How to set data value of other component in vue js? - vue.js

I have two component for example Login.vue and Header.vue. I want to set data value of header.vue after some action in login.vue. how can i do so?I am using vue cli.

If your Login Component is a child of your header, then your Login can emit an event. See here.
If not, then your components can exchange data via a Global Event Bus
or a global store Vuex.
Also take a look here on cross component communication.

Related

If I have multiple components with input fields in vue router, how should I fetch data and store it in vuex?

In my vue cli project I have a route Settings with 3 child components SettingsA, SettingsB and SettingsC. Each child component has ca. 15 input fields, so it would be too many input fields for one single component.
The goal is to get data from a REST backend with an an axios call when the Route Settings is loaded, and populate some of the input fields with the data;
the user can then navigate between the child components and fill/change the input fields, without triggering the axios call which would reload and overwrite the users input field changes.
Since there are 3 child components I use vuex as store. That way the users inputs should not change when he navigates between the child components.
My question is: Where and with what hook should I make the axios call? With beforeMounted on the Settings Component?
Maybe there is also a better, already tried design than mine?
Thanks for your help!
Solution using custom events
You actually not necessarily need vuex. Basic idea is to have parent component Settings, which includes SettingsA, SettingsB and SettingsC, which are displayed conditionally using v-if. The Settings component is holding your state. Changes in the child components form fields trigger events with this.$emit(). The parent component listens to the events and updates its state. The state of the form is passed down via props.
Solution using Vuex actions
If you go the Vuex route, you will trigger actions instead of using this.$emit() and update the global store. You should import the actions using mapActions. In your components you then have access to the global store using this.$store.

Vue JS Components structure

I am learning Vue and my doubt is about the structure of my Vue app.
I learnt that the components can include both logic and template. Then I separated my components and everyone is getting the config from the main app (config is an object with the coordinates config.ll, config.lng).
I do the ajax call to my search-and-discovery API service and I display the results inside each components (current location, venues-near-you etc).
My question is: is it correct to encapsulate the calls into each components? Or is it better to get the needed data inside the general app and then share the results with the components using pros?
I am asking that because the hard part is starting now when I want to communicate the click of a category to the venuesNearYou component, I tried to use the emit without success.
//MAIN
<sidebar :config="config"></sidebar>
<content :config="config"></content>
//IN SIDEBAR
<currentLocation :config="config"></currentLocation>
<categories :config="config"></categories>
//IN CONTENT
<venueDetails :config="config"></venueDetails>
<venuesNearYou :config="config"></venuesNearYou>
I think you could use event Bus like approach
we have three type of communication in vue app (without vuex)
Parent to child communication which is full field by props
child to parent communication handle by custom event from child which is listen by parent
communication between non parent child component in which we use event bus approach
Parent to child example
Child to parent example
In child this.$emit('sendDataToParent',{someData:"some data"}})
in parent
<child-component :somedata="dataToChild" #sendDataToParent="'gotsomedata from parent'">
Event Bus
in main vue instance
const eventBus = new Vue()
in some component from where to send data
import eventBus
eventBus.$emit('someEvent','some data')
in some component from where to receive data
created() {
// register listener
eventBus.$on('someEvent',()=>{
})
}
For more reference
https://v2.vuejs.org/v2/guide/components.html#Passing-Data-to-Child-Components-with-Props
https://v2.vuejs.org/v2/guide/components.html#Emitting-a-Value-With-an-Event
https://medium.com/easyread/vue-as-event-bus-life-is-happier-7a04fe5231e1
It's hard to help you around emitting an event since you didn't provide much of a code. But check Vuex. It serves as a centralized store for all the components in Vue application.

Emit data between components (Event listener in vue?)

I'm kind of new to Vue and I'm trying to emit data between different components.
I have 2 components I need to emit their data together:
First component is the Item Selector.
Second component is Filter Navigation Bar.
the logic:
The navigation bar contains a filter section, I've created an ItemSelector component and import it to the navigation bar.
I want the data selected in the item selector will be emited to the container and a table will be draw by that information.
I created the logic of the table, and tried to import the item selector component directly to the container and passing the data using emit, and it worked great.
The problem is I've added one more page to the cycle.
Right now, the ItemSelector component emits its data to the FilterContainer component, and now this data should be emited to the container!
Is there any way to catch all those events in a seperate component, compute the data and emit it all over the app?
You can use a global event bus which can listen/emit event on global scope of your app.
Another approach is using vuex which store all global states of your app.
If you have small app, i think you should use event bus because it simpler than vuex.

Vue.js router-view mounted callback

I'm using Vue.js with Vue-router in a project and I'm trying to have a callback whenever the routed-to component is ready. Usually you would do it inside each component in the mounted() hook, but for this case I want it for every component that has been routed to.
I tried with router.OnReady() and router.afterEach() but it did not work since they happen after routing but before the component is mounted. I also tried changing the vue-router source code adding mounted() to the router-view component, but it's not getting called.
There is no on-router event for this but according to this issue you can get around this by using Vue.nextTick inside router.afterEach.

Mutations using Relay Environment

I'm using Relay with React Native and have a problem during login & logout.
After login or logout, Relay keeps the store from the previous user. To solve this I use Relay.Renderer and Relay.Environment. As in, in each Renderer I put singleton object of Environment.
The problem is that I previously did a mutation on object of Relay.Store, as in
Relay.Store.commitUpdate(new CreateProfile(), callback).
Now it doesn't work. I guess this is because Relay.Store doesn't know anything about server endpoints. But Relay.Environment does.
And now I'm using something like this this.props.relay.commitUpdate(new CreateProfile(), callback). It works pretty well when the parent component is wrapped as Relay.Container, so it has relay object in props.
But what should I do in components which are not Relay.Containers and don't have Relay object in props?
Relay.Store is a globally accessible singleton instance of Relay.Environment and Relay.Store.commitUpdate() updates data in that global environment. But since you're using your own instance of Relay.Environment, to update it you need to use this.props.relay.commitUpdate(), as you noted. This updates the environment the container was rendered with.
If need to make mutations from child components of containers, that are not wrapped in a Relay.Container, there are two ways to do that. You could simply pass the relay prop to them, so in the render function of your container you would have:
<Child relay={this.props.relay} />
However, since those plain components are not in a Relay container, they don't currently need to know anything about Relay. If you want to keep them that way, you could write the method that does the update in your container component like this:
onCreateProfile = () => {
this.props.relay.commitUpdate(new CreateProfile());
};
and only pass a callback to your child component in render:
<Child onCreateProfile={this.onCreateProfile} />
If you need to make a mutation from a component that does not have a Relay.Container above it in the component hierarchy at all, you could create the Relay.Environment in a shared root component higher up and pass it down using props (or pass a callback using the strategy shown above).