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how to v-model on different array vue 3

Hi I was trying to use a v-model an input to a value in object in an array of object in Vue 3. The complexity lies in the fact the object is first processed by a function. And that it need to be processed every time when a change is made to an input. Here is my code (and a sandbox link) :
<template>
<div id="app">
<div v-for="param in process(parameters)" :key="param">
Name : {{param.name}} Value : <input v-model="param.value">
</div>
{{parameters}}
</div>
</template>
<script>
export default {
name: "App",
data(){
return{
parameters :[
{'name':'Richard Stallman','value':'cool dude'},
{'name':'Linus Torvalds','value':'very cool dude'},
{'name':'Dennis Ritchie','value':'very very cool dude'}
]
}
},
methods:{
process(parameters){
const results = parameters.map( param =>{
return {name:param.name+' extra text',
value:param.value+' extra text',
}
})
return results
}
}
};
</script>
I just want the original parameters to change when something is types in the inputs. Maybe #change could be of use. But I didn't find a fix with #change. Does anyone know a solution to my problem? Thanks in advance.

Use computed property to get reactive state of the data.
Working Demo :
new Vue({
el: '#app',
data: {
parameters :[
{'name':'Richard Stallman','value':'cool dude'},
{'name':'Linus Torvalds','value':'very cool dude'},
{'name':'Dennis Ritchie','value':'very very cool dude'}
]
},
computed: {
process() {
const results = this.parameters.map((param) => {
return {
name: param.name + ' extra text',
value: param.value + ' extra text'
}
});
return results;
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<div v-for="param in process" :key="param">
Name : {{param.name}}
Value : <input v-model="param.value">
</div><br>
<strong>Orinigal Data :</strong> {{parameters}}
</div>

I am not entirely sure I understood whether the person should be able to see/edit the text you added within you processing method.
Anyway, I think this sample of code should solve you problem :
<template>
<div id="app">
<div v-for="param in parameters" :key="param.name">
Name : {{ param.name }} Value : <input v-model="param.value" />
</div>
{{ process }}
</div>
</template>
<script>
export default {
name: "App",
data() {
return {
parameters: [
{ name: "Richard Stallman", value: "cool dude" },
{ name: "Linus Torvalds", value: "very cool dude" },
{ name: "Dennis Ritchie", value: "very very cool dude" },
],
};
},
computed: {
process: function() {
const results = this.parameters.map((param) => {
return {
name: param.name + " extra text",
value: param.value + " extra text",
};
});
return results;
},
},
};
</script>
So, we're iterating through the parameters array directly, adding an input on the value just like you did.
When you type in the input, you update the parameter linked to it, in live.
I just switched the method you made into a computed method.
This way, every time parameters is updated, "process" is also updated because it's depending on it directly.
I also removed passing the "parameters" argument, it's in the component data, you can just access it directly.
This way, using "process" just like any variable, you'll always have the updated parameters + what you added to em.

Why if I get the object property within the computed object gets undefined but not the object itself? Which approach fits better in this context?

