How to count the selected checboxes with VueJS - vuejs2

i am new to VueJS and i am trying to make a dropdown list where it contains a few checkboxes with a button to select them all and an event click on each box to bind the click, and finaly i want to count the checked boxes in a <p>{{selected}}</p> tag.
<p>{{selected}}</p>
<div class="uk-card uk-card-default uk-card-body" v-for="(data, value) in filteredList">
<label><input class="uk-checkbox" type="checkbox" v-model="allChecked" :value="data.id" v-on:click="select(data, value)">{{data.name}}</label>
</div>
<div class="uk-inline">
<label>
<input type="checkbox" id="sAll" class="switchButton uk-button uk-button-default" value="Отметить все" v-model="checkAll">
</label>
</div>
var menu = new Vue(
{
el: "#main_menu",
data: function () {
return {
allChecked: [],
selectedList: [],
selected: 0,
selections: [{id:1, name:"first"},{id:2, name:"second"},{id:3, name:"third"}]
}
},
methods: {
select: function(data, id){
console.log(this.selectedList);
if(this.selectedList.includes(data.name)){
this.selectedList.splice(id);
} else {
this.selectedList.push(data.name);
}
this.selected = this.selectedList.length;
}
},
computed: {
checkAll: {
get: function(){
return this.selections ? this.allChecked.length == this.selections.length: false;
},
set: function(value){
var allChecked = [];
if(value){
this.selections.forEach(function(item){
allChecked.push(item.id);
});
}
this.allChecked = allChecked;
this.selectedList = allChecked;
this.selected = allChecked.length;
}
}
}
}
)

So i think it will be easier for you to handle this with adding a property to your list items and then derive the other things.
options: [{id:1, name:"", selected: BOOLEAN}]
Once you do that then all of the other things you are needing are a function of working on that list instead of editing state on multiple variables.
For each checkbox, set the value of the checkbox to the boolean value of the option
On checkbox click call a function that is toggleOption(id), create that method to handle the toggling for finding by id and toggling its selected state
On selectAll, loop through the list of options and set all of them to selected of true, deselectAll is the opposite
To get the list of selected, create a computed property that selects all the options that are selected

Related

When data is changed within the watch function, dom does not update

Below is the data in a component
data: function () {
return {
sltAreaStyle: {
paddingTop: "3%",
},
checkedTypes: ["krw", "btc", "usdt"],
};
},
Below is watch function of checkedTypes data
watch: {
checkedTypes: {
handler: function (newVal, oldVal) {
if (newVal.length < 1) {
alert("Choose one or more.");
var last = oldVal[0];
this.$data.checkedTypes = [last];
}
},
},
},
Below is my html template
<div class="ckbxArea">
<input type="checkbox" value="krw" v-model="checkedTypes">KRW</input>
<input type="checkbox" value="btc" v-model="checkedTypes">BTC</input>
<input type="checkbox" value="usdt" v-model="checkedTypes">USDT</input>
</div>
I want to change the last value to checkedTypes data when all the check boxes are unchecked.
If the first checkbox was finally unchecked, the checkedTypes would be 'krw' like checkedTypes = ['krw'] The checkedTypes data is ['krw'], but all checkbox tags are unchecked. That is, dom has not been updated. I don't think I understand Vue's life cycle well. I think this problem is related to the life cycle of v-model and components, but I don't know what the problem is. Please explain why this problem occurs and tell me how to solve it.
Well this is more about Vue rendering mechanisms for v-modeleld input controls.
Check this:
Only one last checkbox is checked so model value is ['krw']
Uncheck last checkbox
Watcher is executed - new model value is [] BUT the watcher immediately sets it to same value as before ... ['krw']
Vue re renders the template (see the message in the console) BUT as the v-model value is same as during last render, it does not update the checkbox
Simple solution to situations like this is to postpone the update to next rendering cycle using nextTick
this.$nextTick(() => {
this.checkedTypes = [last];
})
new Vue({
el: "#app",
data: function () {
return {
checkedTypes: ["krw", "btc", "usdt"],
};
},
updated() {
console.log("Component updated")
},
watch: {
checkedTypes: {
handler: function (newVal, oldVal) {
if (newVal.length < 1) {
alert("Choose one or more.");
//console.log("Choose one or more.");
var last = oldVal[0];
// this.checkedTypes = [last];
this.$nextTick(() => {
this.checkedTypes = [last];
})
}
},
},
},
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.6.14/vue.js"></script>
<div id="app">
<input type="checkbox" value="krw" v-model="checkedTypes"/> KRW
<input type="checkbox" value="btc" v-model="checkedTypes"/> BTC
<input type="checkbox" value="usdt" v-model="checkedTypes"/> USDT
<pre>{{ checkedTypes }}</pre>
</div>

