VueJS 2 - How to Pass Parameters Using $emit - javascript

I am working on a modal component using VueJS 2. Right now, it basically works -- I click on a button and the modal opens, etc.
What I want to do now is create a unique name for the modal and associate the button with that particular button.
This is what I have in mind. The modal has a unique name property:
<modal name='myName'>CONTENT</modal>
And this would be the associate button:
<button #click="showModal('myName')"></button>
What I need to figure out is how to pass the parameter of showModal to the modal component.
Here is the method that I'm using in the root vue instance (i.e, NOT inside my modal component):
methods: {
showModal(name) { this.bus.$emit('showModal'); },
}
What I want to do is to access the name property in the component -- something like this:
created() {
this.bus.$on('showModal', () => alert(this.name));
}
But this shows up as undefined.
So what am I doing wrong? How can I access the name property inside the modal component?
NOTE: If you are wondering what this.bus.$on is, please see the following answer to a previous question that I asked: https://stackoverflow.com/a/42983494/7477670

Pass it as a parameter to $emit.
methods: {
showModal(name) { this.bus.$emit('showModal', name); },
}
created() {
this.bus.$on('showModal', (name) => alert(name));
}
Also, if you want to give the modal a name, you need to accept it as a prop in the modal component.
Vue.component("modal",{
props:["name"],
...
})
Then I assume you will want to do something like,
if (name == this.name)
//show the modal

<!-- File name is dataTable.vue -->
<template>
<div>
<insertForm v-on:emitForm="close"></insertForm>
</div>
</template>
<script>
import InsertForm from "./insertForm";
import Axios from "axios";
export default {
components: {
InsertForm
},
data: () => ({
}),
methods: {
close(res) {
console.log('res = ', res);
}
}
};
</script>
<!-- File name is insertForm.vue -->
<template>
<div>
<v-btn #click.native="sendPrameter">
<v-icon>save</v-icon>
</v-btn>
</div>
</template>
<script>
export default {
data: () => ({
mesage:{
msg:"Saved successfully",
color:'red',
status:1
}
}),
methods: {
sendPrameter: function() {
this.$emit("emitForm", this.mesage);
}
}
};
</script>
https://vuejs.org/v2/guide/components-custom-events.html

Related

Access scoped slot from component

I got this component:
<template>
<Popover v-slot="{ open }">
<PopoverButton>
{{ title }}
</PopoverButton>
<div v-if="computedOpen">
<PopoverPanel static>
<slot name="popover"></slot>
</PopoverPanel>
</div>
</Popover>
</template>
<script>
import {Popover, PopoverButton, PopoverPanel} from '#headlessui/vue'
import {computed, ref, watch} from 'vue'
import {useRoute} from 'vue-router'
export default {
name: 'DropdownMenuButton',
mixins: [slots],
props: {
name: {
type: String,
},
title: {
type: String,
default: ''
},
},
components: {
Popover,
PopoverButton,
PopoverPanel,
ChevronDownIcon,
},
setup(props) {
const isOpen = ref(null);
const route = useRoute()
watch(route, () => {
isOpen.value = false;
});
const computedOpen = computed(() => {
let open = ...? //this is missing...
return isOpen.value && open.value;
});
return {
computedOpen
}
},
}
</script>
This component makes use of headless UI's popover.
Now I'd like to close the popover once the route changes. While the route-change is being detected fine, I can not access the <Popover>'s open value in the setup() method to determine, whether computedOpen should return true or false.
My question: How can I access v-slot="{ open } in the computed value?
What you want is not possible.
Think about it:
Everything inside <Popover> element (the slot content) is compiled by Vue to a function returning the virtual DOM representation of the content
This function is passed to the Popover component as slots.default and when the Popover component is rendering, it calls that function passing the open value as an argument
So open value is Popover component's internal state and is only accessible inside the template (ie. slot render function)
So I think your best bet is throw away the computed idea and just use the open value directly in the template or use method instead, passing open as an argument
<div v-if="isOpen && open">
<PopoverPanel static>
<slot name="popover"></slot>
</PopoverPanel>
</div>
<div v-if="isPanelOpen(open)">
<PopoverPanel static>
<slot name="popover"></slot>
</PopoverPanel>
</div>