My Greeting.
To put in context, my purpose of asking this question is to be able to render a child component inside a form based on the selected option of the <app-selector> Vue component as simple and silly as that.
For the sake of simplicity. I've made a snippet down here to expose what I'm trying to figure out.
Basically, the aim is to get the component name to be rendered by using the computed property cardTypeComponent. However, I want to fathom the way cardTypeComponent is working, since I cannot see why, in one hand, the first return (return this.form) is giving the object (this.form) with the property I want (card_type) but on the other hand the second return (return this.form.card_type ? this.form.card_type + 'Compose' : '') is giving me an empty string, assuming this.form.card_type is undefined when it is clear looking at the first return that, in fact, is not taking it as undefined.
There is way more context, since once the option is selected there is a validation process from the server before setting the value inside this.form object. Moreover, the form interaction is through steps, so once the user select the option he has to click a button to reach the form fields that corresponds to that type card selected, therefore the component is not going to be rendered the very first moment the user selects an option as in the snippet approach. However, it would entangle what I'm asking. Thanks beforehand.
It is better to use the Fiddle link below.
Snippet
var appSelector = Vue.component('app-selector', {
name: 'AppSelector',
template: `<div>
<label for="card_type">Card Type:</label>
<select :name="name" value="" #change="sendSelectedValue">
<option v-for="option in options" :value="option.value">
{{ option.name }}
</option>
</select>
</div>`,
props: {
name: {
required: false,
type: String,
},
options: {
required: false,
type: Array,
}
},
methods: {
sendSelectedValue: function(ev) {
this.$emit('selected', ev.target.value, this.name)
}
}
});
var guessByImageCompose = Vue.component({
name: 'GuessByImageComponse',
template: `<p>Guess By Image Compose Form</p>`
});
var guessByQuoteCompose = Vue.component({
name: 'GuessByQuoteComponse',
template: `<p>Guess By Quote Compose Form</p>`
});
new Vue({
el: '#app',
components: {
appSelector: appSelector,
guessByImageCompose: guessByImageCompose,
guessByQuoteCompose: guessByQuoteCompose,
},
data() {
return {
form: {},
card_types: [
{
name: 'Guess By Quote',
value: 'GuessByQuote'
},
{
name: 'Guess By Image',
value: 'GuessByImage'
}
],
}
},
computed: {
cardTypeComponent: function() {
return this.form; // return { card_type: "GuessByImage" || "GuessByQuote" }
return this.form.card_type ? this.form.card_type + 'Compose' : ''; // return empty string ("") Why?
}
},
methods: {
setCardType: function(selectedValue, field) {
this.form[field] = selectedValue;
console.log(this.form.card_type); // GuessByImage || GuessByQuote
console.log(this.cardTypeComponent); // empty string ("") Why?
}
},
mounted() {
console.log(this.cardTypeComponent); // empty string ("")
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<form action="#" method="post">
<app-selector
:name="'card_type'"
:options="card_types"
#selected="setCardType"
>
</app-selector>
{{ cardTypeComponent }} <!-- Always empty string !-->
<component v-if="cardTypeComponent !== ''" :is="cardTypeComponent">
</component>
</form>
</div>
https://jsfiddle.net/k7gnouty/2/

You're setting a property on this.form which is not initialized first in data. This means you have run into Vue's change detection caveat. Use Vue.set when setting it:
methods: {
setCardType: function(selectedValue, field) {
Vue.set(this.form, field, selectedValue);
}
}
Alternatively, you could declare the properties first if that works better for you.

VueJS 2.0 v-model dynamic target inside v-for

I've got a form with about 10 select elements built from an array in my Vue data.
The array of selectors is empty initially and then an AJAX call populates the array and Vue builds the HTML - I've kept the snippet below simplified just to demonstrate the issue I'm having with v-model
I want to create an object that has all the selected values in it, so I'm trying to use v-model="selected[ selector.name ]" as per the example below.
I want to easily be able to ask for selected.make or selected.fuel
Now this works if I initialize the selected property like this:
selected: { make: 'audi', fuel: 'petrol' }
If I leave it blank, like in the example, {}, then it doesn't get updated.
I don't want to manually hardcode all the properties of selected, I only want to be listing them once in the server side code that gets sent via AJAX
So am I missing something completely obvious, should I be doing this in a different way?
Maybe a method to find the dropdown that matches a field name and returns the value? Just that doesn't seem like a very Vue thing to do.
var app = new Vue({
el: '#example',
data: {
selectors: [
{
name: 'make',
options: ['audi','bmw']
},
{
name: 'fuel',
options: ['petrol','diesel']
}
],
selected: {}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.3/vue.js"></script>
<div id="example">
<template v-for="selector in selectors">
<select v-model="selected[ selector.name ]">
<option v-for="option in selector.options">{{option}}</option>
</select>
</template>
<p>
{{selected.make}}
<br />
{{selected.fuel}}
</p>
</div>

it's probably becuase you're not setting new keys on an object with this.$set
try:
this.$set(this.selected, 'make', 'audi')
Not using this.$set - alias of Vue.set - will mean Vue doesn't set the new key as reactive, and in turn won't be watching for any updates to it, docs: https://v2.vuejs.org/v2/api/#vm-set
var app = new Vue({
el: '#example',
data: {
selectors: [{
name: 'make',
options: ['audi', 'bmw']
}, {
name: 'fuel',
options: ['petrol', 'diesel']
}],
selected: null,
},
created () {
// this would happen following your ajax request - but as an example this should suffice
this.selected = {}
this.selectors
.forEach((selector) => {
this.$set(this.selected, selector.name, '')
})
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.3/vue.js"></script>
<div id="example">
<div v-if="selected">
<select v-model="selected[selector.name]" v-for="selector in selectors">
<option :value="option" v-for="option in selector.options">
{{option}}
</option>
</select>
<p>make: {{selected.make}}<p>
<p>fuel: {{selected.fuel}}</p>
<pre>{{ selected }}</pre>
</div>
</div>

How to get an input field value in Vue

I'm new to Vue and I would like some help getting a value from an input field:
In my form I have:
<input type="hidden" id="groupId" value="1">
If I was using jQuery I would do:
var group_id = $('#groupId').val();
However, in Vue I don't know how to bind the hidden field:
<div id="app">
<input type="text" v-model="groupId"> //Where do I put the value?
</div>
new Vue({
el: '#app',
data: {
groupId: //What do I put here to get the field's value?
}
How can I achieve this?

