Vue2: handling multi-child prop synchronization with models - javascript

I'm new to Vue (about a, and while reading the docs is very helpful it is often the case where I can not derive how I am supposed to achieve the desired behavior.
I have made several small components to get the feel for passing props and handling events, so now I am trying to makes something a bit larger but am facing some difficulty.
This difficulty stems from the following:
I would like to have a custom select component that are initialized via a v-for loop. All the while I would like to have access to these components selected option. I can bind the select data with v-model in the select component, but I am struggling to get that information out to the wrapper, yet alone the container looping over the wrappers.
Note: I am using Rollup and single file components
top-level
<template >
<div>
<select-container
v-for="(select, index) in selects"
:index="index"
:key="select.id"
:select.sync="select"
/>
</div>
</template>
<script>
import selectContainer from './select-container.vue';
export default {
components: { selectContainer },
props: {
records: {
default: function(){return{}},
type: Object
}
},
data: function() {
return {
selects: [{}, {}]
}
},
computed: {
},
methods: {
}
}
</script>
<style scoped>
</style>
select-container
<template>
<div>
<my-select
v-model.sync="select"
/>
</div>
</template>
<script>
import mySelect from './my-select.vue';
export default {
components: { mySelect },
props: {
index: { type: Number },
select: {
type: Object,
default: function(){return{}}
}
},
data : function(){
return {
}
},
methods: {
},
computed: {
}
}
</script>
<style scoped>
</style>
my-select
<template>
<select v-model="selected">
<option
v-for="(attr, index) in attributes"
:value="attr"
:selected="attr == selected"
>
{{attr}}
</option>
</select>
</template>
<script>
export default {
props: {
attributes: {
type: Array,
default: function() {
return []
}
}
},
data: function() {
return {
selected: ""
}
}
}
</script>
<style scoped>
</style>

There's still a lot of code in the post that I'm not following, but I think the gist of your question is how to reflect the selected property from the <my-select> component through to the <select-container> component. If that's the case, then the most straightforward approach is probably just to add a value and emit input events.
In the template, add an event handler for the native <select>
<select v-model="selected" #input="onInput">
Then, in the code, reflect that event up to the parent. Also be sure to accept a value property from that parent.
export default {
props: {
value: null,
},
data: function() {
return {
selected: this.value
}
},
methods: {
onInput() {
this.$emit("input", this.selected)
}
},
watch: {
value(newValue) {
this.selected = newValue;
}
}
}
And then the parent can simply use the conventional v-model binding.
<my-select v-model="select"/>

Related

Vue not reacting to a computed props change

I am using the Vue composition API in one of my components and am having some trouble getting a component to show the correct rendered value from a computed prop change. It seems that if I feed the prop directly into the components render it reacts as it should but when I pass it through a computed property it does not.
I am not sure why this is as I would have expected it to be reactive in the computed property too?
Here is my code:
App.vue
<template>
<div id="app">
<Tester :testNumber="testNumber" />
</div>
</template>
<script>
import Tester from "./components/Tester";
export default {
name: "App",
components: {
Tester,
},
data() {
return {
testNumber: 1,
};
},
mounted() {
setTimeout(() => {
this.testNumber = 2;
}, 2000);
},
};
</script>
Tester.vue
<template>
<div>
<p>Here is the number straight from the props: {{ testNumber }}</p>
<p>
Here is the number when it goes through computed (does not update):
{{ testNumberComputed }}
</p>
</div>
</template>
<script>
import { computed } from "#vue/composition-api";
export default {
props: {
testNumber: {
type: Number,
required: true,
},
},
setup({ testNumber }) {
return {
testNumberComputed: computed(() => {
return testNumber;
}),
};
},
};
</script>
Here is a working codesandbox:
https://codesandbox.io/s/vue-composition-api-example-forked-l4xpo?file=/src/components/Tester.vue
I know I could use a watcher but I would like to avoid that if I can as it's cleaner the current way I have it
Don't destruct the prop in order to keep its reactivity setup({ testNumber }) :
setup(props) {
return {
testNumberComputed: computed(() => {
return props.testNumber;
}),
};
}

