How to handle getting new data even? - vue.js

I have got Vue-JS app. After use click variable rasters_previews_list get new data. I would like to generate list with them. I can't understand which directive I should use to handle this even.
Here is my code:
var userContent = Vue.extend({
template: `
<div class="LayersMenuSectionContent" v-if="rasters_previews_list.length">
<ul v-for="img in rasters_previews_list">
<li>{{img.id}}</li> // generate list here
<ul>
</div>
`,
data: function () {
return {
rasters_previews_list: [] // when come new data I should generate li with then
}
},
ready: function()
{
},
methods:
{
}
});
Should I use v-on or v-if?

When rasters_previews_list is changed, list is autorendered in v-for.
new Vue({
el: '#app',
template: `
<div class="LayersMenuSectionContent" v-show="rasters_previews_list.length">
<ul v-for="img in rasters_previews_list">
<li>{{img.id}}</li>
<ul>
</div>
<button #click="add">Add</button>
`,
data: function () {
return {
rasters_previews_list: [] // when come new data I should generate li with then
}
},
ready: function(){ },
methods: {
add(){
this.rasters_previews_list.push({id: 'hello'},{id: 'world'});
}
}
});
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/1.0.26/vue.min.js"></script>
<div id="app"></div>
Extra: You must use v-show instead of v-if for this case

Related

Cant store api data called by axios in array through mounted, unless clicking on <Root> element from vue devtools (in browser)

i'm using axios to get data from api and store in an array after mounting then run a search query in the array later on, but it's not working unless i click on Root element in browsers Vue developer tools, after i click on vue Root element from vue dev tool everything works fine.Here is my code..
<script type="module">
const vueApp = new Vue({
el: "#pos",
data: {
searchTerm: "",
allProducts: [],
selectedProducts: [],
suggestions: []
},
mounted: function (){
axios.get("api/products").then( res => this.allProducts = res.data );
},
methods: {
select(item){
this.selectedProducts.push(item);
this.suggestions = [];
}
},
computed:{
matches(){
if(!this.searchTerm) return;
this.suggestions = this.allProducts.filter(sP=>(sP.prod_name).includes(this.searchTerm));
}
}
});
</script>
//HTML below------------------
<div id="pos">
<input type="text" v-model="searchTerm">
<ul v-for="match in suggestions">
<li #click="select(match)">
{{match.prod_name}}
</li>
</ul>
<table>
<tr v-for="(product,i) in selectedProducts">
<td>#{{product.prod_name}}</td>
</tr>
</table>
</div>
const vueApp = new Vue({
el: "#pos",
data: {
searchTerm: "",
allProducts: [],
selectedProducts: [],
suggestions: []
},
mounted: function() {
axios.get("api/products").then(res => this.allProducts = res.data);
},
methods: {
select(item) {
this.selectedProducts.push(item);
this.suggestions = [];
}
},
computed: {
matches() {
if (!this.searchTerm) return;
this.suggestions = this.allProducts.filter(sP => (sP.prod_name).includes(this.searchTerm));
}
}
});
<div id="pos">
<input type="text" v-model="searchTerm">
<ul v-for="match in suggestions">
<li #click="select(match)">
{{match.prod_name}}
</li>
</ul>
</div>
As I mentioned in the comments on your question, this is an error I cannot seem to understand how you are getting. I sense there is information that we are not being presented with.
As such, here is a quick "working" example of fetching items from the mounted lifecycle hook in a component. Note: If you are creating the component via a Single-File Component (.vue files) then don't worry too much about the declaration, pay attention only to the data and mounted methods.
const App = Vue.component('App', {
template: `<div>
<input v-model="searchTerm" type="search">
{{items.length}} results fetched
</div>`,
data() {
return {
searchTerm: '',
items: []
}
},
mounted() {
//Timeout used to mimic axios query
setTimeout(()=> this.items= [1,2,3,4], 1000)
}
});
const app = new App({
el: '#app'
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">Placeholder</div>
Edit
The code you have given us after your update seems to be working just fine. See the below snippet.
I noticed you are looping over suggestions but that value is never updated anywhere in your given code.
const vueApp = new Vue({
el: "#pos",
data: {
searchTerm: "",
allProducts: [],
selectedProducts: [],
suggestions: []
},
mounted: function() {
setTimeout(() => this.allProducts = [1,2,3,4,5], 1000);
},
methods: {
select(item) {
this.selectedProducts.push(item);
this.suggestions = [];
}
},
computed: {
matches() {
if (!this.searchTerm) return;
this.suggestions = this.allProducts.filter(sP => (sP.prod_name).includes(this.searchTerm));
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="pos">
<input type="text" v-model="searchTerm">
<ul v-for="match in suggestions">
<li #click="select(match)">
{{match.prod_name}}
</li>
</ul>
{{allProducts.length}} results loaded
</div>
mounted: function(){
var _self = this;
axios.get("api/products").then( res => _self.allProducts = res.data );
}

