Develop Reference

Commit initial array to store when leaving page, but if pressing back button loads last commited array

I have an array of articles that can be filtered based on their category. If you click the filter for "ideas" it will filter the array into a new array, let's say "ideasFiltered" and then i commit it to my store "filteredArticles". If i leave the page and press back it is saving that info. Yay! Great! BUT, let's say i go to a new page in my website and then i click my news page again, it has still saved that last commit "ideasFiltered". Is there a way to only save that data if you are pressing "back" in the browser or pressing "back to articles" out of one of my articles (i have a button that let's you go back to the list of articles on each article page), but if you click to a different link in my site it will reset to my full article list?
here is my store:
const store = new Vuex.Store({
state: {
filteredArticles: this.articles
},
mutations: {
setFilteredList (state, value) {
state.filteredArticles = value
}
},
plugins: [
createPersistedState()
],
})
my computed:
computed: {
filteredArticles () {
return store.state.filteredArticles
}
}
so if you click one of my filtered is runs a script, here is an example of the ideas script
ideas: function ideas() {
this.$store.commit('setFilteredList', articles) **// resetting to the full list before filtering**
var ideasFiltered = this.filteredArticles.filter(function(post) {
return post.category === 'Ideas';
});
this.filteredCategory = 'ideas'; **// this is used to add the category to my url**
this.$store.commit('setFilteredList', ideasFiltered) **// committing to the store**
}
here is my html, not sure if it is really necessary though
<div class="news-article-list">
<ul>
<li v-for="(article, index) in filteredArticles" :key="index">
<a :href="article.url">
<img :src="article.featureImg" v-if="article.featureImg" alt="Article Feature Image" />
<h2 class="news-title">{{ article.title }}</h2>
<p class="news-date">{{ article.date }}</p>
<p class="short-desc">{{ article.shortDesc }}...</p>
</a>
<router-link class="read-more" :to="article.url">Read More</router-link>
</li>
</ul>
</div>
Let me know if i need to explain any further. I need it to commit ALL articles if going to a different page on my site and clicking news to get back to the news page, but saving the FILTERED article list if you go to an article and click back.
thanks in advance!

I wouldn't worry about detecting the back button. What you want to know where from did the user come and where to the user wants to go. to and from are your routes. ideasFiltered is changed permanently until you clear it manually. To handle clearing it yourself, create an action in vue-router that resets the data in ideasFiltered and then dispatch that action depending on what route the user is on. You can add a watch in your Vue component to watch the global vue-router $router. In Vue.js 3 its like this:
import {useRoute} from 'vue-router';
import {useStore} from 'vuex';
....
setup() {
const $route = useRoute();
const $store = useStore();
watch(() => $route.name, async () => {
// If the user is not on News or Articles route, then tell store to reset filtered list
if ($route.name !=== "News" || $route.name !=== "Articles") {
$store.dispatch('clearFilteredList', null) // You need to create this action in your store
},
{
deep: true,
immediate: true
}
)
}
The mutation and action in $store to be committed would be something like:
mutations: {
setFilteredList (state, value) { // value passed should be null
state.filteredArticles = value
}
actions: {
clearFilteredList({commit}, payload) { // This is null from Vue component remember!
commit('setFilteredList', payload) // sets it to null
}
I can't see your full store code so the above answer is a best guess but should give you an idea how to go about it. You don't have to use null, you could use make it an empty array or object e.g. []

