$emit('filter-catagories', this.filterResult)
},
selectItem(index) {
this.activeItem = index
}
}
}
</script>
My button component is used in a filters component
<template>
<div>
<span>filters</span>
<FilterBtn />
</div>
</div>
</template>
<script>
import FilterBtn from '#/components/FilterBtn'
export default {
components: {
FilterBtn
}
// data() {
// return {
// filters: [
// { name: 'All', type: 'all' },
// { name: 'Holidays', type: 'holiday' },
// { name: 'Seasons', type: 'season' },
// { name: 'Events', type: 'custom' }
// ]
// }
// }
}
</script>
As you can see, the commented section is where I had my filters originally, but I had to move them to the button component in order to add the active class.
I'm assuming you were actually trying to access the filter iterator of v-for="(filter, index) in filters" from within emitFilter(). For this to work, you'd need to pass the filter itself in your #click binding:
<button v-for="(filter, index) in filters"
#click="emitFilter(filter)">
Then, your handler could use the argument directly:
export default {
methods: {
emitFilter(filter) {
this.filterResult = filter
//...
}
}
}
You are passing a prop called filter typed string to your component. When you output {{ filter.name }} you are actually referring to this property instead of the variable filter you create within the v-for loop.
Unless you passed a property called "filter" to your component, this property will be undefined. Therefore outputting filter.name will result in this error message.
Yea you dont pass an prop to your component thats why its undefined.
<FilterBtn filter="test" />
Here i pass an prop named filter with the value of test.
Sure you could pass dynamic props. Just bind it.
<FilterBtn :filter="yourData" />
I need to ask: Are you passing an object or an string?
Because you defined your prop to be a string, but you actually use it as an object
{{ filter.name }}
Maybe you should also set the type to Object.
props: {
filter: { type: Object }
},
I'm trying to build a form using "v-for" for input component and then generate a pdf file with PDFMake using data from inputs. But I didn't know how to pass the data from input component back to parent.
I read a lot of topics, but can't find a way to do this.
Here is short code without additional inputs, checkboxes etc. I plan to use around 15 inputs with different parameters to generate final PDF. Some of parameters also will be used to change final data depending of conditional statements.
Everything is work fine if code in one file, without loop and components. But not now.
Here is parent:
<template lang="pug">
.form
Input(v-for="data in form.client_info" v-bind:key="data.id" v-bind:data="data")
button(#click="pdfgen") Download PDF
</template>
<script>
export default {
components: {
Input: () => import('#/components/items/form/input')
},
data() {
return {
client_name: '',
client_email: '',
form: {
client_info: [
{id:'client_name', title:'Name'},
{id:'client_email', title: 'Email'},
{id:'foo', title: 'foo'}
],
}
}
},
methods: {
pdfgen: function () {
var pdfMake = require('pdfmake/build/pdfmake.js')
if (pdfMake.vfs == undefined) {
var pdfFonts = require('pdfmake/build/vfs_fonts.js')
pdfMake.vfs = pdfFonts.pdfMake.vfs;
}
if (this.foo) {
var foo = [
'Foo: ' + this.foo
];
} else {
foo = ''
]
}
var docDefinition = {
content: [
'Name: ' + this.client_name,
'Email: ' + this.client_email,
'\n',
foo
]
}
pdfMake.createPdf(docDefinition).download('Demo.pdf');
}
}
}
</script>
Here is a children (Input component):
<template lang="pug">
label.form_item
span.form_item_title {{ data.title }}
input.form_item_input(:v-model="data.id" type="text")
</template>
<script>
export default {
props: ['data']
}
</script>
Any ideas how to make it work?
You'll want to use a method that vue has build-in named $emit().
Before going into how to do that, a quick explanation. Because vue attempts to make data flow one-directional there is not a super quick way to just pass data back to a parent. What Vue proposes instead is to pass a method to the child component that, when called, will 'emit' the value it changed to it's parent and the parent can then do what it wants with that value.
So, in your parent component you'll want to add a method that will handle a change when the child emits. This could look something like:
onChildValueChanged(value){ this.someValue = value }
The value we passed to the function will be coming from our child component. We will need to define in our child component what this function should do. In your child component you could have a function that looks like so:
emitValueChange(event){ this.$emit('childFunctionCall', this.someChildValue) }
Next we need to tie those two functions together by adding an attribute on our child template. In this example that might look like:
<Child :parentData="someData" v-on:childFunctionCall="onChildValueChanged"></Child>
What that above template is doing is saying that when the function on:childFunctionCall is 'emited' then our function in the parent scope should fire.