vue.js – get new data information

I'm building a chrome extension using vue.js. In one of my vue components I get tab informations of the current tab and wanna display this information in my template. This is my code:
<template>
<div>
<p>{{ tab.url }}</p>
</div>
</template>
<script>
export default {
data() {
return {
tab: {},
};
},
created: function() {
chrome.tabs.query({ active: true, windowId: chrome.windows.WINDOW_ID_CURRENT }, function(tabs) {
this.tab = tabs[0];
});
},
};
</script>
The Problem is, that the template gets the data before it's filled through the function. What is the best solution for this problem, when the tab data doesn't change after it is set once.
Do I have to use the watched property, although the data is only changed once?
// EDITED:
I've implemented the solution, but it still doesn't work. Here is my code:
<template>
<div>
<div v-if="tabInfo">
<p>set time limit for:</p>
<p>{{ tabInfo.url }}</p>
</div>
<div v-else> loading... </div>
</div>
</template>
<script>
export default {
data() {
return {
tabInfo: null,
};
},
mounted() {
this.getData();
},
methods: {
getData() {
chrome.tabs.query({ active: true, windowId: chrome.windows.WINDOW_ID_CURRENT }, function(tabs) {
console.log(tabs[0]);
this.tabInfo = tabs[0];
});
},
},
};
</script>
The console.log statement in my getData function writes the correct object in the console. But the template only shows the else case (loading...).
// EDIT EDIT
Found the error: I used 'this' in the callback function to reference my data but the context of this inside the callback function is an other one.
So the solution is to use
let self = this;
before the callback function and reference the data with
self.tab
You could initialize tab to null (instead of {}) and use v-if="tabs" in your template, similar to this:
// template
<template>
<div v-if="tab">
{{ tab.label }}
<p>{{ tab.body }}</p>
</div>
</template>
// script
data() {
return {
tab: null,
}
}
new Vue({
el: '#app',
data() {
return {
tab: null,
}
},
mounted() {
this.getData();
},
methods: {
getData() {
fetch('https://reqres.in/api/users/2?delay=1')
.then(resp => resp.json())
.then(user => this.tab = user.data)
.catch(err => console.error(err));
}
}
})
<script src="https://unpkg.com/vue#2.5.17"></script>
<div id="app">
<div v-if="tab">
<img :src="tab.avatar" width="200">
<p>{{tab.first_name}} {{tab.last_name}}</p>
</div>
<div v-else>Loading...</div>
</div>

Is it possible to use inline an $emitted parameter?

In the following code, clicking on the component emits a signal to the parent, who modifies its state inline (in the sense - not via a handler):
Vue.component('my-component', {
template: '<div v-on:click="emitit">click on the component</div>',
methods: {
emitit: function() {
this.$emit('mysignal', 7)
}
}
})
new Vue({
el: "#root",
data: {
from: 0
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.min.js"></script>
<div id="root">
<my-component v-on:mysignal="from=5"></my-component>
from component: {{ from }}
</div>
Is it possible to access the parameter provided via the $emit directly in v-on:mysignal="..."?
I know that I can use a handler defined in the main Vue component but I would like to simplify my code and avoid to have several handlers in methods.
Yes, like this:
<my-component v-on:mysignal="value => from = value"></my-component>
Vue.component('my-component', {
template: '<div v-on:click="emitit">click on the component</div>',
methods: {
emitit: function() {
this.$emit('mysignal', 7)
}
}
})
new Vue({
el: "#root",
data: {
from: 0
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.min.js"></script>
<div id="root">
<my-component v-on:mysignal="value => from = value"></my-component>
from component: {{ from }}
</div>
#click="val => $emit('mysignal', val)"
<div v-on:click="val => $emit('mysignal', val)">click the component</div>'
or even
#click.prevent="e => $emit('mysignal', e.target.value)"

