methods: {
showAlert() {
alert("alert");
}
},
created() {
setTimeout(this.showAlert(), 5000)
}
My codes are in here. I want to set time out in created area. But browser does not see setTimeout. it always runs when the page renders. Its not waiting. How to fix that problem?
run the method inside the setTimeout callback like :
created() {
setTimeout(()=>{
this.showAlert()
}, 5000)
}
Related
When I dispatch an action in App.vue component in mounted() lifecycle hook, it runs after other components load. I am using async/await in my action and mounted lifecycle hook.
App.vue file
methods: {
...mapActions({
setUsers: "setUsers",
}),
},
async mounted() {
try {
await this.setUsers();
} catch (error) {
if (error) {
console.log(error);
}
}
},
action.js file:
async setUsers(context) {
try {
const response = await axios.get('/get-users');
console.log('setting users');
if (response.data.success) {
context.commit('setUsers', {
data: response.data.data,
});
}
} catch (error) {
if (error) {
throw error;
}
}
},
In Users list component, I need to get users from vuex. So I am using mapGetters to get Users list.
...mapGetters({
getUsers: "getUsers",
}),
mounted() {
console.log(this.getUsers);
},
But the problem is "setting users" console log in running after console logging the this.getUsers.
In Users list component, I can use getUsers in the template but when I try to console log this.getUsers it gives nothing.
How can I run app.vue file before running any other components?
You are using async await correctly in your components. It's important to understand that async await does not hold off the execution of your component, and your component will still render and go through the different lifecycle hooks such as mounted.
What async await does is hold off the execution of the current context, if you're using it inside a function, the code after the await will happen after the promise resolves, and in your case you're using it in the created lifecycle hook, which means that the code inside the mounted lifecycle hook which is a function, will get resolved after the await.
So what you want to do, is to make sure you render a component only when data is received.
Here's how to do it:
If the component is a child component of the parent, you can use v-if, then when the data comes set data to true, like this:
data() {
return {
hasData: false,
}
}
async mounted() {
const users = await fetchUsers()
this.hasData = true;
}
<SomeComponent v-if="hasData" />
If the component is not a child of the parent, you can use a watcher to let you know when the component has rendered. When using watch you can to be careful because it will happen every time a change happens.
A simple rule of thumb is to use watch with variables that don't change often, if the data you're getting is mostly read only you can use the data, if not you can add a property to Vuex such as loadingUsers.
Here's an example of how to do this:
data: {
return {
hasData: false,
}
},
computed: {
isLoading() {
return this.$store.state.app.users;
}
},
watch: {
isLoading(isLoading) {
if (!isLoading) {
this.hasData = true;
}
}
}
<SomeComponent v-if="hasData" />
if you're fetching a data from an API, then it is better to dispatch the action inside of created where the DOM is not yet rendered but you can still use "this" instead of mounted. Here is an example if you're working with Vuex modules:
created() {
this.fetchUsers();
},
methods: {
async fetchUsers() {
await this.$store.dispatch('user/setUsers');
},
},
computed: {
usersGetters() {
// getters here
},
},
Question: Do you expect to run await this.setUsers(); every time when the app is loaded (no matter which page/component is being shown)?
If so, then your App.vue is fine. And in your 'Users list component' it's also fine to use mapGetters to get the values (note it should be in computed). The problem is that you should 'wait' for the setUsers action to complete first, so that your getUsers in the component can have value.
A easy way to fix this is using Conditional Rendering and only renders component when getUsers is defined. Possibly you can add a v-if to your parent component of 'Users list component' and only loads it when v-if="getUsers" is true. Then your mounted logic would also work fine (as the data is already there).
is it possible to pass function inside "done" callback in vue animation
enter: function(e, done) {
element.animate({
// ...
}, duration, done)
}
in a way that next "afterEnter" hook will be called ? If I do it jQuery way:
enter: function(e, done) {
element.animate({
// ...
}, duration, function() {
// do something
})
}
the "afterEnter" javascript hook is not called anymore
Answering own stupid question, it was pretty simple, just return it from callback. Documantation just messed me, there is "done" just called at the end of the hook.
https://v2.vuejs.org/v2/guide/transitions.html
enter: function(e, done) {
element.animate({
// ...
}, duration, function() {
// do something
return done()
})
}
I use beforeCreate and beforeDestroy hooks in order to add classes to body. In some cases I need to add classes, in some not.
