Vue-multiselect inconsistent reactive options - vue.js

So I'm building an application using Laravel Spark, and therefore taking the opportunity to learn some Vue.js while I'm at it.
It's taken longer for me to get my head around it than I would have liked but I have nearly got Vue-multiselect working for a group of options, the selected options of which are retrieved via a get request and then updated.
The way in which I've got this far may well be far from the best, so bear with me, but it only seems to load the selected options ~60% of the time. To be clear - there are never any warnings/errors logged in the console, and if I check the network tab the requests to get the Tutor's instruments are always successfully returning the same result...
I've declared a global array ready:
var vm = new Vue({
data: {
tutorinstruments: []
}
});
My main component then makes the request and updates the variable:
getTutor() {
this.$http.get('/get/tutor')
.then(response => {
this.tutor = response.data;
this.updateTutor();
});
},
updateTutor() {
this.updateTutorProfileForm.profile = this.tutor.profile;
vm.tutorinstruments = this.tutor.instruments;
},
My custom multiselect from Vue-multiselect then fetches all available instruments and updates the available instruments, and those that are selected:
getInstruments() {
this.$http.get('/get/instruments')
.then(response => {
this.instruments = response.data;
this.updateInstruments();
});
},
updateInstruments() {
this.options = this.instruments;
this.selected = vm.tutorinstruments;
},
The available options are always there.
Here's a YouTube link to how it looks if you refresh the page over and over
I'm open to any suggestions and welcome some help please!

Your global array var vm = new Vue({...}) is a separate Vue instance, which lives outside your main Vue instance that handles the user interface.
This is the reason you are using both this and vm in your components. In your methods, this points to the Vue instance that handles the user interface, while vm points to your global array that you initialized outside the Vue instance.
Please check this guide page once more: https://v2.vuejs.org/v2/guide/instance.html
If you look at the lifecycle diagram that initializes all the Vue features, you will notice that it mentions Vue instance in a lot of places. These features (reactivity, data binding, etc.) are designed to operate within a Vue instance, and not across multiple instances. It may work once in a while when the timing is right, but not guaranteed to work.
To resolve this issue, you can redesign your app to have a single Vue instance to handle the user interface and also data.
Ideally I would expect your tutorinstruments to be loaded in a code that initializes your app (using mounted hook in the root component), and get stored in a Vuex state. Once you have the data in your Vuex state, it can be accessed by all the components.
Vuex ref: https://vuex.vuejs.org/en/intro.html
Hope it helps! I understand I haven't given you a direct solution to your question. Maybe we can wait for a more direct answer if you are not able to restructure your app into a single Vue instance.