Update to the update: See this answer. Previously updated answer was wrong.
Original answer:
In Vue, you don't get things from the view and put things into the view. Vue does that. You do all manipulations in the viewmodel, and make bindings in the view so that Vue knows how to synchronize it. So you'd bind the input to your model data item:
<input type="hidden" id="groupId" v-model="groupId">
and set its value in your viewmodel:
data: {
groupId: 1
}

I had the same question. I'm working with Vue + Laravel.
For me, the solution was simple after searching and not finding a concrete solution in the Vue documentation.
Simply:
document.getElementById('MyId').value;
Details in → https://www.w3schools.com/jsref/prop_text_value.asp
It is not the most efficient solution, but it works for now!
Greetings.

Working sample of getting value from input field in this case it is hidden type:
<input type="hidden" name="test">
<script>
new Vue ({
created () {
const field = document.querySelector("input[name=test]").value
console.log(field)
}
})
</script>

this code helped me
i hope that this work with you
define the input
<div class="root">
<input type="hidden" ref="groupId" value="1">
<button type="button" v-on:click="get_id()">test</button>
</div>
define the method
new Vue({
el: ".root",
data: {
id: null,
}
methods: {
get_id() {
this.id = this.$refs.groupId.value;
}
}
});

// if you want it displayed on your page, use {{ groupId }}
/* you can get the value by using #change.enter=".." #keypress.enter="getInputValue",
or #input="getInputValue" or #click="getInputValue" using button,
or if it is with a form element, #submit.prevent="getInputValue" */
/* #keypress.enter tracks input but only calls the function when the Enter key
is pressed, #input track changes as it's being entered */
// it is important to use event.preventDefault() when using #change or #keypress
<div id="app">
<input type="text" v-model="groupId">
<p> {{ groupId }} </p>
<button #click="getInputValue">Get Input</button>
</div>
new Vue({
el: '#app',
data: {
groupId: //What do I put here to get the field's value?
// for what to put there, you can use an empty string or null
groupId: "",
},
// to get the value from input field
methods: {
getInputValue: function() {
if(this.groupId !== "") {
console.log(this.groupId);
}
},
}
})

look at this I did it in laravel, vuejs, vuetable2 and children's row, and don't use the v-model:
this.$refs['est_'+id_det].localValue
en VUE:
<div class="col-md-3">
<b-form-select class="form-control selectpicker" :ref="'est_'+props.row.id_detalle_oc"
:value="props.row.id_est_ven" v-on:change="save_estado(props.row.id_detalle_oc)">
<option value="0">Sin estado</option>
<option value="1">Pendiente</option>
<option value="2">Impresa</option>
<option value="3">Lista</option>
</b-form-select>
in methods
methods: {
save_estado:function (id_det){
var url= 'ordenes-compra/guardar_est_ven'
var id_estado = this.$refs['est_'+id_det].localValue
axios.post(url,{
id_det: id_det,
id_est_ven: id_estado,
est_ven: est_ve
}).then(function (response) {
var respuesta= response.data;
if(respuesta == "OK"){
swal({
type: 'success',
title: '¡Éxito!',
text: 'Estado modificado',
confirmButtonText: 'Entendido',
})
}
})
.catch(function (error) {
console.log(error);
});
},
I hope it helps, I've been hanging around for a while.
Regards

Hi you can also try the following:
const input = this.$el.firstElementChild;
in case you are using TypeScript, declare input as:
: HTMLInputElement
Then, you can simply get the value if you do:
input.value
Hope it helps!