Make a reactive component with vuejs

I need a Vue component to show some HTML content in v-data-table from Vuetify. I have seen this post Vue 2 contentEditable with v-model, and I created a similar code shown below.
My problem is the component is not reactive. When I click the "Test button", no content is updated in HtmlTextArea.
<template>
<div>
<v-btn #click="doTest()">Test Button</v-btn>
<HtmlTextArea
v-model="content"
style="max-height:50px;overflow-y: scroll;"
></HtmlTextArea>
</div>
<template>
export default {
name: "ModelosAtestados",
components: { HtmlTextArea },
data: () => ({
content: "",
}),
methods: {
doTest() {
this.content = "kjsadlkjkasfdkjdsjkl";
},
},
};
//component
<template>
<div ref="editable" contenteditable="false" v-on="listeners"></div>
</template>
<script>
export default {
name: "HtmlTextArea",
props: {
value: {
type: String,
default: "",
},
},
computed: {
listeners() {
return { ...this.$listeners, input: this.onInput };
},
},
mounted() {
this.$refs.editable.innerHTML = this.value;
},
methods: {
onInput(e) {
this.$emit("input", e.target.innerHTML);
},
},
};
</script>
This occurs because HtmlTextArea sets the div contents to its value prop only in the mounted lifecycle hook, which is not reactive.
The fix is to setup a watcher on value, so that the div contents are updated to match whenever a change occurs:
// HtmlTextArea.vue
export default {
watch: {
value: {
handler(value) {
this.$refs.editable.innerHTML = value;
}
}
}
}
demo
In the #click event binder, you have to pass a function. You passed the result of an executed function.
To make it work: #click="doTest" or #click="() => doTest()".
How to debug such problems:
Display the value you want to update on your template to check if its updated: {{content}}
Use the vue devtool extension to check the current state of your components

Why not my vue component not re-rendering?

I have a question why not this component, not re-rendering after changing value so what I'm trying to do is a dynamic filter like amazon using the only checkboxes so let's see
I have 4 components [ App.vue, test-filter.vue, filtersInputs.vue, checkboxs.vue]
Here is code sandbox for my example please check the console you will see the value changing https://codesandbox.io/s/thirsty-varahamihira-nhgex?file=/src/test-filter/index.vue
the first component is App.vue;
<template>
<div id="app">
<h1>Filter</h1>
{{ test }}
<test-filter :filters="filters" :value="test"></test-filter>
</div>
</template>
<script>
import testFilter from "./test-filter";
import filters from "./filters";
export default {
name: "App",
components: {
testFilter,
},
data() {
return {
filters: filters,
test: {},
};
},
};
</script>
so App.vue that holds the filter component and the test value that I want to display and the filters data is dummy data that hold array of objects.
in my test-filter component, I loop throw the filters props and the filterInputs component output the input I want in this case the checkboxes.
test-filter.vue
<template>
<div class="test-filter">
<div
class="test-filter__filter-holder"
v-for="filter in filters"
:key="filter.id"
>
<p class="test-filter__title">
{{ filter.title }}
</p>
<filter-inputs
:value="value"
:filterType="filter.filter_type"
:options="filter.options"
#checkboxChanged="checkboxChanged"
></filter-inputs>
</div>
</div>
<template>
<script>
import filterInputs from "./filterInputs";
export default {
name: "test-filter",
components: {
filterInputs,
},
props:{
filters: {
type: Array,
default: () => [],
},
value: {
type: Array,
default: () => ({}),
},
},
methods:{
checkboxChanged(value){
// Check if there is a array in checkbox key if not asssign an new array.
if (!this.value.checkbox) {
this.value.checkbox = [];
}
this.value.checkbox.push(value)
}
};
</script>
so I need to understand why changing the props value also change to the parent component and in this case the App.vue and I tried to emit the value to the App.vue also the component didn't re-render but if I check the vue dev tool I see the value changed but not in the DOM in {{ test }}.
so I will not be boring you with more code the filterInputs.vue holds child component called checkboxes and from that, I emit the value of selected checkbox from the checkboxes.vue to the filterInputs.vue to the test-filter.vue and every component has the value as props and that it if you want to take a look the rest of components I will be glad if you Did.
filterInpust.vue
<template>
<div>
<check-box
v-if="filterType == checkboxName"
:options="options"
:value="value"
#checkboxChanged="checkboxChanged"
></check-box>
</div>
</template>
<script>
export default {
props: {
value: {
type: Object,
default: () => ({}),
},
options: {
type: Array,
default: () => [],
},
methods: {
checkboxChanged(value) {
this.$emit("checkboxChanged", value);
},
},
}
</script>
checkboxes.vue
<template>
<div>
<div
v-for="checkbox in options"
:key="checkbox.id"
>
<input
type="checkbox"
:id="`id_${_uid}${checkbox.id}`"
#change="checkboxChange"
:value="checkbox"
/>
<label
:for="`id_${_uid}${checkbox.id}`"
>
{{ checkbox.title }}
</label>
</div>
</div>
<template>
<script>
export default {
props: {
value: {
type: Object,
default: () => ({}),
},
options: {
type: Array,
default: () => [],
},
}
methods: {
checkboxChange(event) {
this.$emit("checkboxChanged", event.target.value);
},
},
};
</script>
I found the solution As I said in the comments the problem was that I'm not using v-model in my checkbox input Vue is a really great framework the problem wasn't in the depth, I test the v-model in my checkbox input and I found it re-render the component after I select any checkbox so I search more and found this article and inside of it explained how we can implement v-model in the custom component so that was the solution to my problem and also I update my codeSandbox Example if you want to check it out.
Big Thaks to all who supported me to found the solution: sarkiroka, Jakub A Suplick