how to move items to another component by click - vue.js

I was wondering how can I move my items -> book, from one component to another. I took this books from api and I show them in the list, so I have an ID.
<template>
<v-flex v-for="(book, index) in allBooks">
<div>Title: {{ book.title }}</div>
<i #click="markAsFavorite(book)" :class="{isActive: isMark}" class="fas fa-heart"></i>
</template>
//component books
<script>
name: 'Books',
data () {
return {
allBooks: [],
isMark: false,
favouriteBooks: []
}
},
mounted() {
axios.get("https://www.googleapis.com/books/v1/volumes?q=id:" + this.id)
.then(response => {
console.log(response)
this.allBooks = response.data.items.map(item => ({...item, isMark: false}))
console.log(this.allBooks)
})
.catch(error => {
console.log(error)
})
},
methods: {
markAsFavorite(book) {
this.isMark = !this.isMark
let favouriteAllBooks = this.favouriteBooks.push(book => {
book.id = // i dont know what?
})
},
}
</script>
//component favourite
<template>
<div class=showFavouriteBook>
<p></p>
</div>
</template>
I tried to compare this marked book ID to something, and then this array with marked books show in second template favourite. But I have no idea how to do this. Maybe somebody can prompt me something?
You should use a global eventBus for that. An 'eventBus' is another instance of Vue which is used to pass data via components tied to the main application.
At the root script of your application append the following:
const eventBus = new Vue({
data: function() {
return {
some_var: null,
}
}
});
You can use Vue mixin to have your event bus accessible globally easily:
Vue.mixin({
data: function() {
return {
eventBus: eventBus,
}
}
});
Now when you want to pass data between components you can use the bus:
Component 1
// for the sake of demo I'll use mounted method, which is invoked each time component is mounted
<script>
export default {
mounted: function() {
this.eventBus.some_var = 'it works!'
}
}
</script>
Component 2
<template>
<div>
{{ eventBus.some_var }} <!-- it works -->
</div>
</template>
In addition you can use $emit and $on.
Component 1
// for the sake of demo I'll use mounted method, which is invoked each time component is mounted
<script>
export default {
mounted: function() {
// emit 'emittedVarValue' event with parameter 'it works'
this.eventBus.$emit('emittedVarValue', 'it works!')
}
}
</script>
Component 2
<template>
<div>
{{ some_var }} <!-- "it works" once eventBus receives event "emittedVarValue" -->
</div>
</template>
<script>
export default {
data: function() {
return {
some_var: null
}
},
mounted: function() {
// waiting for "emittedVarValue" event
this.eventBus.$on('emittedVarValue', (data)=>{
this.some_var = data;
})
}
}
</script>
Hope this answer helps you.

