vue js component doesn't rerender on the same page - vue.js

I have a component
<template>somecode</template>
<script>
export default {
name: 'Card',
created() {
axios.get(apiObjUrl)
somecode
})
}
</script>
this my url:
http://127.0.0.1:8080/#/card/12
But I have a problem:
when I use router-link like this:
<router-link to="/card/155"> card 155</router-link>
my url changes: http://127.0.0.1:8080/#/card/155
but the created() method doesn't get fired.
so I don't make new xhr request to api
and data not changes
what do I do?

As an alternative you can setup a key attribute on your <router-view> like this:
<router-view :key="$route.fullPath"></router-view>
As <router-view> is a component itself and unique keys force replacement of component instead of reusing it. So you can make use of life cycle hooks.
See the fiddle

That's just because your component is already created. You may try using the lifecycle hook updated() instead of created().
export default {
name: 'Card',
updated() {
axios.get(apiObjUrl)
somecode
})
}
Note: This will only work if your DOM changes. If you just want to listen on url changes and update accordingly you better $watch your route like this.
export default {
name: 'Card',
created() {
axios.get(apiObjUrl)
somecode
}),
watch: {
'$route': function() {
// do your stuff here
}
}
}

Related

Vue watch page url changes

I'm trying to watch page url. I don't use Vue Router.
My final goal is to set page url as input value:
<template>
<div>
<input v-model="pageUrl">
</div>
</template>
<script>
export default {
data() {
return {
pageUrl: window.location.href,
link: ''
}
},
watch: {
pageUrl: function() {
this.link = window.location.href
}
}
}
</script>
The example above doesn't work somewhy.
I've also tried
watch: {
'window.location.href': function() {
this.link = window.location.href
}
},
Input value is being set only once on component render.
What can be wrong?
well, that is exactly the reason you want to use vue-router!
vue can only detect changes in reactive properties: https://v2.vuejs.org/v2/guide/reactivity.html
if you want to react to changes in the url, you have 2 ways:
https://developer.mozilla.org/en-US/docs/Web/API/Window/popstate_event or
https://developer.mozilla.org/en-US/docs/Web/API/Window/hashchange_event
i would rather use vue-router or a similar plugin.

Pass #EventListener to Component via Vuejs Router

Before I used vuejs-router, I've loaded component in app this way:
<my-component #done="doneForm"
#cancel="cancelForm"></my-component>
Well, I want to use vuejs-router to load my-component. So, how can I pass #done and #cancel to my-component via vuejs-router?
You need to define a route to which your my-component will be instantiated. This component will contain the done and cancel callbacks, so:
var router = new VueRouter({
routes: [
{ path: '/someRoute', component: SomeComponent }
]
]
SomeComponent would be something like:
<template>
<my-component #done="doneForm" #cancel="cancelForm"></my-component>
</template>
<script>
import MyComponent from '/some/path/components/MyComponent'
export default {
components: {
myComponent: MyComponent
},
methods: {
doneForm () {
console.log('Form Done')
},
cancelForm () {
console.log('Cancel Form')
}
}
}
</script>
As you've not shown any code and how you're calling your <my-component> but the whole point is that the <my-component> needs to be instantiated somewhere within another component that can have hold the cancelForm and doneForm methods. If you didn't want these callbacks then you could set a route up to go straight to that component.
Another option is to make thing stateful using Vuex. You could remove the callbacks from the component and when the form is done within <my-component> set something in the state that you can react to somewhere else in your app. You could also do the same with events and raise an event to listen for and do something.

How to pass data from one view to another with the vue-router

When using the vue-router with .vue files, there is no documented way to pass data from one view/component to another.
Let's take the following setup...
main.js:
import Vue from 'vue';
import VueRouter from 'vue-router';
Vue.use(VueRouter);
let routes = [
{
path: '/page1',
component: require('./views/Posts.vue')
},
{
path: '/page2',
component: require('./views/EditPost.vue')
}
];
let router = new VueRouter({
routes
});
new Vue({
el: '#main',
router
});
Posts.vue:
<template>
<div>
Posts.vue passing the ID to EditPost.vue: {{ postId }}
</div>
</template>
<script>
export default {
data() {
return {
allPostsHere: // Whatever...
}
}
}
</script>
EditPost.vue:
<template>
<div>
EditPost.vue received ID from Posts.vue: {{ receivedId }}
</div>
</template>
<script>
export default {
data() {
return {
receivedId: // This is where I need the ID from Posts.vue
}
}
}
</script>
Please note: It is not possible to receive the ID directly from the EditPost.vue, because it has to be selected from Posts.vue.
Question: How can I pass the ID from one view/component to the other?
A route can only be accessed via a URL and a URL has to be something user can type into the URL bar, therefore to pass a variable from one view component to another you have to use route params.
I assume you have a list of posts in Posts component and want to change page to edit a specific post in EditPost component.
The most basic setup would be to add a link in the post list to redirect to the edit page:
<div v-for="post in posts">
{{ post.title }}
<router-link :to="'/post/' + post.id + '/edit'">Edit</router-link>
</div>
Your routes would look like this:
[
{
path: '/posts',
component: require('./views/Posts.vue'),
},
{
path: '/post/:postId/edit',
component: require('./views/EditPost.vue'),
props: true,
},
]
The props configuration option is just to inform the Router to convert route params to component props. For more information see Passing props to route components.
Then in EditPost you'd accept the id and fetch the post from server.
export default {
props: ['postId'],
data() {
return {
post: null,
}
},
mounted() {
this.fetchPost();
},
methods: {
fetchPost() {
axios.get('/api/post/' + this.postId)
.then(response => this.post = response.data);
},
},
}
After the request has been completed, EditPost has its own copy which it can further process.
Note, that on every post edit and every time you enter the post list, you'll make a request to the server which in some cases may be unnecessary, because all needed information is already in the post list and doesn't change between requests. If you want to improve performance in such cases, I'd advise integrating Vuex into your app.
If you decide to do so, the components would look very similar, except instead of fetching the post to edit via an HTTP request, you'd retrieve it from the Vuex store. See Vuex documentation for more information.
if you don't want the params appear in the URL bar,you can use window.sessionStorage, window.localStorage or vuex.
Before you leave the view, set your parameters and get it after entering the new view.
You can use a prop on the <router-view :my-id="parentStoredId"></router-view> to pass down data present in the app.vue (main component). To change the parent data you need to emit a custom event comprising the value, from the childs (Posts.vue, EditPost.vue).
Another way is the Non Parent-Child Communication.
The way I prefer is Vuex. Even if it require you to learn the usage, it will repay back when the app grows.

