Why are the $refs always empty or undefined within Vue components?

Question

Why are the $refs always empty or undefined within Vue components?

I am completely new to working with Vue and I've been attempting to utilize $refs to retrieve some elements within the DOM from a sibling component. My objective is very basic, as I just need to obtain their heights, but I haven't had much success so far despite my efforts. I have been trying to do this within a computed property.

Regardless of what methods I use, this.$root.$refs consistently turns out to be either undefined or an empty object. I'm at a loss as to where I may be going wrong.

In the parent component, my setup looks like this:

<template>
  <ComponentA />
  <ComponentB />
</template>

Within Component A, my code is structured as follows:

<template>
  <div id="user-nav">
   <div ref="nav-container">
    <slot />
   </div>
  </div>
</template>

My approach has simply been to try accessing this in Component B by using console.log

console.log(this.$root.$refs);

within the mounted function of that particular component.

However, all I get is an empty object returned every time.

Is it not possible to access elements across sibling components in this manner???

javascript vue.js ref

Answer 1

Answer №1

If you've already tackled this issue, here's a possible solution:

Dealing with a similar problem, it appears that the function is being called before Vue fully replaces the root DOM. To rectify this, establish a mounted life-cycle hook and invoke the function within.

const app = new Vue({
  el: '#app',
  data: {
    greeting: 'Hello World',
  },
  mounted: function() { // This hook ensures Vue has completed its process.
    console.log('YOUR ELEMENT ----> ', this.doSomething())
  },
  methods: {
    doSomething: function() {
      return this.$refs['nav-container']
    }
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
  <span ref="nav-container">{{ greeting }}</span>
</div>

The resolution can be found here.

Answer 2

If you've already tackled this issue, here's a possible solution:

Dealing with a similar problem, it appears that the function is being called before Vue fully replaces the root DOM. To rectify this, establish a mounted life-cycle hook and invoke the function within.

const app = new Vue({
  el: '#app',
  data: {
    greeting: 'Hello World',
  },
  mounted: function() { // This hook ensures Vue has completed its process.
    console.log('YOUR ELEMENT ----> ', this.doSomething())
  },
  methods: {
    doSomething: function() {
      return this.$refs['nav-container']
    }
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
  <span ref="nav-container">{{ greeting }}</span>
</div>

The resolution can be found here.

Answer 3

Answer №2

I encountered a similar issue where I was utilizing this.$refs within a computed property. Upon making the decision to replace computed properties with methods, my problem was resolved. It turns out that $refs are not reactive, as discussed in references such as here and here

Answer 4

I encountered a similar issue where I was utilizing this.$refs within a computed property. Upon making the decision to replace computed properties with methods, my problem was resolved. It turns out that $refs are not reactive, as discussed in references such as here and here

Answer 5

Answer №3

While this may not directly address your specific issue, I came across another possible explanation for why $refs might be empty. It could be that the component where it is defined has not yet been created or mounted, possibly due to Vue's lazy rendering mechanism.

In my case, I had a series of tabs, one of which contained the element with a "ref" attribute. If I didn't visit that particular tab, then the $refs array remained empty. However, once I navigated to that tab first, the reference was established correctly.

Answer 6

While this may not directly address your specific issue, I came across another possible explanation for why $refs might be empty. It could be that the component where it is defined has not yet been created or mounted, possibly due to Vue's lazy rendering mechanism.

In my case, I had a series of tabs, one of which contained the element with a "ref" attribute. If I didn't visit that particular tab, then the $refs array remained empty. However, once I navigated to that tab first, the reference was established correctly.

Answer 7

Answer №4

It's definitely possible, but the issue you're facing is that there are no references in your parent component.

I wouldn't recommend going down this route, it's better to use vuex, an eventbus, or $emit instead.

Vue.component('componentA', {
  template: '<div><span ref="ref-inside-a">You\'re in A!</span></div>',
  methods:{
  log(){
  console.log('Hello from a')
  }
  }
})

Vue.component('componentB', {
  props: ['ball'],
  template: '<div><span>This is B!</span></div>',
  mounted() {
    this.$root.$refs['a'].log()    
    console.log(this.$root.$refs['a'].$refs['ref-inside-a'])
  }
})

new Vue({
  el: "#app",
  mounted() {
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
  <component-a ref="a"></component-a>
  <component-b ref="b"></component-b>

</div>

Answer 8

It's definitely possible, but the issue you're facing is that there are no references in your parent component.