Ok, this does the job: document.querySelector('#groupId').getAttribute('value');

Ember bindings firing when not wanted, and not firing when required

Hey I'm having two different issues in my ember app, both of which involve bindings.
First, I have a binding firing when I don't want it to. Basically what I'm trying to achieve (I'm building a survey creator front-end app) is that when any text is entered into the 'name' field of a question, I want to add a new question object, which will render out another blank question at the end of the list of questions that the user is adding. This has the effect of there always being a new question, so an add question button is not required. The binding is working, and a new object is being added: however, since the binding is from the newest question object, the binding is triggered again when the new object is created, which in turn creates a new object, which triggers the binding again....which obviously eventually crashes the browser. I've tried using the Ember._suspendObserver function, but there isn't a lot of documentation on this, and I think I'm using it wrong - anyhow it isn't suspending the observer or pausing the binding. The observer in the code is around line 27 (contentsNameObserver)
The other issue I'm having -- I have a selection drop down box which selects what type of question the user wants (single answer, multi-choice, etc.) but the binding between the select box and the {{#each}} helper which renders the kind of question isn't triggering. I'm using the Ember.Select view helper, so there shouldn't be any issues with using get/set to fire the binding. I'm using a computed property to return an array of fields for the question type based on the value of the question type id. The computed property is in line 13 (App.SurveyContent.types), and the template templates/step3. Quick heads up that this app may be extended for more than surveys, hence 'questions' are often referred to in the code as 'content'.
I'm pretty new to ember (this is my first real app) so my code most likely has a lot of issues outside of these problems...so any comments on how I've structured my app would be hugely appreciated as well!
Javascript ember app:
App = Ember.Application.create({
rootElement: '#emberContainer'
});
App.SurveyContent = Ember.Object.extend({
name: "",
content_type: 1,
content_pos: 1,
hash: Em.A([]),
types: function() {
alert("redraw");
return App.ContentTypes[this.content_type-1].hash;
}.property()
});
App.Surveys = Ember.Object.create({
name: null,
start: $.datepicker.formatDate('mm/dd/yy' , new Date()),
end: $.datepicker.formatDate('mm/dd/yy' , new Date()),
themeID: 0,
contents: [App.SurveyContent.create()], //Pushing an instance of App.SurveyContent onto this
contentsNameObserver: function() {
context = this;
console.log("entering");
Em._suspendObserver(App.Surveys, "contents.lastObject.name", false, false, function() {
console.log("suspend handler");
context.contents.pushObject(App.SurveyContent.create());
})
}.observes("contents.lastObject.name")
});
App.ContentTypes = [
Ember.Object.create({name: 'Text question', id:1, hash: [Ember.Object.create({name: 'Question', help: 'Enter the question here', type: 'text'})]}),
Ember.Object.create({name: 'Multichoice question', id:2, hash: [Ember.Object.create({name: 'Question', help: 'Enter the question here', type: 'text'}),
Ember.Object.create({name: 'Answer', help: 'Enter possible answers here', type: 'text', multiple: true})]})
];
App.ViewTypeConvention = Ember.Mixin.create({
viewType: function() {
console.log(this);
return Em.get("Ember.TextField");
}.property().cacheable()
});
App.CRMData = Ember.Object.extend();
App.CRMData.reopenClass ({
crm_data: [],
org_data: [],
org_display_data: [],
loadData: function() {
context = this;
context.crm_data = [];
$.getJSON ("ajax/crm_data", function(data) {
data.forEach(function(crm) {
context.crm_data.pushObject(App.CRMData.create({id: crm.crm_id, name: crm.crm_name}));
crm.orgs.forEach(function(org) {
context.org_data.pushObject(App.CRMData.create({id: org.org_id, name: org.org_name, crm_id: crm.crm_id}));
}, context)
}, context)
context.updateOrganisations(5);
});
return this.crm_data;
},
updateOrganisations: function(crm_id) {
context = this;
this.org_display_data.clear();
console.log("clearing the buffer")
console.log(this.org_display_data)
context.org_data.forEach(function(org) {
if(org.crm_id == crm_id) {
context.org_display_data.pushObject(App.CRMData.create({id: org.id, name: org.name}));
}
}, context)
}
});
App.DateField = Ember.TextField.extend({
attributeBindings: ['id', 'class']
});
App.CRMSelect = Ember.Select.extend({
attributeBindings: ['id'],
change: function(evt) {
console.log(evt)
App.CRMData.updateOrganisations($('#crm').val())
}
});
App.ApplicationController = Ember.Controller.extend();
App.Step1Controller = Ember.ArrayController.extend({});
App.Step2Controller = Ember.ArrayController.extend({});
App.Step2Controller = Ember.ArrayController.extend({});
App.ApplicationView = Ember.View.extend({
templateName: 'app'
});
App.Step0View = Ember.View.extend ({
templateName: 'templates/step0'
});
App.Step1View = Ember.View.extend ({
templateName: 'templates/step1'
});
App.Step2View = Ember.View.extend ({
templateName: 'templates/step2',
didInsertElement: function() {
$( ".jquery-ui-datepicker" ).datepicker();
}
});
App.Step3View = Ember.View.extend ({
templateName: 'templates/step3',
});
App.Router = Em.Router.extend ({
enableLogging: true,
root: Em.Route.extend ({
showstep1: Ember.Route.transitionTo('step1'),
showstep2: Ember.Route.transitionTo('step2'),
showstep3: Ember.Route.transitionTo('step3'),
index: Ember.Route.extend({
route: '/',
connectOutlets: function(router){
router.get('applicationController').connectOutlet( 'step0');
}
}),
step1: Ember.Route.extend ({
route: 'step1',
connectOutlets: function(router){
router.get('applicationController').connectOutlet( 'step1', App.CRMData.loadData());
}
}),
step2: Ember.Route.extend ({
route: 'step2',
connectOutlets: function(router) {
router.get('applicationController').connectOutlet('step2')
},
}),
step3: Ember.Route.extend ({
route: 'step3',
connectOutlets: function(router) {
router.get('applicationController').connectOutlet('step3')
},
})
})
});
Ember.LOG_BINDINGS=true;
App.LOG_BINDINGS = true;
App.ContentTypes.forEach(function(object) {
object.hash.forEach(function(hash) {
hash.reopen(App.ViewTypeConvention);
}, this);
}, this);
Html templates (I've got these in haml, so this is just a representation of the important ones)
<script type="text/x-handlebars" data-template-name="app">
{{outlet}}
</script>
<script type="text/x-handlebars" data-template-name="templates/step3">
<h1> Add content to {{App.Surveys.name}} </h1>
<br>
<div id = "accordion2" class = "accordion">
{{#each content in App.Surveys.contents}}
<div class="accordion-group">
<div class = "accordion-heading">
<a class = "accordion-toggle" data-parent = "#accordion2" data-toggle = "collapse" href = "#collapseOne">
{{content.name}}
</a>
</div>
<div id = "collapseOne" class = "accordion-body collapse in">
{{view Ember.TextField valueBinding="content.name" class="txtName"}}
<form class = "form-horizontal">
<div class = "accordion-inner">
<div class = "control-group">
<label class = "control-label" for ="organisation">
Content Type
<div class = "controls">
{{view Ember.Select contentBinding="App.ContentTypes" optionValuePath="content.id" optionLabelPath="content.name" valueBinding="content.content_type"}}
</div>
</div>
</div>
{{#each item in content.types }}
<div class = "control-group" >
<label class = "control-label" for = "organisation">
{{item.name}}
<div class = "controls">
{{view item.viewType }}
</div>
{{/each}}
</div>
</form>
</div>
{{/each}}
</div>
</div>
<br>
<div class = "btn" {:_action => 'showstep3'}> Next Step > </div>
</script>