Vue.js Loading and hiding async component

I am making a chatbot in vue.js and I need your help. I created 2 Vue components:
ChatLoader.vue - first components that render a button to open actual webchat window
Webchat.vue - the async component that only loads when I
Click on a button to open the chat window.
So what my ChatLoader.vue is doing is setting parameter chatInitialized = true on button click. Then the chat window is opened.
In my Webchat.vue I have a close button which on click only hides the chat window (not removed from DOM) by setting showWindow = false;
Now when the chat window is hidden I again see the button to open the chat (which was there all the time only not visible because overlapped by chatwindow) but when I click on the button now I want to set showWindow = true in Webchat.vue component instead of the previous behavior, so the webchat window is shown again.
ChatLoading.vue:
<template>
<div>
<span class="open-chat" v-on:click="showChat">
<i class="icon ficon-live-chat"></i>
Virtual assistant
</span>
<Webchat v-if="chatInitialized"></Webchat>
</div>
</template>
<script>
import ChatLoading from "./ChatLoading.vue";
const Webchat = () => ({
component: import('./Webchat.vue'),
loading: ChatLoading
});
export default {
data() {
return {
chatInitialized: false
}
},
components: {
Webchat
},
methods: {
showChat() {
this.chatInitialized = true;
}
}
}
</script>
Webchat.vue:
<template>
<div class="chat-window" v-show="showWindow">
<button type="button" class="cancel icon ficon-close" v-on:click="minimize"></button>
<WebchatPlugin
>
</<WebchatPlugin>
</div>
</template>
<script>
import <WebchatPlugin{
createDirectLine,
createStore
} from "botframework-webchat/lib/index";
import {DirectLine} from "botframework-directlinejs";
export default {
data() {
return {
showWindow : true
}
},
components: <WebchatPlugin
methods: {
minimize() {
this.showWindow = false
}
},
</script>
How can I accomplish that? Thank you
If you want to toggle the child component's (<Webchat>) state showWindow from a consuming parent component, then you will have to create a method in the child component that can be invoked by the parent element.
First of all, in your Webchat component, create a new method, say maximize, that will change this.showWindow to true:
methods: {
minimize() {
this.showWindow = false;
},
maximize() {
this.showWindow = true;
}
},
Then, in your parent component, you can then:
Create a reference to your Webchat component
Use this.$ref to access the component and its inner methods, and call the maximize() method you've just created:
Example:
<template>
<div>
<span class="open-chat" v-on:click="showChat">
<i class="icon ficon-live-chat"></i>
Virtual assistant
</span>
<!-- Use `ref` attribute to create a reference to component -->
<Webchat ref="webchat" v-if="chatInitialized"></Webchat>
</div>
</template>
<script>
import ChatLoading from "./ChatLoading.vue";
const Webchat = () => ({
component: import('./Webchat.vue'),
loading: ChatLoading
});
export default {
data() {
return {
chatInitialized: false
}
},
components: {
Webchat
},
methods: {
showChat() {
this.chatInitialized = true;
// Access Webchat component's inner method
// Do this inside `this.$nextTick` to ensure it is accessible
this.$nextTick(() => {
this.$refs.webchat.maximize();
});
}
}
}
</script>

Building a form with Vuejs. Pass data from children to parent

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.

