I have a bootstrap vue modal on a view page. When save is clicked, the save function emits an event. Works fine. When i close the modal and open it again then click on save, the save function is handled as expected emitting the function, however, it emits it twice (once for each time the modal was opened and closed. If i open and close the modal 5 times then click save, it calls the save function once but emits the function 5 times. I'm not sure how i can unbind the event when the modal closes using either typescript, vue, or bootstrap (any way other than jQuery :). Can anyone advise?
save() {
EventBus.$emit(MyEvents.RequestItemDetails);
}
// EventBus.ts
export const EventBus = new Vue();
export enum MyEvents{
RequestItemDetails = "request-item-details"
}
You've provided very little code for us to know what the problem actually is, but I'll take a guess.
If you're using a global event bus and you subscribe to an event on that bus from within a component, you need to make sure you unsubscribe from that event when the component is destroyed, otherwise your event handler function will be called multiple times because it gets registered multiple times on the bus.
For example:
import bus from './bus.js'
export default {
created() {
bus.$on('request-item-details', this.onRequestItemDetails)
},
destroyed() {
bus.$off('request-item-details', this.onRequestItemDetails)
},
methods: {
onRequestItemDetails() {
// Handle event
}
}
}
Your reply helped me find the solution. In my close method, all i needed to do was add "EventBus.$off('request-item-details')". That took care of it. Guilty of Overthinking again.
Thanks!
Related
New to Vue.js, trying to use the eventBus to emit events in different sibling components.
Here's the interaction I want to happen.
1. I click on a delete button on a card component.
2. A modal pops up asking to confirm the deletion.
3. User clicks OK in the modal to confirm deletion.
4. That click emits an event to the card component that triggers its delete method, finally deleting it.
My code is fine all the way to step 3 and then it just conks out.
I've been trying to use the eventBus but I'm not sure what I'm doing wrong. Here's my code starting from step 3.
props: {
jobs: { type: Array, default: null }
},
created(){
bus.$on('confirmGigDelete', () => {
console.log('running');
// What do I do here?
});
},
methods: {
deleteMyJob(id) {
console.log('this was deleted');
fetch(`${API_URL}/${id}`, {
method: "DELETE"
});
},
Is it possible to trigger confirmGigDelete this way in the HTML?
<img
:src="require('../../../assets/icons/common/deleteIcon.svg')"
id="deleteButton"
class="delete icon button"
#confirmGigDelete="deleteMyJob(job._uid)"
#click="showDeleteForm"
/>
You should avoid using the event bus in Vue as it is stated in the official documentation about dispatch and broadcast
It's better to use the event system for communication between child and parent. The child emits an event with this.$emit('event-name', payload) and the parent listens for events from its child with #event-name="myMethodInParent". This is just the good practice. The other good option is the use Vuex and to mutate state directly from child components.
Vue events docs
Vuex
I need to fire an event when page is done with rendering all the components. I have tried page mounted event but this fires only for the first time, I need to fire an event when the route changes on client side and new component is done rendering.
How about using updated . I used that for data changing state . Hope you get some help from this tips
updated: function () {
this.$nextTick(function () {
// Code that will run only after the
// entire view has been re-rendered
})
}
I am trying to leverage a Vue mixin to add behavior when a native event happens. Using a mixin will allow me to share that across several components. Specifically, when a field component (or button, or checkbox, etc.) has focus, and the Escape key is pressed, the field loses focus.
A similar Stack Overflow question seemed to indicate I could listen for native events (see code comment about multiple events).
However, the Vue Documentation for programmatically adding an event listener using $on says that it will
Listen for a custom event on the current vm...
(Emphasis added)
Unsure if the custom event remark is absolute or based on the context, I have been experimenting. I have been trying to listen for the native keyup event (using the Vue alias keyup.esc) but have had no success. So I am wondering if it is indeed limited to custom events, and if so, why?
You can see my experiment in a code sandbox. The custom event works, the native does not.
The mixin looks like so:
// escape.mixin.js
export default {
created() {
// Custom event
this.$on("custom-event", function() {
console.log("Custom event handled by mixin");
});
// Native event
this.$on(["keyup.esc", "click"], function() {
alert("Native event handled!");
});
}
};
The main point of all this is to be able to add the behavior to a set of components by adding to how the event is handled, without overriding behavior that might also exist on the component. The secondary goal is to provide the behavior by simply adding the mixin, and not having to do component level wiring of events.
So a component script would look something like this:
// VText component
import escapeMixin from "./escape.mixin";
export default {
name: "VText",
mixins: [escapeMixin],
methods: {
onFocus() {
console.log("Has Focus");
this.$emit("custom-event");
}
}
};
Also, I was trying to avoid attaching the listener to the <input> element directly with vanilla JS because the Vue documentation suggested that letting Vue handle this was a good idea:
[When using v-on...] When a ViewModel is destroyed, all event listeners are automatically removed. You don’t need to worry about cleaning it up yourself.