Filtering a list of objects in Vue without altering the original data

I am diving into Vue for the first time and trying to make a simple filter component that takes a data object from an API and filters it.
The code below works but i cant find a way to "reset" the filter without doing another API call, making me think im approaching this wrong.
Is a Show/hide in the DOM better than altering the data object?
HTML
<button v-on:click="filterCats('Print')">Print</button>
<div class="list-item" v-for="asset in filteredData">
<a>{{ asset.title.rendered }}</a>
</div>
Javascript
export default {
data() {
return {
assets: {}
}
},
methods: {
filterCats: function (cat) {
var items = this.assets
var result = {}
Object.keys(items).forEach(key => {
const item = items[key]
if (item.cat_names.some(cat_names => cat_names === cat)) {
result[key] = item
}
})
this.assets = result
}
},
computed: {
filteredData: function () {
return this.assets
}
},
}
Is a Show/hide in the DOM better than altering the data object?
Not at all. Altering the data is the "Vue way".
You don't need to modify assets to filter it.
The recommended way of doing that is using a computed property: you would create a filteredData computed property that depends on the cat data property. Whenever you change the value of cat, the filteredData will be recalculated automatically (filtering this.assets using the current content of cat).
Something like below:
new Vue({
el: '#app',
data() {
return {
cat: null,
assets: {
one: {cat_names: ['Print'], title: {rendered: 'one'}},
two: {cat_names: ['Two'], title: {rendered: 'two'}},
three: {cat_names: ['Three'], title: {rendered: 'three'}}
}
}
},
computed: {
filteredData: function () {
if (this.cat == null) { return this.assets; } // no filtering
var items = this.assets;
var result = {}
Object.keys(items).forEach(key => {
const item = items[key]
if (item.cat_names.some(cat_names => cat_names === this.cat)) {
result[key] = item
}
})
return result;
}
},
})
<script src="https://unpkg.com/vue"></script>
<div id="app">
<button v-on:click="cat = 'Print'">Print</button>
<div class="list-item" v-for="asset in filteredData">
<a>{{ asset.title.rendered }}</a>
</div>
</div>

Is it possible to detect if a change event was triggered by a click on a Vue select element?

I have a <select>-element that has a data property bound to it using v-model in Vue.
Sometimes I want to change that value dynamically. I also have an event-listener attached to this element which is triggered on the change-event. See code example:
<template>
<div class="mySelector">
<select id="testSelect" v-model="mySelectModel"
#change="onChange($event)">
<template v-for="(item, index) in someList">
<option :class="['btn', 'btn-default', 'removing-button']" :value="index">{{item.name}}</option>
</template>
</select>
</div>
</template>
<script>
export default {
data() {
return {
mySelectModel: null
}
},
props: {
},
methods: {
customChange: function() {
this.mySelectModel = ... // some value we from somewhere else that is set dynamically on some condiftion
},
onChange: function (event) {
if (!event) return;
// DO SOMETHING THAT WE ONLY WANT TO DO ON A REAL CLICK
}
},
}
</script>
The problem I have is that when I change the data value mySelectModel dynamically, like in the customChange-method, the change event is also called, triggering the method onChange. I only want to do stuff in that method if it was really triggered by a real click, not when it was changed dynamically.
I can not find a way to distinguish between those cases when the change-event is triggered by a click or when it is just changed for some other reason. Any suggestions?
See vue-js-selected-doesnt-triggering-change-event-select-option, it appears that select does not trigger #change when v-model is updated by JS (only when the selected value is changed by user).
A directive can add the functionality
Vue.directive('binding-change', {
update: function (el, binding, vnode) {
const model = vnode.data.directives.find(d => d.name === 'model')
if (model) {
binding.value(model.value)
}
}
})
use like
<select id="testSelect"
v-binding-change="onChange"
v-model="mySelectModel"
#change="onChange($event)">
Not sure about the parameter to onChange - I'll give it a test.
Similar to this suggested solution, you can make a settable computed that you v-model in your widget:
The get function simply returns the data item
The set function does whatever you want a change in the widget to do, in addition to setting the data item
Other code can change the data item directly and will not execute the set code of the computed.
new Vue({
el: '#app',
data: {
values: ['one','two','three'],
selectedItem: 'two'
},
computed: {
wrappedSelectedItem: {
get() { return this.selectedItem; },
set(value) {
console.log("Changed in widget");
this.selectedItem = value;
}
}
},
methods: {
changeToThree() {
console.log("Stealth change!");
this.selectedItem = 'three';
}
}
});
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/2.4.2/vue.min.js"></script>
<div id="app">
<select v-model="wrappedSelectedItem">
<option v-for="value in values" :value="value">{{value}}</option>
</select>
<button #click="changeToThree">Set to three</button>
</div>