Working with Vuex with Vue and displaying data

This is kind of a long explanation of an issue that I'm having on a personal project. Basically, I want to set a data property before my page loads when I read in data from a CSV file using D3.JS. I almost have it done but running into a small issue. Please read on to get more detail.
Basically, when the user comes to a page in my application, I want to display weather graphs. Like I said, I'm using D3.js to read in the data and created an action to do that. It works perfectly fine-I can console.log the data and I know its been read. However, in my vue instance I have a data property, which would hold the data set like this:
data() {
return {
name: this.$store.state.name
weatherData: this.$store.state.yearData
}
}
I then want to ensure that the weatherData is filled, with data from the csv file so I display it on the page like this:
<p>{{ weatherData }}</p>
Nothing special here. When the page loads, weatherData is blank. But I have a beforeMount life cycle hook and if I comment out the only line in it then it will display the data. If I then refresh the page, fire the action to get the data and then uncomment out the line in the beforeMount hook then the data appears! So before I continue this is my full code for the store:
export const store = new Vuex.Store({
state: {
name: 'Weather Data'
yearData: []
},
getters: {
},
mutations: {
setYearData(state, data) {
state.yearData = data
}
},
actions: {
getYearData: ({commit}) => {
d3.csv("../src/components/data/alaska.csv")
.then(function(data){
let yearData = []
for (let i = 0; i < data.length; i++){
let day = data[i].AKST
yearData.push(day)
}
//console.log(yearData)
commit('setYearData', yearData)
})
}
})
Here are parts of the vue file: The template:
<p>{{ weatherData }}</p>
The Vue Intance:
export default {
name: 'Weather',
data() {
return {
name: this.$store.state.name,
weatherData: this.$store.state.yearData
}
},
methods: {
...mapActions([
'getYearData'
])
},
beforeMount(){
this.$store.dispatch('getYearData') //(un)Commenting out this line will make my data appear
}
}
Page when it loads: Notice empty array:
Then either comment out or comment the one line in the beforeMount hook and get this: THE DATA!!!
Again, my end goal is to have the action called and the data set before the page finishes loading. Finally, I know that I don't need VUEX but this project is further helping me understand it. Any guidance on why this is happening would be great.

use mapState instead of putting your data in the data object, which sometimes being late on updating the template.
just make your Vue instance to look like:
import {mapState} from 'vuex'
export default {
name: 'Weather',
data() {
return { }
},
computed:{
...mapState({
name: state=>state.name,
weatherData: state=>state.yearData
})
},
methods: {
...mapActions([
'getYearData'
])
},
beforeMount(){
this.$store.dispatch('getYearData') //(un)Commenting out this line will make my data appear
}
thats way, you work directly with one source of truth-the store, and your name and weatherData will be reactive as well.
more about mapState here: https://vuex.vuejs.org/guide/state.html#the-mapstate-helper

How to route to specific div in a component in vuejs 2

My routes for the application are
const router = new VueRouter({
mode:'history',
routes:[
{
path:'/home',
name:'home',
component: Home
},
{
path: '/services',
name: 'services',
component: Services
},
{
path:'/blogs',
name:'blogs',
component:Blogs
},
{
path:'/pingme',
name:'pingme',
component:Pingme
}
],
})
Now, in services route I want to navigate to the which is present in the Home component. How can I create router so as to navigate to the services div when the services link is clicked?

Let's say you want to bring in focus to a specific div in the Service component.
we will make use of query params to achive this. You add add a dedicated url as well which will do this.
This is my route:
{
path: '/services',
name: 'services',
component: Services
}
Then in the url localhost:8000/services?show=mydiv and in the mounted hook of the component do something like this:
mounted() {
// add a id to the div we want to bring in foucs
// and id and the id is paased the query params
document.getElementById(this.$route.query.show).scrollIntoView()
}
Let me know if it works for you.
Edit
Another way we can make this work is by using a watcher and a computed property.
First add a computed property for the show query param in the route.
computed: {
show() { return this.$router.query.show }
}
Then add a watcher to trigger the focus.
watch: {
show: {
immediate: true,
handler(value) {
document.getElementById(value).scrollIntoView();
}
}
That should work in all cases.