Solution
skirtle's solution in the comment below did the trick. You can see it working in a code sandbox.
Or here's the relevant mixin:
export default {
mounted() {
this.$el.addEventListener("keyup", escapeBlur);
},
beforeDestroy() {
this.$el.removeEventListener("keyup", escapeBlur);
}
};
function escapeBlur(e) {
if (e.keyCode === 27) {
e.target.blur();
console.log("Lost focus");
}
}
I am very new to Vue.js. In fact I just started today.
I have a problem.
Let's say I have button in a table somewhere in dom.
<table>
<tr><td><button v-on:click="showModal">Show</button>
</table>
Now I have a modal box outside of the scope of the button.
This button is inside a component of itself and the modal box has a component of itself too.
I am passing in an id with this button, and what I want to do is:
Fetch the id on button click
Show the record fetched in the modal and then finally perform some action on it
My problem is I am unable to get a method in the Modal component (that does a http request and fetches and renders the data) to trigger by the click event of this button.
The button and the modal has no relationship, they are not parent/child.
In modal component trigger method to fetch data by component ready state:
ready: function() {
this.getAllTheDataYouNeed();
},
You may use another life cycle hook:
https://vuejs.org/guide/instance.html#Lifecycle-Diagram
An option was to add the event broadcast in the common ancestor of both the components.
Like this:
var main = new Vue({
el: 'body',
components: {
zmodal : zmodal,
showhidebtn : showhidebtn,
},
methods: {
showModal: function (currentId) {
this.$broadcast('openModalBox', currentId);
}
}
});
Add an event listener in 'zmodal' and call this function showModal from on click event of 'showhidebtn' component.
It is working but now I have a set of codes outside the components that have to be triggered for this to work.
I wonder if there is a better way to do this.
Here is the example:
http://jsfiddle.net/hulufei/twr4thuh/7/
It just worked when bind onClick in virtual dom(like line 18), but If I comment line 18 and comment off line 8 to bind click with addEventListener, it failed.
So what's the problem?
TestUtils triggers events within react's synthetic event system, so the native event that addEventListener listens for is never going to be triggered. You will need to use the native click method on the element in your test:
var events = Events();
ReactTestUtils.renderIntoDocument(events);
events.refs.button.getDOMNode().click();
events.state.event.should.equal('click');
Additionally, you've misspelled clickHandler in your addEventListener definition.
jsfiddle
You can also simplify adding your event listener by reusing your prop definition:
componentDidMount: function () {
this.refs.button.getDOMNode().addEventListener('click', this.clickHandler);
},
Note:
Is there a reason why you want to use addEventListener instead of just passing an onClick attribute for your button? Unless there's a specific and good reason otherwise, i'd suggest doing things the react way when handling events for sanity :)
Edit
I originally mentioned that I did not know what TestUtils' SimulateNative.click did not trigger the event. I was wrong in thinking that it ever would since it would be simulating a native click event within the react even system. #thilo pointed me in the right direction :)
I had many problems while testing addEventListener, and I got the following conclusion.
You can create the events listener with pure javascript, jquery, but when running the tests with Jest I always had a problem.
The rendering of ReactTestUtils does not work directly with the document, and when we do:
For example, our events were added in the document, when rendering with ReactTestUtils it creates a div and renders it in the div, This way I could not get Simulate to trigger the call.
My first solution was to use jquery to create the listener and to test I did the render manually by appending the div in document.body, and triggered the events with the dispachEvent of javascript. But I thought the code was dirty, not the best way to work.
I made a sample code by adding the event and testing it with Jest, also have a test teaching to get all the listener that were created.
You can find the code here: https://github.com/LVCarnevalli/create-react-app/tree/master/src/components/datepicker
Component:
componentDidMount() {
ReactDOM.findDOMNode(this.datePicker.refs.input).addEventListener("change", (event) => {
const value = event.target.value;
this.handleChange(Moment(value).toISOString(), value);
});
}
Test:
it('change empty value date picker', () => {
const app = ReactTestUtils.renderIntoDocument(<Datepicker />);
const datePicker = ReactDOM.findDOMNode(app.datePicker.refs.input);
const value = "";
const event = new Event("change");
datePicker.value = value;
datePicker.dispatchEvent(event);
expect(app.state.formattedValue).toEqual(value);
});
Links:
window.addEventListener not triggered by simulated events: https://github.com/airbnb/enzyme/issues/426
Creating and triggering events: https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events