how to do filters in vue.js

i am new to vue.js.so i want to apply a filter thing in my project.i tried to do this from past 2 to 3 days..but i couldn't..can any one help me how to do this..
I have 3 input boxes one is experience,expected_ctc,and profile_role depending on these 3 i want to display the results..
Here is my js page:
const app = new Vue({
el: '#app',
data() {
return {
page: 0,
itemsPerPage: 3,
}
},
components: { Candidate },
methods: {
//custom method bound to page buttons
setPage(page) {
this.page = page-1;
this.paginedCandidates = this.paginate()
},
paginate() {
return this.filteredCandidates.slice(this.page * this.itemsPerPage, this.page * this.itemsPerPage + this.itemsPerPage)
},
},
computed: {
//compute number of pages, we always round up (ceil)
numPages() {
console.log(this.filteredCandidates)
return Math.ceil(this.filteredCandidates.length/this.itemsPerPage);
},
filteredCandidates() {
//filter out all candidates that have experience less than 10
const filtered = window.data.candidates.filter((candidate) => {
if(candidate.experience === 5) {
return false;
}
return true;
})
console.log(filtered);
return filtered;
},
paginedCandidates() {
return this.paginate()
}
}
});
here is my buttons from view page:
<div class="container">
<b>Experience:</b><input type="text" v-model="experience" placeholder="enter experience">
<b>Expected CTC:</b><input type="text" v-model="expected_ctc" placeholder="enter expected ctc">
<b>Profile Role:</b><input type="text" v-model="profile_role_id" placeholder="enter role">
<input type="button" name="search" value="search" >
</div>
Can anyone help me..
Thanks in advance..
Ok let's start with a smaller example. Lets say you have "Candidates" one one candidate might look like
{
name: 'John Doe',
expected_ctc: 'A',
experience: 'B',
profile_role_id: 1
}
From your current state I'd say you have all candidates in an array returned by laravel. Let's say we're in your current template where you have your vue app
<div id="app">
<!-- lets start with one filter (to keept it clean) -->
<input type="text" v-model="experienceSearch"/>
<ul class="result-list">
<li v-for="result in candidatelist">{{ result.name }}</li>
</ul>
</div>
And now to the script
// always init your v-model bound props in data
// usually you wouldn't take the candidates from the window prop. However, to keep it easy for you here I will stick to this
data: function() {
return {
experienceSearch: '',
candidates: window.data.candidates
}
},
// the list that is displayed can be defined as computed property. It will re-compute everytime your input changes
computed: {
candidatelist: function() {
// now define how your list is filtered
return this.candidates.filter(function(oCandidate) {
var matches = true;
if (this.experienceSearch) {
if (oCandidate.experience != this.experienceSearch) {
matches = false;
}
}
// here you can define conditions for your other matchers
return matches;
}.bind(this));
}
}
General steps:
all candidates are in data -> candidates
relevant (filtered) candidates are represented by the computed prop candidatelist
inputs are bound with v-model to EXISTING data prop definitions
Fiddle https://jsfiddle.net/sLLk4u2a/
(Search is only exact and Case Sensitive)

vue.js: Tracking currently selected row

I have a simple table where I would like to handle click elements:
<div class="row"
v-bind:class="{selected: isSelected}"
v-for="scanner in scanners"
v-on:click="scannerFilter">
{{scanner.id}} ...
</div>
JS:
new Vue({
el: "#checkInScannersHolder",
data: {
scanners: [],
loading: true
},
methods: {
scannerFilter: function(event) {
// isSelected for current row
this.isSelected = true;
// unselecting all other rows?
}
}
});
My problem is unselecting all other rows when some row is clicked and selected.
Also, I would be interested to know, it it is possible accessing the scanner via some variable of the callback function instead of using this as I might need to access the current context.
The problem is you have only one variable isSelected using which you want to control all the rows. a better approach will be to have variable: selectedScanner, and set it to selected scanner and use this in v-bind:class like this:
<div class="row"
v-bind:class="{selected: selectedScanner === scanner}"
v-for="scanner in scanners"
v-on:click="scannerFilter(scanner)">
{{scanner.id}} ...
</div>
JS
new Vue({
el: "#checkInScannersHolder",
data: {
scanners: [],
selectedScanner: null,
loading: true
},
methods: {
scannerFilter: function(scanner) {
this.selectedScanner = scanner;
}
}
});
I was under the impression you wanted to be able to selected multiple rows. So here's an answer for that.
this.isSelected isn't tied to just a single scanner here. It is tied to your entire Vue instance.
If you were to make each scanner it's own component your code could pretty much work.
Vue.component('scanner', {
template: '<div class="{ selected: isSelected }" #click="toggle">...</div>',
data: function () {
return {
isSelected: false,
}
},
methods: {
toggle () {
this.isSelected = !this.isSelected
},
},
})
// Your Code without the scannerFilter method...
Then, you can do:
<scanner v-for="scanner in scanners"></scanner>
If you wanted to keep it to a single VM you can keep the selected scanners in an array and toggle the class based on if that element is in the array or not you can add something like this to your Vue instance.
<div
:class="['row', { selected: selectedScanners.indexOf(scanner) !== 1 }]"
v-for="scanner in scanners"
#click="toggle(scanner)">
...
</div>
...
data: {
return {
selectedScanners: [],
...
}
},
methods: {
toggle (scanner) {
var scannerIndex = selectedScanners.indexOf(scanner);
if (scannerIndex !== -1) {
selectedScanners.splice(scannerIndex, 1)
} else {
selectedScanners.push(scanner)
}
},
},
...