So I have such code in each component which requires this functionality:
beforeCreate() {
document.body.classList.add('has-background')
},
beforeDestroy() {
document.body.classList.remove('has-background')
}
The problem is that if I navigate from one route to another, say from A component to B component, the beforeCreate of the B component executed first, and then beforeDestroy of the A component, which removes the has-background class.
How can I solve the issue?
Try using nextTick()
beforeCreate() {
this.$nextTick().then(() => document.body.classList.add('has-background'))
},
Edit:
I also suggest to use created() rather than beforeCreated(). But to achieve the best behavior, it is best to use mounted()
I have the same issue on my project and I have applied something like this.
methods: {
toggleBodyClass(addRemoveClass, className) {
const el = document.body;
if (addRemoveClass === 'addClass') {
el.classList.add(className);
} else {
el.classList.remove(className);
}
},
},
mounted() {
this.toggleBodyClass('addClass', 'mb-0');
},
destroyed() {
this.toggleBodyClass('removeClass', 'mb-0');
}
I would like to detect when page is refreshed or reloaded in vue.js. I have read the question from this post Do something before reload or close in vue.js. It's using window.onbeforeunload. But the problem for me, where do I put this window function ? Could we use another default method from vuejs for detecting the page that is refreshed ?
Thank you
You can use the created function to call another function. Example:
created() {
window.addEventListener('beforeunload', this.handler)
},
methods: {
handler: function handler(event) {
// Do Something
}
}
or
created() {
window.addEventListener('beforeunload', function(event) {
event.returnValue = 'Write something'
})
},
Check it : https://forum.vuejs.org/t/detect-browser-close/5001/8
I have registered 'beforeunload' event on created hook of the component used by routes of vue router.
I want to call this event handler in order to remove user on browser tab close or browser tab refresh or browser close.
On ComponentA
created (){
window.addEventListener('beforeunload', () => {
this.removeUser()
return null
})
}
Smilarly on ComponentB
created (){
window.addEventListener('beforeunload', () => {
this.removeUser()
return null
})
}
And my router.js
{
path: '/staff/call/:session_key',
name: 'Staff Call',
component: ComponentA,
meta: {auth: true}
},
{
path: '/consumer/call/:session_key',
name: 'Consumer Call',
component: ComponentB
},
Here 'beforeunload' event handler is triggered randomly. That is sometimes it get triggered and sometimes not. I count find any pattern when it is triggered and when it is not.
What am I missing here?
Edit
I'd guess the most likely culprit then is exactly what #PatrickSteele said. From MDN:
Note: To combat unwanted pop-ups, some browsers don't display prompts
created in beforeunload event handlers unless the page has been
interacted with; some don't display them at all. For a list of
specific browsers, see the Browser_compatibility section.
I'd say it's likely you're seeing inconsistent behavior because you are sometimes not interacting with the page.
This may be a syntax error. created should be a method
created () {
window.addEventListener('beforeunload', this.removeUser)
},
methods: {
removeUser () {
//remove user here
}
}
A fiddle working: https://jsfiddle.net/e6m6t4kd/3/
It's work for me. while do something before reload or close in
vue.js
created() {
window.onbeforeunload = function(){
return "handle your events or msgs here";
}
}
I had to do some fiddling on the above examples, I believe this is the most robust solution:
let app1 = new Vue({
delimiters: ['[[', ']]'],
el: '#app',
data: {
dirty_form: true,
},
created () {
console.log('created')
window.addEventListener('beforeunload', this.confirm_leaving)
},
methods: {
confirm_leaving (evt) {
if (this.dirty_form) {
const unsaved_changes_warning = "You have unsaved changes. Are you sure you wish to leave?";
evt.returnValue = unsaved_changes_warning;
return unsaved_changes_warning;
};
};
},
});
If you want detect page refresh/change in Vue whenever you press F5 or Ctrl + R, You may need to use Navigation Timing API.
The PerformanceNavigation.type, will tell you how the page was accessed.
created() {
// does the browser support the Navigation Timing API?
if (window.performance) {
console.info("window.performance is supported");
}
// do something based on the navigation type...
if(performance.navigation.type === 1) {
console.info("TYPE_RELOAD");
this.removeUser();
}
}
Not sure why none of the above were fully working for me in vue 3 composition api. Abdullah's answer partially works but he left out how to remove the listener.
setup() {
const doSomething = (e) => {
// do stuff here
return true
}
onBeforeMount(() => {
window.onbeforeunload = handleLeaveWithoutSaving
})
onUnmounted(() => {
window.onbeforeunload = null
})
}