(VueJS) Update parent data from child component

I have a parent who's passing props to a child and the child emits events to the parent. However this is not fully working and I am not sure why. Any suggestions?
Parent:
<template>
<div class="natural-language">
<div class="natural-language-content">
<p class="natural-language-results">
<msm-select :options="payments" :model="isShowingUpdate" />
</p>
</div>
</div>
</template>
<script>
import msmSelect from '../form/dropdown.vue'
export default {
components: {
'msm-select': msmSelect
},
data() {
return {
isShowingUpdate: true,
payments: [
{'value': 'paying anuualy', 'text': 'paying anuualy'},
{'value': 'paying monthly', 'text': 'paying monthly'}
],
}
}
}
</script>
Child:
<template>
<div class="form-pseudo-select">
<select :model="flagValue" #change="onChange($event.target.value)">
<option disabled value='Please select'>Please select</option>
<option v-for="(option, index) in options" :value="option.value">{{ option.text }}</option>
</select>
</div>
</template>
<script>
export default {
props: {
options: {
elType: Array
},
isShowingUpdate: {
type: Boolean
}
},
data() {
return {
selected: '',
flagValue: false
}
},
methods: {
onChange(value) {
if (this.selected !== value) {
this.flagValue = true;
} else {
this.flagValue = false;
}
}
},
watch: {
'flagValue': function() {
console.log('it changed');
this.$emit('select', this.flagValue);
}
},
created() {
console.log(this.flagValue);
this.flagValue = this.isShowingUpdate;
}
}
</script>
Basically, when the option in the select box changes, the boolean flag should be updated. However, in my child I am getting undefined for isShowingUpdate. What am I missing?
There isn't the relation that you said between the two components.
The component that you called parent is in reality the child... and the child is parent.
The parent component is always the one that calls the other, in your case:
//Parent component
<template>
...
<msm-select :options="policies" :model="isShowingUpdate" /> << the child
...
</template>
You should change the props/events between the two components.
Edit:
You can edit the:
onChange(value) {
if (this.selected !== value) {
this.flagValue = true;
} else {
this.flagValue = false;
}
}
To a new one like the following:
On the children:
onChange(value) {
if (this.selected !== value) {
this.flagValue = true;
} else {
this.flagValue = false;
}
this.$emit('flagChanged', this.flagValue)
}
On the parent use the emit event to capture and call some other method:
//HTML part:
<msm-select :options="payments" :model="isShowingUpdate" v-on:flagChanged="actionFlagChanged" />
//JS part:
methods: {
actionFlagChanged () {
//what you want
}
}
Can I give you some tips?
It's not a (very) good name of a function the one called: onChange
inside a onChange event... try something like: updateFlag (more
semantic).
I think that you can delete the watch part and do it in the onChange
event
Try to find a good documentation/tutorial (i.e the official documentation) to learn more about parent/child communication.
Remember to add the event-bus import:
import { EventBus } from './event-bus'
Hope it helps!

Passing props dynamically to dynamic component in VueJS

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.

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