I have an App.vue component where I want to load the currently logged in user. I also want to redirect the user when he\she tries to go the login route and the currently logged in user is already saved in context (he's already signed in).
// inside App.vue component
created() {
AuthService.getCurrentUser().then((user) => {
this.user = user;
});
}
I have a check in the created method of the login component for whether the currentUser is setted, but then when the user tries to go to the login page it might be possible that the the request for the current user is not finished.
My question is:
How do I wait for the data to load before the App.vue component loads?
I saw something like this:
waitForData: true,
data(transition) {
return AuthService.getCurrentUser().then(currentUser => {
transition.next({ currentUser });
});
}
which doesn't actually wait for the data to be loaded and the component loads anyway.
Edit: I'm aware of beforeRouteEnter but this is App.vue component which is a parent component of all components and not a route specific component.
I ran into a very similar problem and solved by adding a v-if on the element that wrapped the child component that depends on the loaded data. And then of course have an data property to control that v-if. If you don't have a wrapping element you can always use a template element to do the wrapping.
This is not the Vue way of doing things.
Use VUEX to store your currentUser object
Set up the Vuex getters in App.vue's computed section. Your template will be updated dynamically once the data is ready.
See the mapGetters section in this page. It works very well with the computed mechanism.
You can also use v-if in your relevant component, so that the component won't be created before your data is ready in VUEX.
If using vue-router, you can use the beforeRouteEnter guard to load data async, as described here: https://router.vuejs.org/en/advanced/data-fetching.html
One way I can think of is when the user is loaed in the App.vue component to check the current path and if it's \login to redirect.
Something like this:
created() {
AuthService.getCurrentUser()
.then(user => this.setCurrentUser(user))
.then(() => {
const { path } = this.$router.currentRoute;
if (path === '/login') {
this.$router.push('/');
}
});
Related
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 pretty new to vuejs and am building a vuejs project. One of the tasks I am stuck at is, that I want to call a function written in the javascript part of vuejs from the html part of vuejs without creating any buttons or textboxes. I want to call this function as soon as my app starts. How do I achieve this? When I use mounted (vue lifecycle hook), the page it redirects to keeps refreshing. would appreciate some leads on this.
For example, I have a code:
<template>
<h1>Hello World!</h1>
<!--I WANT TO CALL THE auth0login function here. How do I do that without creating a button/text field,etc -->
</template>
<script>
export default {
data: () => ({
return : {
clientID: process.env.example
}
}),
methods:{
auth0login(){
console.log('logging in via Auth0!');
Store.dispatch('login');
}
}
}
</script>
I want to call the auth0login function defined in the script part in the html part above in order to execute the functionalities of the auth0login function. I want to do this without creating any buttons in the html file and simply just execute the auth0login function when the app launches.
How do I do this?
You need to call auth0login() only when you're not already logged I guess.
I think the reason is after user already logged in, they go back to the initial page, and the function in mounted() hook run again. Thats why they keep get redirect to login page. This not happen when you insert the button, because the button require user to click at it.
To fix this, you need to define a vuex state to store whether user has logged in or not, and in mounted() hook, just called it when they not login yet.
So. Instead of
mounted: function() { console.log('logging in via Auth0!'); this.auth0login() } }
Add a check login state
mounted() {
if(!this.$store.state.userLoggin) // here i define userLoggin and vuex state, you should update it to true whenever user successfully login
{ console.log('logging in via Auth0!'); this.auth0login() //only call it when user not loggin
}
}
And remember to update your vuex state.userLoggin when user successfully login in the auth0login() function
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
I'm building a vue.js application. We'd like to have a popup come up when the user attempts to leave a specific page. The popup should say "Are you sure you want to leave the page?" I know I can implement something in the beforeRouteLeave hook of the component, but I'm wondering if there's a way to implement this in the beforeEach event of the router (i.e. not the component). The reason I'd like to use the router is because beforeEach in the router seems to respond to the user entering a different path in the browser url bar, whereas the beforeRouteLeave hook on the component does not. However, I don't have access to the popup in the router whereas I do in the component (the popup would just be part of the template).
So the question is: how can I bring up a popup in the router before the user actually leaves the page?
Thanks.