Navigating vuejs SPA via routes that share component does not refresh component data as expected

I have a couple routes in my vuejs SPA that I have set up using vue-router:
/create/feedback
/edit/feedback/66a0660662674061b84e8ea2fface0e4
The component for each route is the same form with a bit of smarts to change form values based on the absence or present of the ID in the route (feedbackID, in my example).
I notice that when I click from the edit route to the create route, the data in my form does not clear.
Below is the gist of my route file
import FeedbackFormView from './components/FeedbackForm.vue'
// Routes
const routes = [
{
path: '/create/feedback',
component: FeedbackFormView,
name: 'FeedbackCreate',
meta: {
description: 'Create Feedback',
}
},
{
path: '/edit/feedback/:feedbackId',
component: FeedbackFormView,
name: 'FeedbackEdit',
meta: {
description: 'Edit Feedback Form'
},
props: true
}
]
export default routes
Below is the gist of my component
<template lang="html">
<div>
<form>
<input v-model="model.someProperty">
</form>
</div>
</template>
<script>
export default {
data() => ({model: {someProperty:''}}),
props: ['feedbackId'],
created() => {
if (!this.$props['feedbackId']) {
return;
}
// otherwise do ajax call and populate model
// ... details omitted
}
}
</script>
However, if I modify my component as follows, everything works as expected
<template lang="html">
<div>
<form>
<input v-model="model.someProperty">
</form>
</div>
</template>
<script>
export default {
data() => ({model: {someProperty:''}}),
props: ['feedbackId'],
created() => {
if (!this.$props['feedbackId']) {
return;
}
// otherwise do ajax call and populate model
// ... details omitted
},
watch: {
'$route' (to, from) {
if (to.path === '/create/feedback') {
this.model = {}
}
}
}
}
</script>
Why is this? Why do I need watch?
I would have though that changing routes would be sufficient as the purpose of routing is to mimic the semantic behavior of page navigation
You have same component for different routes, when you go to edit route from the create route component is already created and mounted so the state of the component doesn't clear up.
Your component can listen to route changes using $router provided by vue-router every time the route changes the watcher is called.
For those who come this later, the following answer addresses the issue I was facing:
Vue-Router: view returning to login page after page refresh

Best Practice for Reacting to Params Changes with Vue Router

When using Vue Router with routes like /foo/:val you have to add a watcher to react for parameter changes. That results in somewhat annoying duplicate code in all views that have parameters in the URL.
This could look like the following example:
export default {
// [...]
created() {
doSomething.call(this);
},
watch: {
'$route' () {
doSomething.call(this);
}
},
}
function doSomething() {
// e.g. request API, assign view properties, ...
}
Is there any other way to overcome that? Can the handlers for created and $route changes be combined? Can the reuse of the component be disabled so that the watcher would not be necessary at all? I am using Vue 2, but this might be interesting for Vue 1, too.
One possible answer that I just found thanks to a GitHub issue is the following.
It is possible to use the key attribute that is also used for v-for to let Vue track changes in the view. For that to work, you have to add the attribute to the router-view element:
<router-view :key="$route.fullPath"></router-view>
After you add this to the view, you do not need to watch the $route anymore. Instead, Vue.js will create a completely new instance of the component and also call the created callback.
However, this is an all-or-nothing solution. It seems to work well on the small application that I am currently developing. But it might have effects on performance in another application. If you really want to disable the reuse of the view for some routes only, you can have a look at setting the key's value based on the route. But I don't really like that approach.
I used this variant without :key prop on router-view component.
routes.js:
{
path: 'url/:levels(.*)',
name: ROUTES.ANY_LEVEL,
props: true,
component: (): PromiseVue => import('./View.vue'),
},
view.vue
<template>
<MyComponent :config="config" />
</template>
---*****----
<script>
data: () => ({ config: {} }),
methods: {
onConfigurationChanged(route) {
const { params } = route
if (params && params.levels) {
this.config = // some logic
} else {
this.config = null
}
},
},
beforeRouteUpdate(to, from, next) {
this.onConfigurationChanged(to)
next()
},
}
</script>
Inside the component, I use the config as a property. In my case, reactivity is preserved and the component is updated automatically from parameter changes inside the same URL.
Works on Vue 2
vue3 and script setup:
watch(route, () => { fetch()})
in import:
import { watch } from 'vue';
import { useRoute } from 'vue-router';
const route = useRoute()