Finally, in the child template we just need to add some event that calls out emiter. That could look like:
<button v-on:click="emitToParent">This is a button</button>
So when our button is clicked, the emiter is called. This triggers the function in our child component named 'emitToParent' which in turn calls the function we passed to our child component.
You'll have to tailor your use case to match the exam
I found a solution using Vuex.
So now my components look like this.
Here is parent:
<template lang="pug">
.form
Input(v-for="data in formClient" v-bind:key="data.id" v-bind:data="data")
button(#click="pdfgen") Download PDF
</template>
<script>
export default {
components: {
Input: () => import('#/components/items/form/input'),
store: () => import('#/store'),
},
computed: {
formClient() { return this.$store.getters.client }
}
}
</script>
Here is a children (Input component):
<template lang="pug">
label.form_item
span.form_item_title {{ data.title }}
input.form_item_input(v-model="data.value" :type="data.input_type")
</template>
<script>
export default {
props: ['data'],
computed: {
form: {
get () {
return this.$store.state.obj.message
},
set (value) {
this.$store.commit('updateMessage', value)
}
}
}
}
</script>
Here is a store module:
<script>
export default {
actions: {},
mutations: {},
state: {
form: {
client: [
{id:'client_name', title:'Name', value: ''},
{id:'client_email', title: 'Email', value: ''},
{id:'foo', title: 'foo', value: ''}
]
}
},
getters: {
client: state => {
return state.form.client;
}
}
}
</script>
Now I can read updated data from store directly from PDFMake function.
I have made a global component that will render the content we want.
This component is very simple
<template>
<section
id="help"
class="collapse"
>
<div class="container-fluid">
<slot />
</div>
</section>
</template>
<script>
export default {
name: 'VHelp',
};
</script>
I use it inside my base template with
<v-help />
I'm trying to add content to this component slot from another single file component using.
<v-help>
<p>esgssthsrthsrt</p>
</v-help>
But this logically create another instance of my comp, with the p tag inside. Not the correct thing I want to do.
So I tried with virtual DOM and rendering function, replacing slot by <v-elements-generator :elements="$store.state.help.helpElements" /> inside my VHelp comp.
The store helpElements is a simple array with objects inside.
{
type: 'a',
config: {
class: 'btn btn-default',
},
nestedElements: [
{
type: 'span',
value: 'example',
},
{
type: 'i',
},
],
},
Then inside my VElementsGenerator comp I have a render function that with render element inside virtual DOM from an object like
<script>
import {
cloneDeep,
isEmpty,
} from 'lodash';
export default {
name: 'VElementsGenerator',
props: {
elements: {
type: Array,
required: true,
},
},
methods: {
iterateThroughObject(object, createElement, isNestedElement = false) {
const generatedElement = [];
for (const entry of object) {
const nestedElements = [];
let elementConfig = {};
if (typeof entry.config !== 'undefined') {
elementConfig = cloneDeep(entry.config);
}
if (entry.nestedElements) {
nestedElements.push(this.iterateThroughObject(entry.nestedElements, createElement, true));
}
generatedElement.push(createElement(
entry.type,
isEmpty(elementConfig) ? entry.value : elementConfig,
nestedElements
));
if (typeof entry.parentValue !== 'undefined') {
generatedElement.push(entry.parentValue);
}
}
if (isNestedElement) {
return generatedElement.length === 1 ? generatedElement[0] : generatedElement;
}
return createElement('div', generatedElement);
},
},
render(createElement) {
if (this.elements) {
return this.iterateThroughObject(this.elements, createElement);
}
return false;
},
};
</script>
This second method is working well but if I want to render complex data, the object used inside the rendering function is very very long and complex to read.
So I'm trying to find another way to add content to a global component used inside a base layout only when I want it on a child component.
I can't use this VHelp component directly inside children comps because the HTML page architecture will be totally wrong.
I'm wondering if this is possible to add content (preferably HTML) to a component slot from a single file comp without re-creating a new instance of the component?
Furthermore I think this is very ugly to save HTML as string inside a Vuex store. So I don't even know if this is possible and if I need to completely change the way I'm trying to do this.
Any ideas ?
In the store, you should only store data and not an HTML structure. The way to go with this problem would be to store the current state of the content of the v-help component in the store. Then, you would have a single v-help component with a slot (like you already proposed). You should pass different contents according to the state in the store. Here is an abstract example:
<v-help>
<content-one v-if="$store.state.content === 'CONTENT_ONE' />
<content-two v-else-if="$store.state.content === 'CONTENT_TWO' />
<content-fallback v-else />
</v-help>
Child element somewhere else:
<div>
<button #click="$store.commit('setContentToOne')">Content 1</button>
</div>
Vuex Store:
state: {
content: null
},
mutations: {
setContentToOne(state) {
state.content = 'CONTENT_ONE';
}
}
Of course it depends on your requirements and especially on how many different scenarios are used if this is the best way to achieve this. If I understood you correctly, you are saving help elements to the store. You could also save an array of currently selected help elements in there and just display them directly in the v-help component.
