I have a component that represents an option in a form, with data representing the currently selected option. There is a parent component which represents the full form, with a submit button and a reset button. I keep track of what options are currently selected in the form by emitting events from the child to the parent (this is important because the form updates dynamically)
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I'm trying to design the reset button, which clears all fields in the form (sets the currently selected option to an empty string). I would need to modify the data of the child component. Should I do this using a Vue instance as a bus? That seems overkill. Is there a better way to design these components?
I think you want to use sync on the properties your passing into the child component. I use it to load my child component like:
<textbox :content.sync="new_comment" placeholder="Add a comment..."></textbox>
If you already emitting from your child component then changes to new_comment will automatically be passed through.
You can find a lot of ways to do this here.
For me, after a lot of playing around with props, i found that the best and safest way is to use this.$refs.
Even if you have more than one child component with the same ref name, you can go through each child with a forEach.
You can create a custom event to listen to the reset button on each form field. Check out the documentation for this here
Just put a method in the child, perhaps Clear, and call it from the parent. You use $refs in the parent to get to the children.
Related
how could a pass a click event from one component to two parents up.
I have a form with a bottom clear, this form component is in a file filterForm
the filterform component is called in another file called TableView and the tableView component is called in a file called Admin
I want to execute a function inside admin when the button clear is clicked
the button is in the file filterForm
the filterForm is used in TableView
and tableView is used in Admin
this is the function I want to call from Admin to test
I understand that I have to make a click event from fileForm and emit that event to Tableview, but the function is on Admin that contains all the data and methods.
Thanks for your help!
Based on $emit event in Vue.js: https://vuejs.org/guide/components/events.html
When you emit an event like this: $emit('someEvent'), the parent someEvent function will fire (and also you can pass some parameters).
Passing a data or emitting a function so that two parents up listens to your event and get the data will need some chaining.
Fire the event on 1st component and get it in 2nd component and then fire the event in 2nd component to get it in 3rd.
Edit: one of the best practices is to use Vuex(Pinia) as a state management tool to pass or get data in an easier and cleaner way.
I am new in VUE.JS but i have finished some beginner courses of vuemastery. Though I know how to bind properties and how to emit custom events, I have a problem: I don't know how to make these things through multiple levels of components.
Let's say we have the following hierarchy:
I need to have control on the Home component's properties from the Elements and Input components from the bottom of the diagram. Right now I am emitting custom events from level to level from down to up, but it doesn't look like an elegant solution.
Is there a better way to do this? And of course when I change one of the properties from Input component it need to have effect on the properties in the Element components as well.
For example the Element components are elements having width and height calculated based on totalWidth property, which can be edited in the Input component. I'm having here a warn as well in the console: [Vue warn]: Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders.
Use this.$root.$emit to emit event on the root component, that would then propagate event on its child components, regardless of depth level
I would recommend using vuex to manage the state of your application. Emitting events all over the place is not the most elegant solution.
In Vuejs, I have a parent component (P), and two child components (C1 and C2). The parent has objects which it shares with both child components.
Component C1 displays the objects (in a table) and component C2 lets the user modify the properties of the shared objects. Because the objects are shared as objects, I am updating their properties directly in C2, and the changes are displayed in C1.
The problem is that C1 is responsible for saving changes (by making an ajax call to the server). If the user modifies a property directly in C1, it triggers the change event, and an event handler makes the call. However if the property is updated in C2, the change event is not fired in C1, so the change is not persisted.
So, the question is, how do I fire a change event in C1, based on an event in C2? I have an event bus in place (in the root element). I could (perhaps) use an event listener to grab the element (e.g. with jQuery), and fire the event, but obviously this is not the most elegant way to do it. What's the Vue way?
I hope I understood you correctly: You're sharing an object between two children and you're manipulating that object in either child component directly?
That pattern itself is the problem. You don't want to manipulate state inside a child component. The clean way that'll keep the reactiveness is to bind the object via a prop from the parent to both child components. The children should never manipulate the state of the prop object (vue should actually throw a warning if you do that), they should only emit an event that they want to change the object by using:
this.$emit('input', newObject)
Now simply listen to that event in the parent and manipulate the object there, or, for simplicity you can also use the v-model pattern as described here.
<c1 #input="myUpdateFunction" />
or with the v-model pattern
<c1 v-model="mySharedObject" />
That's it. If your other component has the same object bound to it as a prop as well, it'll update its template automatically.
If you want an even more elegant way to share state for an entire application I suggest using Vuex.
Your question it is not too clear.However you can use eventBus and it will work fine.
My recommendation though,is to use vuex.
You can manipulate the store properties and whenever the properties changing,the changes will be reactive and applied to all components.
So if you have two components c1 and c2,and in store you have a property name: 'John Doe'.
If in c1 component you change the name like: this.$store.state.name = 'Jane Doe' this change has also take effect to component c2.
Of course it is not so simple.In vuex store you should have state,getters,mutation,actions and on your components to use computed properties to use fetch the store properties though getters.
Suppose I have a tree of component like this:
<widget>
<widget-header>
<panel-toggle></panel-toggle>
</widget-header>
<widget-body>
<panel></panel>
</widget-body>
</widget>
Now supposed I want the panel-toggle component to be able to toggle the visibility of the panel component. I could have it affect a prop passed down from widget through to each component, but that didn't seem like the best solution. I tried sending an event with this.$emit(eventName) but the event is only picked up by the immediate parent of the element emitting the event. In this case, that would be panel-toggle emitting the event and only widget-header being able to pick it up. I tried sending the event across the root element with this.$root.$emit(eventName) and picking it up with this.$root.$on(eventName), but then it is picked up by all widget components and that is no good. What I ended up doing is sending the event with this.$parent.$parent.$emit(eventName) and then picking it up from panel with this.$parent.$parent.$on(eventName). While that worked, it doesn't seem like the right way to go about this.
What would be the correct way to achieve this communication between components within the component widget only with Vue? Is the answer somehow related to the ref feature?
Since you're concerned (and with good reason) about the globalness of a global event bus, the solution is a localized event bus. Create a data item in the parent:
panelBus: new Vue()
and pass it to each of the children as a prop. Now they have a private communcation channel for just the two of them.
I have a requestion, how about vue.js's common component's best practice when communicating with different parent component.
for example, in my scenario, a basic modal component, trigger a 'close' method, but it has two different parent component
I find two solutions:
parent need pass an additional prop, and then baisc component just
trigger event which event's name is the prop value, so the listener
parent component attched on could be called
in basic modal just use this.$parent to visit parent component methods, or this.$parent.trigger('xxx'), and then parent knows what to do
But, both above I think not very good, the first may need pass an additional prop, this let others who write a third, a forth parent component use the basic component not very handy. And the second may be felt more hard coded.
So, is there is better solution in this case?
Use this.$dispatch('eventName', data) (for Vue 2.x, use this.$emit('eventName', data)), to trigger an event to any parent, grandparent and further up the chain (you can use this.$broadcast('eventName', data) to trigger events down the chain in Vue < 2.x).
If the parent has an event called 'eventName' then it will fire this event.
If you have multiple parents, you can give them each a different event and from the child fire this specific event via dispatch. You can also give each parent the same event and pass a data prop that specifies what the parent should do. Third option is to refer to the specific parent:
var parent = new Vue({ el: '#parent' })
// access child component instance
parent.$refs.eventName()
Each option has pros and cons. The best solution depends on the context. But I think that the best solution in general is option 1. Then you don't need an additional data parameter. Option 3 is not loosely coupled.
For more info: https://vuejs.org/guide/components.html