I've solved the first issue, although I didn't get the suspendObserver property working I used an if statement to check the previous element, removing the infinite loop.
contentsNameObserver: function() {
context = this;
if(this.get('contents.lastObject').name) {
context.contents.pushObject(App.SurveyContent.create());
}
}.observes("contents.lastObject.name")
Any comments on how to get the _suspendObserver handler working would be appreciated though, it is something that should work but I'm doing something wrong
I've created a stripped down jsfiddle at http://jsfiddle.net/reubenposthuma/sHPv4/
It is set up to go straight to the problem step, step 3, so that I don't need to include all the previous templates.
I'm still stuck on the issue of the binding not firing though. The behaviour I'm expecting is that when the 'Content Type' dropdown box is changed, the text box underneath should change, it should re-render with two text boxes.

I realise this is an old question, but there is no documenation and precious little information I could find searching either, hence sharing what I found worked here.
What I found worked was to call Ember._suspendObserver as follows:
somePropertyDidChange: function(key) {
var that = this;
Ember._suspendObserver(this, key, null,
'somePropertyDidChange', function() {
// do stuff which would normally cause feedback loops
that.set('some.property', 'immune to feedback');
});
}.observes('some.property');
You can also use the multiple observer variant as follows:
somePropertiesDidChange: function(key) {
var that = this;
Ember._suspendObservers(this, ['some.property', 'another.property'],
null, 'somePropertiesDidChange', function() {
// do stuff which would normally cause feedback loops
that.set('some.property', 'immune to feedback');
that.set('another.property', 'also immune to feedback');
});
}.observes('some.property', 'another.property');
In my exact use case I actually called Ember._suspendObservers from an Ember.run.once() function which was setup by the observer since I wanted to make sure a number of dependant properties had settled before doing calculations which in turn would mutate some of those properties.