EDIT:
Of course you can also just save the static component (or its name) in the store. Then, you could dynamically decide in the child components, which content is shown in v-help. Here is an example:
<v-help>
<component :is="$store.state.helpComponent" v-if="$store.state.helpComponent !== null" />
</v-help>
Test Component:
<template>
test component
</template>
<script>
export default {
name: 'test-component'
};
</script>
Child element somewhere else (variant 1, storing the name in Vuex):
<div>
<button #click="$store.commit('setHelpComponent', 'test-component')">Set v-help component to 'test-component'</button>
</div>
Child element somewhere else (variant 2, storing the whole component in Vuex):
<template>
<button #click="$store.commit('setHelpComponent', testComponent)">Set v-help component to testComponent (imported)</button>
</template>
<script>
import TestComponent from '#/components/TestComponent';
export default {
name: 'some-child-component',
computed: {
testComponent() {
return TestComponent;
}
}
};
</script>
Child element somewhere else (variant 3, storing the name, derived from the imported component, in Vuex; I would go with this variant):
<template>
<button #click="$store.commit('setHelpComponent', testComponentName)">Set v-help component to 'test-component'</button>
</template>
<script>
import TestComponent from '#/components/TestComponent';
export default {
name: 'some-child-component',
computed: {
testComponentName() {
return TestComponent.name;
}
}
};
</script>
Vuex Store:
state: {
helpComponent: null
},
mutations: {
setHelpComponent(state, value) {
state.helpComponent = value;
}
}
See also the documentation for dynamic components (<component :is=""> syntax): https://v2.vuejs.org/v2/guide/components.html#Dynamic-Components
I've a dynamic view:
<div id="myview">
<div :is="currentComponent"></div>
</div>
with an associated Vue instance:
new Vue ({
data: function () {
return {
currentComponent: 'myComponent',
}
},
}).$mount('#myview');
This allows me to change my component dynamically.
In my case, I have three different components: myComponent, myComponent1, and myComponent2. And I switch between them like this:
Vue.component('myComponent', {
template: "<button #click=\"$parent.currentComponent = 'myComponent1'\"></button>"
}
Now, I'd like to pass props to myComponent1.
How can I pass these props when I change the component type to myComponent1?
To pass props dynamically, you can add the v-bind directive to your dynamic component and pass an object containing your prop names and values:
So your dynamic component would look like this:
<component :is="currentComponent" v-bind="currentProperties"></component>
And in your Vue instance, currentProperties can change based on the current component:
data: function () {
return {
currentComponent: 'myComponent',
}
},
computed: {
currentProperties: function() {
if (this.currentComponent === 'myComponent') {
return { foo: 'bar' }
}
}
}
So now, when the currentComponent is myComponent, it will have a foo property equal to 'bar'. And when it isn't, no properties will be passed.
You can also do without computed property and inline the object.
<div v-bind="{ id: someProp, 'other-attr': otherProp }"></div>
Shown in the docs on V-Bind - https://v2.vuejs.org/v2/api/#v-bind
You could build it like...
comp: { component: 'ComponentName', props: { square: true, outlined: true, dense: true }, model: 'form.bar' }
<component :is="comp.component" v-bind="{...comp.props}" v-model="comp.model"/>
I have the same challenge, fixed by the following:
<component :is="currentComponent" v-bind="resetProps">
{{ title }}
</component>
and the script is
export default {
…
props:['title'],
data() {
return {
currentComponent: 'component-name',
}
},
computed: {
resetProps() {
return { ...this.$attrs };
},
}
<div
:color="'error'"
:onClick="handleOnclick"
:title="'Title'"
/>
I'm came from reactjs and I found this solve my issue
If you have imported you code through require
var patientDetailsEdit = require('../patient-profile/patient-profile-personal-details-edit')
and initalize the data instance as below
data: function () {
return {
currentView: patientDetailsEdit,
}
you can also reference the component through the name property if you r component has it assigned
currentProperties: function() {
if (this.currentView.name === 'Personal-Details-Edit') {
return { mode: 'create' }
}
}
When you use the <component> inside a v-for you can change the answer of thanksd as follow:
methods: {
getCurrentProperties(component) {
if (component === 'myComponent') {
return {foo: baz};
}
}
},
usage
<div v-for="object in object.items" :key="object._your_id">
<component :is="object.component" v-bind="getCurrentProperties(object.component)" />
</div>
Let me know if there is an easier way.