stop vue js watch property from watching sub objects - javascript

Hi this is my code,
var vm = new Vue({
el: '#el',
data: {
input: {
sorting: "",
brand: null,
model: null,
country: "all",
cap: "",
radius: ""
}
},
watch: {
input: {
handler(newInput) {
},
deep: true
}
}
});
Here I'm watching weather input object changes. But I need to watch only some items only input object. For example I need to do something if input.country changes but not when input.brand changes. Unfortunately my code is complex and can't take items out of input object.

Just watch what you need:
watch: {
'input.country': {
handler(newCountry) {
}
}
}

Declare a computed value who target this.item.country:
computed: {
itemCountry() {
return this.item.country;
}
}
And watch this new computed value:
watch: {
itemCountry: {
immediate: true,
handler(newInput) {
// do your stuff
}
}
}

Related

VueJS : how to set a default value of a key / value in a prop of type array?

I'm learning Vue JS and I am creating my components.
I'm stuck on an issue.
I would like to have my component taking in params an array of object like that :
data() {
return {
items: [
{
text: 'Admin',
href: '#'
},
{
text: 'Manage',
href: '#'
},
{
text: 'Library',
active: true
}
]
}
So, I tried to implement my component with props :
props: {
items: {
type: Array,
required: true
}
However, I have no idea how to say that : if items does not contains active key, then it should have a false default value.
If you have any advices/links or explanations, I will be very grateful to you.
You can make a computed property which will fill-in those active: false by default, and override it with the provided items:
props: {
items: {
type: Array,
required: true
}
},
computed: {
normalizedItems() {
return this.items.map(x => ({ active: false, ...x }));
}
}
You would then use normalizedItems in your template instead of items

Computed property in a v-loop workaround

I'm trying to make the code below work knowing that computed properties can't take parameters. Do you have any idea ? I'm exploring the use of watchers on functions but I was wondering if there was not an easier solution to do this.
var app = new Vue({
el: '#app',
data() {
return {
sessions: {
"156": {
tickets: {
"01": {
available: true,
},
"02": {
available: false,
},
}
},
},
tickets: {
"01": {
attr: "somestring",
},
"02": {
attr: "someotherstring",
},
},
},
};
},
computed: {
sessionTickets(session) {
let _this = this;
let sessionTickets = {};
$.each(_this.session.tickets, function(ticketId, sessionTicket) {
if(sessionTicket.available) {
sessionTickets[ticketId] = _this.tickets[ticketId];
}
});
return sessionTickets;
},
},
});
<div v-for="session in sessions">
<div v-for="sessionTicket in sessionTickets(session)">
{{ sessionTicket.attr }}
</div>
</div>
Thanks to "WallOp" for making me realize that my computed property is in a sessions loop and so it can normally become a class method and be refreshed on sessions refresh !
I think you can use computed property. Just filter tickets of sessions. Like this:
var app = new Vue({
el: '#app',
data() {
return {
sessions: {
"156": {
tickets: {
"01": {
available: true,
},
"02": {
available: false,
},
}
},
},
tickets: {
"01": {
attr: "somestring",
},
"02": {
attr: "someotherstring",
},
},
},
};
computed: {
filteredSessions() {
return this.sessions.map( session => {
let tickets = {};
for(key in session.tickets) {
if(session.tickets[key].available && this.tickets.hasOwnProperty(key)) {
tickets[key] = this.tickets[key];
}
}
session.tickets = tickets;
return session;
});
},
},
});
<div v-for="session in filteredSessions">
<div v-for="ticket in session.tickets">
{{ ticket.attr }}
</div>
</div>

Ignore some properties in a deep watch for VueJs

I'm working on an autosave feature for a vue app that sends data to api every time a change is made to the vue app data. Is it possible to ignore certain properties of an objected when using a vue watch? The object has multiple values that I want to watch to auto save and only 1 or 2 that would be ignore so it doesn't seem to make sense to set up a watch function for all the properties I want but instead just ignore the 1 that I don't.
This is the basic structure of the data:
data:{
template: {
name: "Template",
id: 1,
variables: [
{
name: "v1",
color: "#fff",
group: 1,
isSelected: true
},
{
name: "v2",
color: "#fff",
group: 3,
isSelected: false
}
]
}
}
and the basic watch function:
watch: {
template: {
handler: function(){
this.save();
},
deep: true
}
}
The isSelected field for the variables in the template are used for UI purposed only and I would like the watch to ignore that field changing because they don't get saved. I don't want to have to set up a watch function for every field in variables but instead do something in the watch like:
ignore: "template.variables.isSelected"
You can't get old value for mutation object so I think creating some helper data as below temp(save old data) will help your problem .Then check old and new data ....
var app = new Vue({
el: "#app",
data:{
a: 1,
template: {
name: "Template",
id: 1,
variables: [
{
name: "v1",
color: "#fff",
group: 1,
isSelected: true
},
{
name: "v2",
color: "#fff",
group: 3,
isSelected: false
}
]
},
temp: {}
},
mounted: function() {
// this.template.variables[0].isSelected = false;
this.temp = JSON.parse(JSON.stringify(this.template));
this.$set(this.template.variables[0],"isSelected", 222);
},
watch : {
template: {
handler: function(changeVal) {
var flag = true;
for(var i in changeVal.variables) {
if(changeVal.variables[i].isSelected != this.temp.variables[i].isSelected) {
flag = false;
}
}
this.temp = JSON.parse(JSON.stringify(this.template)); // assign changed data as old data again for next process
if(flag) console.log("saveData");// this.save();
else console.log("notsave");
},
deep: true
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app"></div>

