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

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.

Related

Why is this.$route.params null?

I want to pass data to another page and I use the following code:
this.$router.push({ path: '/guard/foreigner-list', params: data});
Then I expect item is equal to data, but item is null
let item = this.$route.params;
You did not posted the entire code that is related to the process of changing route. But according to Vue Router documentation:
params are ignored if a path is provided, which is not the case for query, as shown in the examples. Instead, you need to provide the name of the route or manually specify the whole path with any parameter
So if you have defined a route called user in your router.js file like below:
import User from "../views/User"
const routes = [
{
path: '/user/:id',
name: 'User',
component: User
}
]
Then you can navigate programmatically from Home.vue to User.vue with the codes below:
Home.vue:
<template>
<div class="home">
<button #click="navigFunc">click to navigate</button>
</div>
</template>
<script>
export default {
name: 'Home',
methods: {
navigFunc: function () {
const id = '123';
// using "name" not "path"
this.$router.push({ name: 'User', params: { id } });
}
}
}
</script>
User.vue:
<template>
<section>
<h1>User page</h1>
</section>
</template>
<script>
export default {
name: "User",
mounted() {
/* access the params like this */
console.log(this.$route.params)
}
}
</script>
<style scoped>
</style>
Notice that the variable I defined (id), is the same as the params that was defined in router.js (path: '/user/:id').
Start from vue-router#4.1.4 (2022-08-22) passing object through params is no longer a viable option, since it is consider as anti-pattern.
However,
there are multiple alternatives to this anti-pattern:
Putting the data in a store like pinia: this is relevant if the data is used across multiple pages
Move the data to an actual param by defining it on the route's path or pass it as query params: this is relevant if you have small pieces of data that can fit in the URL and should be preserved when reloading the page
Pass the data as state to save it to the History API state: ...
Pass it as a new property to to.meta during navigation guards: ...

Paginated async Component doesn't trigger setup() on route change

I have a paginated component. The async setup() method is pulling data from an API to populate the page. It works fine when the route is directly loaded, but when I change the route to a different page slug (eg. clicking a router-link), the component is not reloaded and setup is not executed again to fetch the new data.
I guess I somehow want to force reloading the component?
This is my MainApp component it has the router view and fallback.
<router-view v-slot="{ Component }">
<Suspense>
<template #default>
<component :is="Component" />
</template>
<template #fallback>
loading...
</template>
</Suspense>
</router-view>
The router looks kinda like that. You see the page component takes a page_slug:
const routes: Array<RouteRecordRaw> = [
{
path: "/",
name: "",
component: MainApp,
children: [
{
name: "page",
path: "page/:page_slug",
component: Page,
props: true,
},
// [...]
]
}
And this is how my Page component looks like. It uses the page_slug to load data from an API which is then used in the template:
<template>
<div> {{ pageData }} </div>
</template>
export default defineComponent({
name: "Page",
props: {
page_slug: {
type: String,
required: true,
},
},
async setup(props) {
const pageData = await store.dispatch("getPageData", {
page_slug: props.page_slug
});
return { pageData }
}
}
When I directly open the route, the fallback "loading..." is nicely shown until the data is returned and the component is rendered.
But when I do a route change to another page, then async setup() is not executed again. In that case the url in the browser updates, but the data just remains the same.
How can I solve this case? Do I have to force reload the component somehow? Or have an entirely different architecture to the data loading?
The answer is simple, when trying to create Vue 3 Single File Components (SFCs) in Composition API way as shown below:
<template>
<!-- Your HTML code-->
</template>
<script>
export default {
name: 'ComponentName',
async setup():{
// Your code
}
};
</script>
<style>
/*Your Style Code*/
</style>
<script>, will only executes once when the component is first imported. So, when the data have changed by other component, the component above will not updated or in other words not re-created.
To make your component re-created whenever it about to mount, you have to use <script setup> which will make sure the code inside will execute every time an instance of the component is created, but you need to re-write your script code with few changes in comparison when using setup() method, and also you are able to use both of scripts like this:
<script>
// normal <script>, executed in module scope (only once)
runSideEffectOnce()
// declare additional options
export default {
name: "ComponentName",
inheritAttrs: false,
customOptions: {}
}
</script>
<script setup>
// executed in setup() scope (for each instance)
</script>
Read this documentation carefully to have full idea.