I wouldn't recommend going down this route, it's better to use vuex, an eventbus, or $emit instead.

Vue.component('componentA', {
  template: '<div><span ref="ref-inside-a">You\'re in A!</span></div>',
  methods:{
  log(){
  console.log('Hello from a')
  }
  }
})

Vue.component('componentB', {
  props: ['ball'],
  template: '<div><span>This is B!</span></div>',
  mounted() {
    this.$root.$refs['a'].log()    
    console.log(this.$root.$refs['a'].$refs['ref-inside-a'])
  }
})

new Vue({
  el: "#app",
  mounted() {
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
  <component-a ref="a"></component-a>
  <component-b ref="b"></component-b>

</div>

Answer 9

Answer №5

In my particular situation, the

this.$refs

element was referenced in multiple components. I was able to access a specific component using its reference:

this.$refs[componentName]

To retrieve a particular field from the component mentioned above, I had to choose the first observable:

this.$refs[componentName][0].someFieldToBeSelected -> this is successful
this.$refs[componentName].someFieldToBeSelected -> this does not work

.

Answer 10

In my particular situation, the

this.$refs

element was referenced in multiple components. I was able to access a specific component using its reference:

this.$refs[componentName]

To retrieve a particular field from the component mentioned above, I had to choose the first observable:

this.$refs[componentName][0].someFieldToBeSelected -> this is successful
this.$refs[componentName].someFieldToBeSelected -> this does not work

.

Answer 11

Answer №6

I encountered a similar issue, but the root cause turned out to be different:

The problem stemmed from having a v-if condition on the element being referenced. This meant that during mounting, the element was not rendered due to the condition still being false.

After spending hours trying to pinpoint the issue, the solution became glaringly obvious.

<template>
  <sub-component v-if="showCondition" ref="componentName">
    <div>someContent</div>
    <div>someMoreContent</div>
  </sub-component> 
</template>

<script lang="ts">
export default class MyComponent extends Vue {
  private showCondition = false; // set to true after a REST request
  mounted() {
    console.log(this.$refs); // this was empty
  }
}
</script>

The resolution involved moving the v-if directive to an additional template element within the referenced component.

<template>
  <sub-component ref="componentName">
    <template v-if="showCondition">
      <div>someContent</div>
      <div>someMoreContent</div>
    </template>
  </sub-component>
</template>

<script lang="ts">
export default class MyComponent extends Vue {
  mounted() {
    console.log(this.$refs); // now 'componentName' is available
  }
}
</script>

Answer 12

I encountered a similar issue, but the root cause turned out to be different:

The problem stemmed from having a v-if condition on the element being referenced. This meant that during mounting, the element was not rendered due to the condition still being false.

After spending hours trying to pinpoint the issue, the solution became glaringly obvious.

<template>
  <sub-component v-if="showCondition" ref="componentName">
    <div>someContent</div>
    <div>someMoreContent</div>
  </sub-component> 
</template>

<script lang="ts">
export default class MyComponent extends Vue {
  private showCondition = false; // set to true after a REST request
  mounted() {
    console.log(this.$refs); // this was empty
  }
}
</script>

The resolution involved moving the v-if directive to an additional template element within the referenced component.

<template>
  <sub-component ref="componentName">
    <template v-if="showCondition">
      <div>someContent</div>
      <div>someMoreContent</div>
    </template>
  </sub-component>
</template>

<script lang="ts">
export default class MyComponent extends Vue {
  mounted() {
    console.log(this.$refs); // now 'componentName' is available
  }
}
</script>

Answer 13

Answer №7

I encountered this issue in two scenarios

1- The mounted hook was mistakenly placed inside the methods section.

2- I had a ref within a v-for loop, but since the array for the loop was empty, it couldn't be properly initialized.

Answer 14

I encountered this issue in two scenarios

1- The mounted hook was mistakenly placed inside the methods section.

2- I had a ref within a v-for loop, but since the array for the loop was empty, it couldn't be properly initialized.

Why are the $refs always empty or undefined within Vue components?

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Answer №7

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