What Mani wrote is 100% correct, the reason I'm going to chime in is because I just got done building a very large scale project with PHP and Vue and I feel like I'm in a good position to give you some advice / things I learned in the process of building out a PHP (server side) website but adding in Vue (client side) to the mix for the front end templating.
This may be a bit larger than the scope of your multiselect question, but I'll give you a solid start on that as well.
First you need to decide which one of them is going to be doing the routing (when users come to a page who is handling the traffic) in your web app because that will determine the way you want to go about using Vue. Let's say for the sake of discussion you decide to authenticate (if you have logins) with PHP but your going to handle the routing with Vue on the front end. In this instance your going to want to for sure have one main Vue instance and more or less set up something similar to this example from Vue Router pretending that the HTML file is your PHP index.php in the web root, this should end up being the only .php file you need as far as templating goes and I had it handle all of the header meta and footer copyright stuff, in the body you basically just want one div with the ID app.
Then you just use the vue router and the routes to load in your vue components (one for each page or category of page works easily) for all your pages. Bonus points if you look up and figure using a dynamic component in your main app.vue to lazy load in the page component based on the route so your bundle stays small.
*hint you also need a polyfill with babel to do this
template
<Component :is="dynamicComponent"/>
script
components: {
Account: () => import('./Account/Account.vue'),
FourOhFour: () => import('../FourOhFour.vue')
},
computed: {
dynamicComponent() {
return this.$route.name;
}
},
Now that we are here we can deal with your multiselect issue (this also basically will help you to understand an easy way to load any component for Vue you find online into your site). In one of your page components you load when someone visits a route lets say /tutor (also I went and passed my authentication information from PHP into my routes by localizing it then using props, meta fields, and router guards, its all in that documention so I'll leave that to you if you want to explore) on tutor.vue we will call that your page component is where you want to call in multiselect. Also at this point we are still connected to our main Vue instance so if you want to reference it or your router from tutor.vue you can just use the Vue API for almost anything subbing out Vue or vm for this. But the neat thing is in your main JS file / modules you add to it outside Vue you can still use the API to reference your main Vue instance with Vue after you have loaded the main instance and do whatever you want just like you were inside a component more or less.
This is the way I would handle adding in external components from this point, wrapping them in another component you control and making them a child of your page component. Here is a very simple example with multiselect pretend the parent is tutor.vue.
Also I have a global event bus running, thought you might like the idea
https://alligator.io/vuejs/global-event-bus/
tutor.vue
<template>
<div
id="user-profile"
class="account-content container m-top m-bottom"
>
<select-input
:saved-value="musicPreviouslySelected"
:options="musicTypeOptions"
:placeholder="'Choose an your music thing...'"
#selected="musicThingChanged($event)"
/>
</div>
</template>
<script>
import SelectInput from './SelectInput';
import EventBus from './lib/eventBus';
export default {
components: {
SelectInput
},
data() {
return {
profileLoading: true,
isFullPage: false,
isModalActive: false,
slackId: null,
isActive: false,
isAdmin: false,
rep: {
id: null,
status: '',
started: '',
email: '',
first_name: '',
},
musicTypeOptions: []
};
},
created() {
if (org.admin) {
this.isAdmin = true;
}
this.rep.id = parseInt(this.$route.params.id);
this.fetchData();
},
mounted() {
EventBus.$on('profile-changed', () => {
// Do something because something happened somewhere else client side.
});
},
methods: {
fetchData() {
// use axios or whatever to fetch some data from the server and PHP to
// load into the page component so say we are getting the musicTypeOptions
// which will be in our selectbox.
},
musicThingChanged(event) {
// We have our new selection "event" from multiselect so do something
}
}
};
</script>
this is our child Multiselect wrapper SelectInput.vue
<template>
<multiselect
v-model="value"
:options="options"
:placeholder="placeholder"
label="label"
track-by="value"
#input="inputChanged" />
</template>
<script>
import Multiselect from 'vue-multiselect';
export default {
components: { Multiselect },
props: {
options: {
type: [Array],
default() {
return [];
}
},
savedValue: {
type: [Array],
default() {
return [];
}
},
placeholder: {
type: [String],
default: 'Select Option...'
}
},
data() {
return {
value: null
};
},
mounted() {
this.value = this.savedValue;
},
methods: {
inputChanged(selected) {
this.$emit('selected', selected.value);
}
}
};
</script>
<style scoped>
#import '../../../../../node_modules/vue-multiselect/dist/vue-multiselect.min.css';
</style>
Now you can insure you are manging the lifecycle of your page and what data you have when, you can wait until you get musicTypeOptions before it will be passed to SelectInput component which will in turn set up Multiselect or any other component and then handle passing the data back via this.$emit('hihiwhatever') which gets picked up by #hihiwhatever on the component in the template which calls back to a function and now you are on your way to do whatever with the new selection and pass different data to SelectInput and MultiSelect will stay in sync always.
Now for my last advice, from experience. Resist the temptation because you read about it 650 times a day and it seems like the right thing to do and use Vuex in a setup like this. You have PHP and a database already, use it just like Vuex would be used if you were making is in Node.js, which you are not you have a perfectly awesome PHP server side storage, trying to manage data in Vuex on the front end, while also having data managed by PHP and database server side is going to end in disaster as soon as you start having multiple users logged in messing with the Vuex data, which came from PHP server side you will not be able to keep a single point of truth. If you don't have a server side DB yes Vuex it up, but save yourself a headache and wait to try it until you are using Node.js 100%.
If you want to manage some data client side longer than the lifecycle of a page view use something like https://github.com/gruns/ImmortalDB it has served me very well.
Sorry this turned into a blog post haha, but I hope it helps someone save themselves a few weeks.