How to set pre-selected value in vue js dropdownlist

I'm working on two vue component.sending parent component array data to child component using props.now i want to set pre-selected value in child component dropdownlist.
Here is my code sample:
props:{
// pre-selected value based on this.
userdata:{
type:[Array,Object],
required:true,
},
roles:{
type:[Array,Object],
required:true,
},
},
data(){
return{
mutableRoles:[],
}
},
and this is my view part:
//i want set pre-selected value on this dropdownlist
<select multiple v-model="mutableRoles" class="form-control">
<option v-for="(role,index) in roles" v-bind:value="role.id" >{{role.name}}</option>
</select>
I have seen many example where show only using string. but in my case both are array.
Try this:
const CurrentRole = Vue.component("current-role", {
template: `
<div>
<label>Options</label>
<select v-model="roleId" #change="changeValue">
<option v-for="v in roles" :key="v.id" :value="v.id">{{v.title}}</option>
</select>
</div>
`,
props: {
userdata: {
type: [Array, Object],
required: true,
},
roles: {
type: [Array, Object],
required: true,
}
},
data: _ => ({
roleId: null
}),
methods: {
changeValue() {
this.userdata.role = this.roles.find(e => e.id == this.roleId)
},
},
mounted() { // for initial state
this.roleId = this.userdata.role.id
},
watch: {
userdata(v) { // for changes on parent
if (v) this.roleId = v.role.id
}
}
})
new Vue({
el: "#app",
data: {
rlist: [{
id: 1,
title: "a"
}, {
id: 2,
title: "b"
}, {
id: 3,
title: "c"
}],
user: {
role: {
id: 3,
title: "c"
}
}
},
methods: {
changeUser() {
this.user = {
role: {
id: 1,
title: "a"
}
}
}
}
})
<script src="https://unpkg.com/vue#2.5.22/dist/vue.js"></script>
<div id="app">
<p>User: {{user}}</p>
<current-role :userdata="user" :roles="rlist">
</current-role/>
<button #click="changeUser">change user</button>
</div>
The select is tailored for primitive values, therefore you'll need to add helper functions.
Higher level vue frameworks such as vue-material, vuetify, element and muse-ui tend to offer components to cope with such problems with a higher abstraction level.
EDIT:
I changed the snippet in order to make it closer to your situation.

Extending Vue component results in multiple GET calls

I have a Base Vue Component, which handles items. Now i've extended that component with a CompanyItem and a EducationItem. But when i load both the directives, it will call a GET method 4 times. Also: i have a click handler on 2 models (example: openUpdateOrCreateModal()) which is loaded in one of the directives. When i click, the other directive is triggered too. Anyone a idea?
Base
module.exports = {
props: ['user', 'update_url', 'store_url', 'delete_url', 'show_url', 'index_url', 'item_type'],
mounted() {
Bus.$emit('index');
},
data(){
return {
form: {},
items: [],
mainItem: {},
item: {},
}
},
created(){
},
methods: {
resetForm(){
this.form = new SparkForm({
general: {
title: null,
},
item: this.getItemProperties(),
address: {
address_line_1: null,
address_line_2: null,
city: null,
province: null,
zip_code: null
}
});
this.mainItem = null;
},
getItemProperties(){
return {};
},
showModal(){
$('#create-update-'+this.item_type+'-modal').modal('show');
},
hideModal(){
$('#create-update-'+this.item_type+'-modal').modal('hide');
},
/**
* Gets a list with specific items
*/
index(){
console.log('Call index');
axios.get(this.index_url)
.then(response =>
{
this.items = response.data.data;
});
},
}
};
Education
var base = require('./cv-item-base');
Vue.component('cv-educations-management', {
mixins: [base],
methods: {
getItemProperties(){
return {
start_at: null,
end_at: null,
description: null,
finished_education: null,
level: null,
}
}
}
});
Companies
var base = require('./cv-item-base');
Vue.component('cv-company-list', {
mixins: [base],
methods: {
getItemProperties(){
return {
start_at: null,
end_at: null,
position: null,
description: null,
phone_number: null,
branch: null,
referral: null,
}
}
}
});
HTML
<cv-company-management :user="user"
:update_url="'{{route('application.manage.companies.update')}}'"
:show_url="'{{route('application.manage.companies.show')}}'"
:delete_url="'{{route('application.manage.companies.destroy')}}'"
:store_url="'{{route('application.manage.companies.store')}}'"
:index_url="'{{route('application.manage.companies.index')}}'"
:item_type="'company'"
inline-template>
</cv-company-management>
<cv-education-management :user="user"
:update_url="'{{route('application.manage.educations.update')}}'"
:show_url="'{{route('application.manage.educations.show')}}'"
:delete_url="'{{route('application.manage.educations.destroy')}}'"
:store_url="'{{route('application.manage.educations.store')}}'"
:index_url="'{{route('application.manage.educations.index')}}'"
:item_type="'education'"
inline-template>
</cv-education-management>

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