Passing arguments with $emit - Vue

Question

Passing arguments with $emit - Vue

Here is a simple method to handle alerts using $emit. But when passing arguments, it seems like the event is not being triggered at all. The goal is to update the value of alert with the result.

Listening for the event on mount:

this.$eventHub.$on('alert', data =>       
  this.alert = data
})

Works as Expected:

The value of this.alert is set even though it was initially undefined.

this.$eventHub.$emit('alert')

Doesn't Work:

The value of this.alert remains unchanged and the event is not recognized.


this.$eventHub.$emit('alert', {'message':'Signal Test', 'color':'error'})

What could be causing this behavior?

javascript vue.js

Answer 1

Answer №1

If you want to trigger an event from a vue component, you can achieve this using this.$emit. Consider the following example:

<template>
    <myComponent @customEvent="myCallback($event)" />
</template>

Here is the script code:

export default {
  methods: {
    myCallback(data) {
      console.log(data); // This will display the event data
    }
  }
}

In the child component, you need to emit the event like this:

export default {
  methods: {
    onClick() {
      // Use this.$emit(eventname, data);
      this.$emit('customEvent', 'some data');
    }
  }
}

Answer 2

If you want to trigger an event from a vue component, you can achieve this using this.$emit. Consider the following example:

<template>
    <myComponent @customEvent="myCallback($event)" />
</template>

Here is the script code:

export default {
  methods: {
    myCallback(data) {
      console.log(data); // This will display the event data
    }
  }
}

In the child component, you need to emit the event like this:

export default {
  methods: {
    onClick() {
      // Use this.$emit(eventname, data);
      this.$emit('customEvent', 'some data');
    }
  }
}

Answer 3

Answer №2

Instead of providing a solution, I realized that the issue stemmed from user error. It turns out that I was triggering the event and listening for it in the same component. However, by simply relocating the listener to a different component while keeping the code the same, the issue was resolved.

Although this could be intentional design, the lack of output in the console made it unclear whether this behavior was expected or if it was a bug.

I would greatly appreciate any insights or explanations on why this phenomenon occurs!

Answer 4

Instead of providing a solution, I realized that the issue stemmed from user error. It turns out that I was triggering the event and listening for it in the same component. However, by simply relocating the listener to a different component while keeping the code the same, the issue was resolved.

Although this could be intentional design, the lack of output in the console made it unclear whether this behavior was expected or if it was a bug.

I would greatly appreciate any insights or explanations on why this phenomenon occurs!

Passing arguments with $emit - Vue

Answer №1

Answer №2

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