Passing data to components in vue.js

I'm struggling to understand how to pass data between components in vue.js. I have read through the docs several times and looked at many vue related questions and tutorials, but I'm still not getting it.
To wrap my head around this, I am hoping for help completing a pretty simple example
display a list of users in one component (done)
send the user data to a new component when a link is clicked (done) - see update at bottom.
edit user data and send it back to original component (haven't gotten this far)
Here is a fiddle, which fails on step two: https://jsfiddle.net/retrogradeMT/d1a8hps0/
I understand that I need to use props to pass data to the new component, but I'm not sure how to functionally do it. How do I bind the data to the new component?
HTML:
<div id="page-content">
<router-view></router-view>
</div>
<template id="userBlock" >
<ul>
<li v-for="user in users">{{user.name}} - <a v-link="{ path: '/new' }"> Show new component</a>
</li>
</ul>
</template>
<template id="newtemp" :name ="{{user.name}}">
<form>
<label>Name: </label><input v-model="name">
<input type="submit" value="Submit">
</form>
</template>
js for main component:
Vue.component('app-page', {
template: '#userBlock',
data: function() {
return{
users: []
}
},
ready: function () {
this.fetchUsers();
},
methods: {
fetchUsers: function(){
var users = [
{
id: 1,
name: 'tom'
},
{
id: 2,
name: 'brian'
},
{
id: 3,
name: 'sam'
},
];
this.$set('users', users);
}
}
})
JS for second component:
Vue.component('newtemp', {
template: '#newtemp',
props: 'name',
data: function() {
return {
name: name,
}
},
})
UPDATE
Ok, I've got the second step figured out. Here is a new fiddle showing the progress: https://jsfiddle.net/retrogradeMT/9pffnmjp/
Because I'm using Vue-router, I don't use props to send the data to a new component. Instead, I need set params on the v-link and then use a transition hook to accept it.
V-link changes see named routes in vue-router docs:
<a v-link="{ name: 'new', params: { name: user.name }}"> Show new component</a>
Then on the component, add data to the route options see transition hooks:
Vue.component('newtemp', {
template: '#newtemp',
route: {
data: function(transition) {
transition.next({
// saving the id which is passed in url
name: transition.to.params.name
});
}
},
data: function() {
return {
name:name,
}
},
})

-------------Following is applicable only to Vue 1 --------------
Passing data can be done in multiple ways. The method depends on the type of use.
If you want to pass data from your html while you add a new component. That is done using props.
<my-component prop-name="value"></my-component>
This prop value will be available to your component only if you add the prop name prop-name to your props attribute.
When data is passed from a component to another component because of some dynamic or static event. That is done by using event dispatchers and broadcasters. So for example if you have a component structure like this:
<my-parent>
<my-child-A></my-child-A>
<my-child-B></my-child-B>
</my-parent>
And you want to send data from <my-child-A> to <my-child-B> then in <my-child-A> you will have to dispatch an event:
this.$dispatch('event_name', data);
This event will travel all the way up the parent chain. And from whichever parent you have a branch toward <my-child-B> you broadcast the event along with the data. So in the parent:
events:{
'event_name' : function(data){
this.$broadcast('event_name', data);
},
Now this broadcast will travel down the child chain. And at whichever child you want to grab the event, in our case <my-child-B> we will add another event:
events: {
'event_name' : function(data){
// Your code.
},
},
The third way to pass data is through parameters in v-links. This method is used when components chains are completely destroyed or in cases when the URI changes. And i can see you already understand them.
Decide what type of data communication you want, and choose appropriately.

The best way to send data from a parent component to a child is using props.
Passing data from parent to child via props
Declare props (array or object) in the child
Pass it to the child via <child :name="variableOnParent">
See demo below:
Vue.component('child-comp', {
props: ['message'], // declare the props
template: '<p>At child-comp, using props in the template: {{ message }}</p>',
mounted: function () {
console.log('The props are also available in JS:', this.message);
}
})
new Vue({
el: '#app',
data: {
variableAtParent: 'DATA FROM PARENT!'
}
})
<script src="https://unpkg.com/vue#2.5.13/dist/vue.min.js"></script>
<div id="app">
<p>At Parent: {{ variableAtParent }}<br>And is reactive (edit it) <input v-model="variableAtParent"></p>
<child-comp :message="variableAtParent"></child-comp>
</div>

I think the issue is here:
<template id="newtemp" :name ="{{user.name}}">
When you prefix the prop with : you are indicating to Vue that it is a variable, not a string. So you don't need the {{}} around user.name. Try:
<template id="newtemp" :name ="user.name">
EDIT-----
The above is true, but the bigger issue here is that when you change the URL and go to a new route, the original component disappears. In order to have the second component edit the parent data, the second component would need to be a child component of the first one, or just a part of the same component.