First you can assign a name for each of your routes objects in routes array inside your router or another field like requiredConfirmation or something like that, imagine that we have a routes like this :
routes : [
{
path : '/needconfirm',
component : NeedConfirmToLeaveCom,
name : 'needconfirm-route1'
},
{
path : '/neednotconfirm',
component : NeedNotConfirmToLeaveCom,
name : 'normal-route1'
},
]
then you can use router.beforeEach to set some conditions or some confirmations based on your Origin route and Destination route.
something like this :
router.beforeEach((to,from,next) => {
if(from.name.startsWith("needconfirm-")) {
if(window.confirm("Are you sure you want to leave the page?")) {
next();
}
}else next();
});
UPDATE * :
if you want to use some custom components for your popup, you can use vuex to store your component's logic and toggler and import that component in your App.Vue or other root/child components you wish. because you have access to your store management using $store right?
UPDATE ** :
and one other thing i want to mention, if you want to save some progress or state and because of that you want to get confirmation from user (progress will lost if they switch route), you should consider using Vuex to store your progress or state of your application and if you want more persisted solution you can use VuexPersisted store management which uses LocalStorage.
Vue router navigation guards document
Vuex Doc
You should use beforeunload event listener on the main component in that view.
MDN Reference
Depending on the browser, it will show the popup with default values populated.
This is how I use it in the created hook of the main component
window.addEventListener("beforeunload", (e) => {
e.preventDefault()
// chrome requires returnValue to be set
const message = "You have unsaved changes. Are you sure you wish to leave?"
e.returnValue = message
return message
})
Can I add something to beforeDestroy to prevent destroying the component? ?
Or is there any way to prevent destroying the component ?
my case is that when I change spa page by vue-route, I use watch route first, but I found that doesn't trigger because the component just destroy..
As belmin bedak commented you can use keep-alive
when you use keep-alive two more lifecycle hooks come into action, they are activated and deactivated hooks instead of destroyed
The purpose of keep-alive is to cache and to not destroy the component
you can use include and exclude atteibutes of the keep-alive element and mention the names of the components that shoulb be included to be cached and be excluded from caching. Here is documentation
in case you want to forecefully destroy the component even if its cached you can use vm.$destroy() here
Further you can console.log in all the lifecycle hooks and check which lifecycle hook is being called
You can use vue-route navigation-guards, so if you call next(false) inside the hook, navigation will be aborted.
router.afterEach((to, from) => {
if(your condition){
next(false) //this will abort route navigation
}
})
According to this source: https://router.vuejs.org/guide/advanced/navigation-guards.html
I suggest you to do something like this with your Vue router:
const router = new VueRouter({ }); // declare your router with params
router.beforeEach((to, from, next) => {
if(yourCondition){
next(false); // prevent user from navigating somewhere
} else {
return next(); // navigate to next "page" as usual
}
});
This will prevent destroying your Vue instance on your declared condition, and it will also prevent user from navigating to another page.
Although I would consider #Vamsi Krishna "keep-alive" answer to be the proper "VueJS way" to solve this issue, I was not willing to refactor part of my code for it.
I also couldn't use the Vue router navigation guard "as-is" because in the case of beforeRouterLeave, even though using next(false) prevented the route from continuing, the component in Vue was ALREADY destroyed. Any state I had that wasn't saved would be lost, which defeats the purpose of cancelling the route change.
This wasn't what I wanted, as I needed the state of the form/settings in the component to remain (the component reloaded itself and kept the same route).
So I came up with a strategy that still used a navigation guard, but also cached any form changes/settings I had in the component in-memory, eg. I add a beforeRouteLeave hook in the component:
beforeRouteLeave (to, from, next) {
if (!this.isFormDirty() || confirm('Discard changes made?')) {
_cachedComponentData = null // delete the cached data
next()
} else {
_cachedComponentData = this.componentData // store the cached data based on component data you are setting during use of the component
next(false)
}
}
Outside the Vue component, I initialize _cachedComponentData
<script>
let _cachedComponentData = null
module.exports = {
...component code here
}
<script>
Then in the created or mounted life cycle hooks, I can set the _cachedComponentData to "continue where the user left off" in the component:
...
if (_cachedComponentData) {
this.componentData = _cachedComponentData
}
...