VueJs Async Api Data best practice - vue.js

I am building a headless SPA SSR in NuxtJs, and I am wondering what best practices is for making sure that the application only loads if connection has been established to the remote API.
This is currently my index.vue component:
<template>
<div class="wrapper">
<div class="content">
<div class="title">
<h1>{{site.meta.title}}</h1>
</div>
</div>
</div>
</template>
<script>
import Meta from '../classes/api/General/Meta'
export default {
data () {
return {
meta: null
}
},
created () {
Meta.getMeta().then((response) => {
this.meta = response.data
})
}
}
</script>
This sometimes resolves in that site.meta.title is undefined because the site is loading before the api data has been initialised. And yes, site.meta.title is defined under the hood in the api. So. Next step I was thinking was using async like following script:
<script>
import Meta from '../classes/api/General/Meta'
export default {
data () {
return {
meta: null
}
},
async created () {
await Meta.getMeta().then((response) => {
this.meta = response.data
console.log(response.data.site.logo)
})
}
}
</script>
Though this doesn't help anyway.
But with v-if="meta" it does help. Though: now it seems that Axios is not rendering the content in the code (ssr) anymore.

console.log is not something that you can really trust 100% of the time for async debugging tbh.
console.log(JSON.parse(JSON.stringify())) can help a bit more but it's still have some drawbacks sometimes.
As for best practices, both beforeCreate and created do run on both sides (server + client) so it's fine to use those. You can also use asyncData and the new fetch (it's a Nuxt hook, not the actual fetch API).
Beware of using the async/await syntax properly tho (no need for then here):
async created() {
const response = await Meta.getMeta()
this.meta = response.data
console.log(this.meta)
}
Also, with proper async/await, this one will never happen actually
because the site is loading before the api data has been initialised
You can read a bit more about the Nuxt lifecycle here: https://nuxtjs.org/docs/2.x/concepts/nuxt-lifecycle
I'd recommend usually going the async fetch() way (non blocking, nice helpers), or async asyncData() if you need a blocking method. Middlewares can also be useful to make the whole process more flexible around your application.
You can get the whole explanation between the differences of fetch vs asyncData here: https://nuxtjs.org/blog/understanding-how-fetch-works-in-nuxt-2-12/
And if you want to have an example on how to use fetch in a real world scenario, you can read this one: https://nuxtjs.org/blog/build-dev-to-clone-with-nuxt-new-fetch/

So, It turns out that I got this the completely wrong way around.
In the newest nuxt versions, async fetch method is now included (build in).
With this, all rendering etc works fine and as expected.
My ended working code looks like this now:
<script>
export default {
async fetch () {
this.meta = await fetch(
'https://testurl.com/meta'
).then(res => res.json())
},
data () {
return {
meta: null
}
}
}
</script>
And the beauty with fetch, is that you can add listeners" like so:
<p v-if="$fetchState.pending">Fetching site</p>
<p v-else-if="$fetchState.error">Error happened</p>
<p>This content will be rendered server side even though waiting time</p>
I'm just posting this because my original question was a bit miss explained, and hope to help somebody else.
Edit:
I have marked kissu as answer (did see the post after i created this one), because it was explained so nice and well done!
Thanks :-)