Focus input of freshly added item

So I have a list of items and list of inputs linked to each item via v-for and v-model.
I click a button and add new item to that list. I want to focus input which is linked to newly added item.
Can't figure out how to achieve this goal.
<div id="app">
<div v-for="item in sortedItems">
<input v-model="item">
</div>
<button #click="addItem">
add
</button>
</div>
new Vue({
el: '#app',
data: {
items: []
},
methods: {
addItem: function() {
this.items.push(Math.random());
}
},
computed: {
sortedItems: function() {
return this.items.sort(function(i1, i2) {
return i1 - i2;
})
}
}
})
Here's fiddle with sorted list
https://jsfiddle.net/sfL91r95/1/
Thanks
Update: inspired by pkawiak's comment, a directive-based solution. I found that calling focus in the bind section didn't work; I had to use nextTick to delay it.
Vue.directive('focus-on-create', {
// Note: using Vue 1. In Vue 2, el would be a parameter
bind: function() {
Vue.nextTick(() => {
this.el.focus();
})
}
})
new Vue({
el: '#app',
data: {
items: []
},
methods: {
addItem: function() {
this.items.push(Math.random());
}
},
computed: {
sortedItems: function() {
return this.items.sort(function(i1, i2) {
return i1 - i2;
})
}
}
})
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/1.0.26/vue.min.js"></script>
<div id="app">
<div v-for="item in sortedItems">
<input v-focus-on-create v-model="item">
</div>
<button #click="addItem">
add
</button>
</div>
Original answer:
Make your input a component so that you can give it a ready hook.
const autofocus = Vue.extend({
template: '<input v-model="item" />',
props: ['item'],
ready: function() {
this.$el.focus();
}
})
new Vue({
el: '#app',
data: {
items: []
},
methods: {
addItem: function() {
this.items.push(Math.random());
}
},
components: {
autofocus
},
computed: {
sortedItems: function() {
return this.items.sort(function(i1, i2) {
return i1 - i2;
})
}
}
})
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/1.0.26/vue.min.js"></script>
<div id="app">
<div v-for="item in sortedItems">
<autofocus :item="item"></autofocus>
</div>
<button #click="addItem">
add
</button>
</div>
I Like to extend #Roy's answer.
if you are using any UI framework then it will create DIV and within the DIV input tag will be created so this Snippet will handle that case.
Vue.directive('focus-on-create', {
bind: function(el) {
Vue.nextTick(() => {
el.querySelector('input').focus()
})
}
})

How to display data in template from Vue.extend?

Here is my code:
var guestContent = Vue.extend({
template: `
<p>Guest content</p>
`,
data: function () {
return {
qs: getQuestionsContent(); // here I would like to get in qs data from function
}
}
});
Here is my App.js:
App = new Vue ({ /
el: '#app',
data: {
topMenuView: "guestmenu",
contentView: "guestcontent",
}
});
I need to display qs instead of Guest content and do for example v-for or some kind of other iteration. How can I do it?
Why:
var guestContent = Vue.extend({
template: `
<p>Guest content</p>
<p>{{foo}}</p> // foo not display
`,
data: function () {
foo: "dddddddddd";
}
});
Why is this not working?
Try something like this:
html
<body>
<guest-content></guest-content>
</body>
<template id="guest-content-template">
Guest Content
<ul>
<li v-for="question in questions">
{{question}}
</li>
</ul>
</template>
js
var guestContent = Vue.extend({
template: "#guest-content-template",
data: function (){
return {
questions: []
}
},
ready(){
this.getQuestionsContent();
},
methods:{
getQuestionsContent(){
this.questions = [
"Why?",
"What?",
"When?"
];
}
}
});
Vue.component('guest-content',guestContent);
new Vue({
el:'body'
});
Anything in a {{}} is assumed to be within the current Vue scope, so you just use foo or questions not guestContent.foo.
The data attribute is a function that has to return the data for the app. If you don't return anything, the component wont have any data.