We have a nuxt.js application which retrieves data from strapi. this works for all the other pages that we've created, but when we try to retrieve data for the <Footer /> it appears that the code is not executing.
This is the code that we use for retrieving on the index page:
export default {
async asyncData({ $strapi }) {
return {
homepage: await $strapi.find("homepage"),
};
},
}
All we change from page to page is the variable name and the value its finding.
This works on 10 - 12 pages.
On main pages we are able to retrieve the data of the footer with this code:
export default {
async asyncData({ $strapi }) {
return {
footer: await $strapi.find("footer")
};
},
}
However when we put this code in our footer component it doesn't appear to execute, as no variable was shown in the view explorer, and if we try an render anything form the {{footer}} then we get an error saying we've referenced something that doesn't exist.
Is there any reason why this code isn't executing in the footer component?
The asyncData hook can only be used on page components. The official documentation explains how you can work around this issue:
asyncData is only available for pages and you don't have access to this inside the hook.
Use the new fetch hook that is available in Nuxt 2.12 and later versions.
Make the API call in the mounted hook and set data properties when loaded. Downside: Won't work for server side rendering.
Make the API call in the asyncData method of the page component and pass the data as props to the sub components. Server rendering will work fine. Downside: the asyncData of the page might be less readable because it's loading the data for other components.
Related
I have a SPA with dynamic routing. On page loading I'm making a fetch request for products. Then set it to the vuex store and use it. I also have a dynamic routing for product pages '/product/:id'
The problem is if I reload a product page say site.com/product/2 then nothing renders. I think this happens because at that moment store is empty and there're nothing to render.
How can I fix that?
In ProductPage component I tried using navigation guard with no success. Code below returns error: Cannot read properties of undefined (reading 'products').
Fetch request is made on mounting in TheMain component (when I reload ProductPage fetch request is made as well).
ProductPage component:
computed: {
...mapState(["products"]), // get products array from store
},
beforeRouteEnter(to, from, next) {
if (this.products) { // check if products array exists and then load data
next(true);
}
},
I think you need to make beforeRouteEnter async and add await for the store action which does the fetch or axios call.
async beforeRouteEnter(to, from, next) {
if (this.products) {
// check if products array exists and then load data
await dispatch(‘action_to_get_data’);
/// Wait to go to next for dispatch to finish.
next(true);
}
}
In your action you also need to use async / await.
What also might help is a v-if on the ProductPage component, so the components only loads when the products are loaded in the store.
For vue3 you may also take a look at the experimental Suspense component. But I don’t know if this works with beforeRouteEnter.
Hope this helps.
I have a Vue app which does a little localStorage and server check on app load, to determine where to initially route the user.
This is in the App's main entry component, in the created() hook
My problem is that the default / route's Component visibly loads first, then the server call and everything happens which causes the user the route to their correct location
How can I delay the rendering of the initial component until my app's main component created() method completes, and then purposely navigates the user to the correct route?
I had this problem before and I firmly believe that you must have the initial files for your routes and your router configuration.
In the configuration, you could handle the permission and router before each route and with next() . In the router file, you can set your params and check them in the index.js file(router configuration)
you could also use your localStorage data in Router.beforeeach
EDIT: I just saw you used the created method... like mentioned below use beforeRouteEnter instead with the next() parameter it provides
First of all I wouldn't recommend using a delay but instead a variable that keeps track if the API call is done or not. You can achieve this using the mounted method:
data() {
return {
loaded: false,
}
}
async mounted() {
await yourAPICALL()
if (checkIfTokenIsOkay) {
return this.loaded = true;
}
// do something here when token is false
}
Now in your html only show it when loaded it true:
<div v-if="loaded">
// html
</div>
An better approuch is using the beforeRouteEnter method which allows you to not even load the page instead of not showing it: https://router.vuejs.org/guide/advanced/navigation-guards.html
I am trialling a project in Nuxt. Liking it so far except I am a little confused as to how to load data from an external async service so that it is available in Vuex from the very first route.
I have tried adding middleware on the default layout to dispatch the store action but I do not see the service being called straight away. Only when I navigate deeper into the routes do I see the action dispatched.
I did something similar in a standard Vue project and added the created method to the App.vue.
Is there a similar way in Nuxt?
What you need is called a fetch.
The fetch method, if set, is called every time before loading the component (only for page components). It will be called server-side once (on the first request to the Nuxt app) and client-side when navigating to further routes.
Warning: You don't have access of the component instance through this inside fetch because it is called before initiating the component.
async fetch({ store }) {
await store.dispatch('your-action')
}
If you need parameter:
async fetch({ store, params }) {
await store.dispatch('your-action', params.id)
}
I gave an example of id. The name of the parameter depends on the name of your page.
_id => params.id
_slug => parmas.slug
...
I have a homepage with <router-link> tags to views. It is a simple master/detail relationship where the Homepage is a catalogue of products and the Product detail page/view shows information on each item.
When I first launch the website and click on an item on the Homepage view (e.g. URL: http://localhost:8080/100-sql-server-2019-licence), the Product view gets loaded and the product detail loads fine.
If I then press the back button in the browser to return to the Homepage and then click on a different Product (e.g. URL: http://localhost:8080/101-oracle-12c-licence), the URL in the browser address bar changes but I get the previous product's information. Its lightning quick and no new network calls are done which means its just showing a cached page of the previous product. If I then hit the refresh button while on that page, the network call is made and the correct product information is displayed.
I did a search online but couldn't find this problem described on the search results. Could anyone point me in the right direction of how to cause a refresh/re-render of a route when the route changes?
What is happening
vue-router will cache your components by default.
So when you navigate to the second product (that probably renders the same component as the first product), the component will not be instantiated again for performance reasons.
From the vue-router documentation:
For example, for a route with dynamic params /foo/:id, when we
navigate between /foo/1 and /foo/2, the same Foo component instance
will be reused.
The easy (but dirty) fix
The easy -but hacky and not recommended - way to solve this is to give your <router-view /> a key property, e.g.:
<router-view :key="$route.fullPath" />
This will force vue-router to re-instantiate the view component every time the url changes.
However you will loose all performance benefits you would normally get from the caching.
Clean fix: properly handling route changes
The clean way to solve this problem is to react to the route-change in your component (mostly this boils down to moving ajax calls from mounted into a $route watcher), e.g.:
<script>
export default {
data() {
return {
productDetails: null,
loading: false
};
},
watch: {
'$route': {
// with immediate handler gets called on first mount aswell
immediate: true,
// handler will be called every time the route changes.
// reset your local component state and fetch the new data you need here.
async handler(route) {
this.loading = true;
this.productDetails = null;
try {
// example for fetching your product data
const res = await fetch("http://give.me.product.data/" + encodeURIComponent(route.params.id));
this.productDetails = await res.json();
} finally {
this.loading = false;
}
}
}
}
};
</script>
Alternative: Navigation Guards
Alternatively you could also use vue-routers In-Component Navigation Guards to react to route changes:
<script>
export default {
async beforeRouteUpdate (to, from, next) {
// TODO: The route has changed.
// The old route is in `from`, the new route in `to`.
this.productData = await getProductDataFromSomewhere();
// route will not change before you haven't called `next()`
next();
}
};
</script>
The downside of the navigation guards is that you can only use them directly in the component that the route renders.
So you can't use navigation guards in components deeper within the hierarchy.
The upside is that the browser will not view your site before you call next(), which gives you time to load the data necessary before your route is displayed.
Some helpful ressources
Vue Router Navigation Guards Documentation
vue-router github issue
Similar Question about vue-router component reuse on stackoverflow
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