Related

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

Page reload causes Vuex getter to return undefined

Using Vue.js (Vuetify for FE).
A page reload causes the getter in Vuex to fail with pulling required data from the store. The getter returns undefined. The code can be found on GitHub at: https://github.com/tineich/timmyskittys/tree/master/src
Please see the full details on this issue at timmyskittys.netlify.com/stage1. This page has complete info on the issue and instructions on how to view the issue.
Note, there is mention of www.timmyskittys.com in the issue description. This is the main site. timmyskittys.netlify.com is my test site. So, they are the same for all intents and purposes. But, my demo of this issue is at the Netlify site.
I read the complete issue in the website you mentioned. It's a generic case.
Say, for cat details page url: www.timmyskittys.com/stage2/:id.
Now in Per-Route Guard beforeEnter() you can set the cat-id in store. Then from your component call the api using the cat-id (read from getters)
I found the solution to my issue:
I had to move the call of the action which calls the mutation that loads the .json file (dbdata.json) into a computed() within App.vue. This was originally done in Stage1.vue.
Thanks all for responding.
I had the same issue and my "fix" if it can be called that was to make a timer, so to give the store time to get things right, like so:
<v-treeview
:items="items"
:load-children="setChildren"
/>
</template>
<script>
import { mapGetters } from 'vuex'
const pause = ms => new Promise(resolve => setTimeout(resolve, ms))
export default {
data () {
return {
children: []
}
},
computed: {
...mapGetters('app', ['services']),
items () {
return [{
id: 0,
name: 'Services',
children: this.children
}]
}
},
methods: {
async setChildren () {
await pause(1000)
this.children.push(...this.services)
}
}
}
</script>
Even though this is far from ideal, it works.

How to define a subscription based on route params?

I'm using RxJS using vue-rx and I have a route that needs to fetch a slightly different AJAX API request depending on the params.
I've been playing with all kinds of different approaches, but this is the one that +should have+ worked.
import Vue from 'vue'
import numeral from 'numeral'
import { Observable } from 'rxjs/Observable'
import 'rxjs/add/observable/interval'
import 'rxjs/add/operator/switchMap'
import 'rxjs/add/operator/map'
import axiosObservable from '../lib/axiosObservable'
export default {
name: 'Exchange',
props: ['exchange_name'],
methods: {
exchangeFetch (exchangeName) {
return Observable
.interval(3000)
.switchMap(axiosObservable.get(Vue.config.infoCoinUrl + '/exchanges/' + exchangeName + '/market-pairs'))
.map((response) => response.data)
}
},
mounted () {
alert(exchangeName)
this.$subscribeTo(
this.exchangeFetch(this.exchange_name),
(data) => {
this.market_pairs = data
})
},
data () {
return {
market_pairs: []
}
},
But what happens is that the alert gets executed only once during browsing (and the wrong AJAX call gets ran every time).
I'm a bit noobish in all of this (Vue & JS), I'm suspecting this might be a bug in the vue-rx framework - or at least a surprising behavior (for noobie me).
The thing that I love about vue-rx is how it integrates into vue.js lifecycles and removes the danger of leaking observables (which coupled with an AJAX call accounts to a ddos attack).
I'm looking for a solution that uses vue-rx API , or at least doesn't require me to stop the observables "manually".
UPDATE 1 seems like the issue has nothing to do with vue-rx, it's the mounted block that doesn't get executed on props change....
The exchanges are loaded like this and it generally works, there should be nothing wrong with this...
<router-link v-for="exchange in exchanges" v-bind:key="exchange.name" class="navbar-item" :to="{ name: 'exchange-show', params: { exchange_name: exchange.name }}">{{ exchange.name }}</router-link>

how to make a component to get async data and to render server side?

We know that only router component may request asyncData in a ssr environment. i have one main component(not router component), i need some async data to render server side. because it is not router component, so i can't use asyncData for server side rendering.
so i have used created hook for calling async api, but component hook is synchronous and don't wait for promise. what to do for getting async data on server side?
App.vue - Main Component
export default {
components: {
footer: Footer,
header: Header,
selector: selector
},
beforeMount() {
// need preload metadata here
},
created () {
// it return preload metadata as response.
return this.$store.dispatch('GET_PRELOAD_META_DATA');
}
}
Action.js
GET_PRELOAD_META_DATA: ({ commit }) => {
return axios.get("api/preload").then(({ data }) => {
commit('SET_PRELOAD_DATA', data);
});
},
As of Vue 2.6, there is a new SSR feature that may accomplish what you’re trying to do. ServerPrefetch is now a hook that can resolve promises to get async data and can interact with a global store.
Check out more in their documentation. https://ssr.vuejs.org/api/#serverprefetch
(I know this an old post, but I stumbled upon it while googling and thought I might be able to help someone else googling too)

Vue-multiselect inconsistent reactive options

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.