The above-mentioned responses work well but if you want to pass data between 2 sibling components, then the event bus can also be used.
Check out this blog which would help you understand better.
supppose for 2 components : CompA & CompB having same parent and main.js for setting up main vue app. For passing data from CompA to CompB without involving parent component you can do the following.
in main.js file, declare a separate global Vue instance, that will be event bus.
export const bus = new Vue();
In CompA, where the event is generated : you have to emit the event to bus.
methods: {
somethingHappened (){
bus.$emit('changedSomething', 'new data');
}
}
Now the task is to listen the emitted event, so, in CompB, you can listen like.
created (){
bus.$on('changedSomething', (newData) => {
console.log(newData);
})
}
Advantages:
Less & Clean code.
Parent should not involve in passing down data from 1 child comp to another ( as the number of children grows, it will become hard to maintain )
Follows pub-sub approach.

I've found a way to pass parent data to component scope in Vue, i think it's a little a bit of a hack but maybe this will help you.
1) Reference data in Vue Instance as an external object (data : dataObj)
2) Then in the data return function in the child component just return parentScope = dataObj and voila. Now you cann do things like {{ parentScope.prop }} and will work like a charm.
Good Luck!

I access main properties using $root.
Vue.component("example", {
template: `<div>$root.message</div>`
});
...
<example></example>

A global JS variable (object) can be used to pass data between components. Example: Passing data from Ammlogin.vue to Options.vue. In Ammlogin.vue rspData is set to the response from the server. In Options.vue the response from the server is made available via rspData.
index.html:
<script>
var rspData; // global - transfer data between components
</script>
Ammlogin.vue:
....
export default {
data: function() {return vueData},
methods: {
login: function(event){
event.preventDefault(); // otherwise the page is submitted...
vueData.errortxt = "";
axios.post('http://vueamm...../actions.php', { action: this.$data.action, user: this.$data.user, password: this.$data.password})
.then(function (response) {
vueData.user = '';
vueData.password = '';
// activate v-link via JS click...
// JSON.parse is not needed because it is already an object
if (response.data.result === "ok") {
rspData = response.data; // set global rspData
document.getElementById("loginid").click();
} else {
vueData.errortxt = "Felaktig avändare eller lösenord!"
}
})
.catch(function (error) {
// Wu oh! Something went wrong
vueData.errortxt = error.message;
});
},
....
Options.vue:
<template>
<main-layout>
<p>Alternativ</p>
<p>Resultat: {{rspData.result}}</p>
<p>Meddelande: {{rspData.data}}</p>
<v-link href='/'>Logga ut</v-link>
</main-layout>
</template>
<script>
import MainLayout from '../layouts/Main.vue'
import VLink from '../components/VLink.vue'
var optData = { rspData: rspData}; // rspData is global
export default {
data: function() {return optData},
components: {
MainLayout,
VLink
}
}
</script>

Is it possible to change properties in Ember routes?

What is the correct way to set properties on an Ember route? I have a title message that I would like to be displayed on page load and then I would like to change that title as the user interacts with the page.
import Ember from 'ember';
export default Ember.Route.extend({
title: "Welcome!",
model(thing1) {
return Ember.RSVP.hash({
thing1: this.store.findRecord('thing1', thing1.thing_id),
thing2: this.store.findAll('thing2'),
thing3: this.store.findAll('thing3')
});
},
actions: {
changeTitle() {
this.set("title", "I changed!")
}
}
});
In my template I load another component and pass in the value for title
{{title-tile title=title}}
And in my component title, I print out (theoretically) the title:
{{title}}
I have also tried removing the intermediary step and just printing out the title directly but that doesn't work.
In the console I have no errors, and I am otherwise able to print out the model data from the RSVP hash. There is no (obvious) documentation on this. All documentation focuses on printing out model properties.
What am I missing?
Edit
It appears to me that routes are just meant to handle models and that components are supposed to take care of everything else.
I've actually tried explicitly calling the title to be set on route load and it still doesn't work.
...
init() {
title: "Welcome!"
}
...

You could use a computed property in hash passed to template:
export default Ember.Route.extend({
title: 'Welcome!',
model(thing1) {
return Ember.RSVP.hash({
// ... omitted for brevity
title: Ember.computed(() => this.get('title')) // computed property
});
},
actions: {
changeTitle() {
this.set("title", "I changed!")
this.refresh(); // it is required to refresh model
}
}
});
Working demo.
Full code behind demo.