Related

best practice to change language dependent content coming from APIs

Background:
I have an SPA (Vuejs) and I implemented the localization both on frontend and backend side. The content is updated successfully without reloading the page when I change the language.
Problem:
But some contents (like product description in the selected language) are coming from an API which is not updated automatically when I change the language. If I refresh the page or call the API again, it works.
Question:
What is the best practice to change language dependent content coming from APIs without page refresh and calling manually all the APIs.
Thanks!
I believe there are many ways of doing what you want to do.
For instance. We have models that have some fields that can be localised, but we only support three languages and the fields are relatively short.
In that scenario, we just have the backend rest api return all localised versions of the string, e.g.:
GET /products could return:
[{
sku: '1',
name: {
en: 'Product name',
nl: 'Productnaam',
fr: 'Nom du produit'
}
}]
which we then just show in VueJs based on the route parameter... {{product.name[$route.params.locale] || product.name[en]}} (we have a composable method for this in stead, but you get the idea.
However, for some endpoints you might not always want to return all the localised versions of the server, just because it's too large (e.g. blogposts that you post in multiple languages while you support 5 languages might just generate a payload that you don't want to...)
In such scenario's, you can just watch for changes on your locale in vuejs, and fetch the localised version.
A third option, which I don't like myself, is have the "language switch" basically reload the entire page...
Either way - there's many ways to do what you need, it all depends on your use case, and your personal preference.
When using the vue-i18n Plugin, instead of sending the localised Text from the backend you could just send variables like exampleText and have them translated in your vue code with {{$t(yourLangVar)}} and this.$t(yourLangVar)
I managed to do it, I don't know if it is a best practice, but it is a working solution and can be useful for others:
App.vue:
I have a LocaleChanger component which emits localChanged on every language change.
the views are loaded into router-view so I added rerenderKey to its key. And when it is changed, everything will be rerendered in the current view(including the APIs of the corresponding components).
And since all of my APIs are called in it, They will be called again.
<template>
<LocaleChanger #localChanged="forceRerender"/>
<div id="nav">
<router-link :to="{ name: 'Home', params: {'lang':$i18n.locale}}">{{$t('pages.home')}}</router-link> |
</div>
<router-view :key="rerenderKey"></router-view>
</template>
<script>
data () {
return {
rerenderKey: 0
};
},
methods: {
async forceRerender(){
await this.$router.push({name: this.$route.name, params: { ...this.$route.params, lang: this.$i18n.locale }})
this.rerenderKey += 1;
},
}
</script>
And since my API-s need the Accept-language header, I added it in main.js to the axios.interceptors.request
axios.interceptors.request.use(
function (config) {
config.headers['Accept-Language'] = store.state.locale;
return config;
},
function (error) {
return Promise.reject(error);
}
);

Access higher level component (parent) properties from subsubcomponents (children of children)

I am working on something which requires access to a property injected at the top level of a VueJS application. I can access the property by using:
this.$parent.$attrs.propertyname
This works nicely however, I am now wanting to be able to access the same item from a further subcomponent which works the same as above with an additional $parent call. Is there a way I can call this item at the top level in another way?
I have looked at $root and tested using Vue $vm console calls in the browser but doesnt work so far. I suspect theres a really easy way of doing this but I can't find it at the moment.
I have tried:
adding a return method from top level and calling it
$root
setting a prototype outside the vue application at the top level: Vue.prototype.$varname = '' and then attempting to assign on created() to this.$varname = this.mypropertyname
I suspect I am close somewhere or there is something I have missed.
I did plenty of fiddling and I have my answer.
So basically, my application passes data into the app from Laravel at the tag level. I have an overall template file for the app which is where I now set the data with a setter to root.
I will explain with some code:
Laravel:
<v-app token="abcdefg">
<template></template>
</v-app>
Thats the declaration of data passed into the app
On template.vue:
<script>
export default {
name: "template",
created() {
this.$root.setToken(this.$parent.$attrs.token);
}
}
</script>
We access the data and use the setter placed on app.js (root) to assign the data to an accessible $root location
app.js code:
const app = new Vue({
data() {
return {token: ''}
},
moment,vuetify,
router, store,
el: '#app',
methods: {
setToken(token)
{
this.token = token;
},
getToken()
{
return this.token;
}
}
});
A getter and setter available for the whole app to access. I may restrict access to the setter function later on but for now I am happy it works. Suggestions on restricting this will be nice.
Its now accessible via: this.$root.getToken()

Recommended way of waiting on an Apollo query before rendering the next page?