vuejs passing array of checkboxes to parent template is only passing one value

I looked at potential dupes of this, such as this one and it doesn't necessarily solve my issue.
My scenario is that I have a component of orgs with label and checkbox attached to a v-model. That component will be used in combination of other form components. Currently, it works - but it only passes back one value to the parent even when both checkboxes are click.
Form page:
<template>
<section>
<h1>Hello</h1>
<list-orgs v-model="selectedOrgs"></list-orgs>
<button type="submit" v-on:click="submit">Submit</button>
</section>
</template>
<script>
// eslint-disable-next-line
import Database from '#/database.js'
import ListOrgs from '#/components/controls/list-orgs'
export default {
name: 'CreateDb',
data: function () {
return {
selectedOrgs: []
}
},
components: {
'list-orgs': ListOrgs,
},
methods: {
submit: function () {
console.log(this.$data)
}
}
}
</script>
Select Orgs Component
<template>
<ul>
<li v-for="org in orgs" :key="org.id">
<input type="checkbox" :value="org.id" name="selectedOrgs[]" v-on:input="$emit('input', $event.target.value)" />
{{org.name}}
</li>
</ul>
</template>
<script>
import {db} from '#/database'
export default {
name: 'ListOrgs',
data: () => {
return {
orgs: []
}
},
methods: {
populateOrgs: async function (vueObj) {
await db.orgs.toCollection().toArray(function (orgs) {
orgs.forEach(org => {
vueObj.$data.orgs.push(org)
})
})
}
},
mounted () {
this.populateOrgs(this)
}
}
</script>
Currently there are two fake orgs in the database with an ID of 1 and 2. Upon clicking both checkboxes and clicking the submit button, the selectedOrgs array only contains 2 as though the second click actually over-wrote the first. I have verified this by only checking one box and hitting submit and the value of 1 or 2 is passed. It seems that the array method works at the component level but not on the component to parent level.
Any help is appreciated.
UPDATE
Thanks to the comment from puelo I switched my orgListing component to emit the array that is attached to the v-model like so:
export default {
name: 'ListOrgs',
data: () => {
return {
orgs: [],
selectedOrgs: []
}
},
methods: {
populateOrgs: async function (vueObj) {
await db.orgs.toCollection().toArray(function (orgs) {
orgs.forEach(org => {
vueObj.$data.orgs.push(org)
})
})
},
updateOrgs: function () {
this.$emit('updateOrgs', this.$data.selectedOrgs)
}
},
mounted () {
this.populateOrgs(this)
}
}
Then on the other end I am merely console.log() the return. This "works" but has one downside, it seems that the $emit is being fired before the value of selectedOrgs has been updated so it's always one "check" behind. Effectively,I want the emit to wait until the $data object has been updated, is this possible?
Thank you so much to #puelo for the help, it helped clarify some things but didn't necessarily solve my problem. As what I wanted was the simplicity of v-model on the checkboxes populating an array and then to pass that up to the parent all while keeping encapsulation.
So, I made a small change:
Select Orgs Component
<template>
<ul>
<li v-for="org in orgs" :key="org.id">
<input type="checkbox" :value="org.id" v-model="selectedOrgs" name="selectedOrgs[]" v-on:change="updateOrgs" />
{{org.name}}
</li>
</ul>
</template>
<script>
import {db} from '#/database'
export default {
name: 'ListOrgs',
data: () => {
return {
orgs: []
}
},
methods: {
populateOrgs: async function (vueObj) {
await db.orgs.toCollection().toArray(function (orgs) {
orgs.forEach(org => {
vueObj.$data.orgs.push(org)
})
})
},
updateOrgs: function () {
this.$emit('updateOrgs', this.$data.selectedOrgs)
}
},
mounted () {
this.populateOrgs(this)
}
}
</script>
Form Page
<template>
<section>
<h1>Hello</h1>
<list-orgs v-model="selectedOrgs" v-on:updateOrgs="updateSelectedOrgs"></list-orgs>
<button type="submit" v-on:click="submit">Submit</button>
</section>
</template>
<script>
// eslint-disable-next-line
import Database from '#/database.js'
import ListOrgs from '#/components/controls/list-orgs'
export default {
name: 'CreateDb',
data: function () {
return {
selectedOrgs: []
}
},
components: {
'list-orgs': ListOrgs
},
methods: {
updateSelectedOrgs: function (org) {
console.log(org)
},
submit: function () {
console.log(this.$data)
}
}
}
</script>
What the primary change here is I now fire a method of updateOrgs when the checkbox is clicked and I pass the entire selectedOrgs array via the this.$emit('updateOrgs', this.$data.selectedOrgs)`
This takes advantage of v-model maintaining the array of whether they're checked or not. Then on the forms page I simply listen for this event on the component using v-on:updateOrgs="updateSelectedOrgs" which contains the populated array and maintains encapsulation.
The documentation for v-model in form binding still applies to custom components, as in:
v-model is essentially syntax sugar for updating data on user input
events...
https://v2.vuejs.org/v2/guide/forms.html#Basic-Usage and
https://v2.vuejs.org/v2/guide/components-custom-events.html#Customizing-Component-v-model
So in your code
<list-orgs v-model="selectedOrgs"></list-orgs>
gets translated to:
<list-orgs :value="selectedOrgs" #input="selectedOrgs = $event.target.value"></list-orgs>
This means that each emit inside v-on:input="$emit('input', $event.target.value) is actually overwriting the array with only a single value: the state of the checkbox.
EDIT to address the comment:
Maybe don't use v-model at all and only listen to one event like #orgSelectionChange="onOrgSelectionChanged".
Then you can emit an object with the state of the checkbox and the id of the org (to prevent duplicates):
v-on:input="$emit('orgSelectionChanged', {id: org.id, state: $event.target.value})"
And finally the method on the other end check for duplicates:
onOrgSelectionChanged: function (orgState) {
const index = selectedOrgs.findIndex((org) => { return org.id === orgState.id })
if (index >= 0) selectedOrgs.splice(index, 1, orgState)
else selectedOrgs.push(orgState)
}
This is very basic and not tested, but should give you an idea of how to maybe solve this.

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