Fetching data from parent-component after reload a route with vue and vue-router

I have a component showing multiple routes (Step1, Step2, Step3...) on after each other. I navigate and pass properties like
<router-view
#next-button-step1="
$router.push({
name: 'Step2',
params: { myprop: thisprop },
})
"
[...]
</router-view>
with the routes defined like
const routes = [
{
path: "/s2",
name: "Step2",
component: Step2,
props: true,
},
This works well, until I reload a page/route, because the the data is lost. So I kind of want to fetch the data from the parent, after the component is loaded.
One of my ideas was using the local storage, but this does not feel right.
I am a newbie to Vue and I would like to ask what's the best practice here. Is it vuex like described here Reload component with vue-router? I'd appreciate a hint.
If localStorage is suitable depends on the use case.
You say that data is lost when you reload the page/route. It's perfectly possible to store this data to prevent data-loss on route change/reload. But changing/reloading the page will only be solved either by storing data in localStorage (and retrieving from localStorage on page init), or storing it on the server and retrieving it on page init...
Vuex may help you with the route change/reload part, but even Vuex won't help you with the page change/reload.
I will show you an example of how to save the data for the first case: route changes and reloads, because this may be achieved without adding Vuex. We will do this by having the data inside a parent component and passing this data to our routes. When a route changes the data it should emit an update-event (including the updated data) and the parent should store the changed data.
I'll show an example scenario in which the parent holds all the data. The routes
are responsible for editing different aspects of the data. Each time i switch between a route the parent supplies the data.
A working example can be found here: https://jsfiddle.net/b2pyv356/
// parent component / app.vue
<template>
<div>
<router-view
:state="state"
#updatestate="updateState"
></router-view>
<pre>Parent state: {{state}} </pre>
</div>
</template>
<script>
export default {
data() {
return {
state: {
name: 'name',
lastname: 'lastname'
}
}
},
methods: {
updateState(state) {
this.state = state;
}
}
};
</script>
// page1.vue
<template>
<div>
Route 1: State is:
<pre>{{state}}</pre>
<div>
Name: <input v-model="state.name">
<button #click="$emit('updateState', state)">Save</button><br>
</div>
<router-link to="/page2">Next step</router-link>
</div>
</template>
<script>
export default { props: ['state'] }
</script>
// page2.vue
<template>
<div>
Route 2: State is <pre>{{state}}</pre>
Name: <input v-model="state.name">
<button #click="$emit('updateState', state)">Save</button><br>
<router-link to="/">Previous page</router-link>
</div>
</template>
<script>
export default { props: ['state'] }
</script>
Persisting data:
On updateState you could store the data in localStorage
You could store some data in the request url ($router.params) or page query string. This has limits: some browsers enforce limits on how long a url may be. You are also responsible to validate/sanitize incoming data, do not trust that it won't be tempered with. Same applies to localStorage data btw. Common cases include storing a search query: if you refresh the page you still have the search query.
Let the backend save the data and retrieve the user's data on page load.

Where should route meta data be loaded in a Vue app?

I'm in the process of setting up a VueJs SPA. I'm using vue-router and I'm trying to find the best solution to the following problem. I have a series of routes. Each of which needs to call an API to get the meta data for the given ID.
/industry/:id/overview
/industry/:id/top-stories
/industry/:id/top-tweets
/brand/:id/overview
/brand/:id/top-stories
/brand/:id/top-tweets
I've been looking at using created or beforeRouteEnter/beforeRouteUpdate and I'm a bit lost. Ideally, I would only fetch new data when a new /industry/:id is reached, not when navigating between pages within the same ID. Also, I'd like to avoid having to define the fetch to grab data in every page component. Also don't want to over complicate this, so my question is, Is there a standard method for tackling this issue?
Clarification:
When I say meta here, I mean data returned from an API about the given industry or brand which I pull using the ID in the route. The api call includes the name of the industry/brand which I want to have on page as soon as the page is presented to the user.
I have something similar. I tackle this using the following approach:
I use the same component for all /industry/:id Vue likes to reuse components wherever it can so if two routes (for example /industry/:id/overview and /industry/:id/top-stories) are using the same component it will stay the same.
What does change, however, is the route meta. So if you add a page key to the meta object in the route objects, and probably add a computed property called page that return this.$route.meta.page, you can use v-if attributes to conditionally render any component. So you might have something like <div v-if="page === 'overview'"></div><div v-else-if="page==='top-stories'"></div>
What this allows you to do is fetch all the data from the API during created or mounted lifecycle and store it as the state. Since the route change doesn't reload the component the state stays the same.
Here is a code example
// router.js
const Project = () =>
import(/* webpackChunkName: "projects" */ "./views/projects/_id");
export default new Router({
mode: "history",
routes: [
{
path: "/projects/:project_id/views",
name: "ViewProject",
component: Project,
meta: {
page: "views",
}
},
{
path: "/projects/:project_id/export",
name: "ExportProject",
component: Project,
meta: {
page: "exports"
}
},
{
path: "/projects/:project_id/recommendations",
name: "ProjectRecommendations",
component: Project,
meta: {
page: "recommendations"
}
},
]
});
And here is the template
<template>
<div v-if="project">
<h1>{{ project.name }}</h1>
<router-link :to="/project/someid/views">Views</router-link>
<router-link :to="/project/someid/exports">Exports</router-link>
<router-link :to="/project/someid/recommendations">Recommendations</router-link>
<ul v-if="page==='views">
<li v-for="(view, i) in project.views" :key="i">{{ views }}</div>
</ul>
<ul v-else-if="page==='exports">
<li v-for="(export, i) in project.exports" :key="i">{{ export }}</div>
</ul>
<ul v-else-if="page==='recommendations">
<li v-for="(recommendation, i) in project.recommendations" :key="i">{{ recommendation }}</div>
</ul>
</div>
</template>
<script>
export default {
data() {
return {
project: null
}
},
computed: {
page() {
return this.$route.meta.page;
}
},
mounted() {
this.getProject()
},
methods: {
getProject() {
axios
.get(`/projects/someid`)
.then(res => this.project = res.data)
}
}
}
</script>

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