When using the Apollo module in a Nuxt app, the default behavior when changing routes is to render the new page immediately, before data has been fetched via Apollo.
This results in some pretty janky rendering experiences where the page does a partial render and very soon after completes rendering with data from the server, making everything on the page shift due to the changing size of components that now have data. This looks pretty bad because the data actually comes back fairly quickly, so it would be fine to wait for the data to return before rendering the new route.
What's the recommended way of waiting on the Apollo queries on a page (and its subcomponents) to complete before rendering the page?
(There's a related question that's not specific to Nuxt, but I'm not sure how to translate the recommendation to a Nuxt app.)
I'd love to see a code example of using beforeRouteEnter to fetch data via Apollo and only entering the route once the data is fetched.
Haven't used this module before, but it should be like any other async action you want to perform before page rendering in Nuxt.
It only depends if you want to pre-fill the store:
https://github.com/nuxt-community/apollo-module#nuxtserverinit
https://nuxtjs.org/guide/vuex-store/#the-nuxtserverinit-action
or only one page:
https://github.com/nuxt-community/apollo-module#asyncdatafetch-method-of-page-component
https://nuxtjs.org/guide/async-data
You can use async/await or promises if you have more than one request before page should be rendered.
When async actions are finished, Nuxt starts rendering the page. This works for SSR and if you navigate to pages on the client (nuxtServerInit will only fire once when real request is made, not when navigating on client side).
Side note: beforeRouteEnter is usually used, to validate params and check if the route is allowed.
did you try disabling the prefetch?
prefetch: false
The best approach is to use the loading attribute:
<template>
<div v-if="!this.$apollo.loading">
Your product: {{product}}
</div>
</template>
<script>
export default {
name: "Product",
apollo: {
product: {
query: productQuery,
variables() {
return {
productId: this.productId
}
}
}
}
}
</script>
I'm unfamiliar with Apollo, but I think this is what you are looking for:
// Router.js
beforeRouteEnter(to, from, next)
{
executeSomeApolloPromise().then((data) => {
// The promise has now been complete; continue to the component.
next((vm) => {
// You have access here to the component instance via `vm`.
// Note that `beforeRouteEnter` is the only guard that has this.
vm.someApolloData = data;
});
});
}
See https://router.vuejs.org/guide/advanced/navigation-guards.html#per-route-guard

Vue router not navigating

I'm having problems getting VueRouter to navigate.
Within my app some pages work fine, and with identical code, other pages the routing doesn't work / page doesn't update navigate.
Are there some gotchas with the router? Like you cannot call the router from within components or... ?
named route in my app
export default new VueRouter({
routes: [
{
path: '/grams/one/:cname',
component: GramsOne,
name: "gramsOne"
},
...
Then inside a component on a page:
<q-btn v-for='(rel, key) in gram.relatedItems' :key='key'
color='secondary'
#click="goGram(rel)"
>
{{rel.cn}}
</q-btn>
// later in the script:
methods: {
goGram(gram) {
let newRoute = {
name: 'gramsOne',
params: {cname: gram.cname}
}
console.log('goGram', newRoute)
this.$router.push(newRoute)
}
},
Elsewhere on the same page, simple routes work.
The URL address will get updated in the browser.
I see the right console log with route info
But the page/content will not change.
Once the URL bar has been updated, I can hit ctrl-R and the new page will get loaded. So the destination route is working fine.
From other pages in the same app I can use the same route to target new destination and loads fine.
This is also loading with the same URL and just a query param different that is causing the problem.
/app/items/foo
/app/items/bar
where bar is a type of some property /app/items/:foo
I have tried various combinations of named routes, routes using etc, and can't really see a pattern.
"vue": "~2.5.0",
"vue-resource": "^1.3.4",
"vue-router": "^2.7.0"
Thanks any hints!
The Component in this case is the same, so vue will reuse the instance.
The this.$route in the component will change but created(), beforeMounted() and mounted() hooks won't be callled.
Which is probably where you use the this.$route.params.cname
To force vue to create a new component instance you can set a unique key on the like <router-view :key="$route.fullPath">
Another options is to react to changes in the $route with a watcher:
watch: {
"$route.params.cname": {
handler(cname) {
// do stuff
},
immediate: true
}
}
Router can be called within a component just fine. In fact, you usually call router from the component.
From the code snippets provided, at one point in the code you use cn, then at other point you use cname. That might be the problem why it never quite work for you.
I create a codesandbox to recreate your scenario, and besides that minor naming mentioned above, things seem to work just fine.

Load AJAX in Framework7, vue

I'm very new to Framework7, and want to build a fairly simple mobile app -- a list of places, detail pages of those places (where some murals are displayed), and a map and about page. My current plan is to publish it via PhoneGap Build, since that seems like a fast and easy way to deploy.
I created my app using the phonegap-framework7-vue template. Perhaps overkill for such a simple app, but seems better than building it from scratch.
I want to load a list of places via AJAX (eventually via sqlite), and can't figure out how/when to do this, and how to access the main app. My Murals.vue file has the template and the following script, but doesn't load because app.request is undefined. I've tried "framework7", "Framework7", and moving it outside of the mounted() call, but feel like I'm just guessing. Any suggested? Thanks!
<script>
import F7List from "framework7-vue/src/components/list";
let dataURL = 'https://jsonplaceholder.typicode.com/posts'; // returns some json
export default {
name: 'Murals',
components: {F7List},
mounted() { // when the Vue app is booted up, this is run automatically.
app.request.get(dataURL, function (data) {
console.log(data);
});
},
data () {
return {
title: 'Murals'
};
}
};
</script>
You're code is almost right !
To access to F7 app instance with vue, you have to use this.$f7.request rather the app.request