Vue 3: How to Access Setup Variable in Component Function

user_1142348 0
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Consider the following simple example using the composition API in Vue 3. I'm trying to have an instance of test available in the functions of my component.

<script>
import { defineComponent, ref, onMounted } from 'vue'

export default defineComponent({
  name: 'Test',
  setup(){
    let test = ref()
    
    onMounted(() => {
      doSomething()
    })

    return{
      test,
      doSomething
    }
  }
})

function doSomething(){
  console.log(test) //<-- undefined
  console.log(this.test) //<-- undefined
}
</script>

How do I access test inside doSomething()? My understanding is that anything returned by setup() should be available throughout the component much like a data() attributes from the options API.

vuejs3 vue-composition-api vue.js javascript
1 Answers

you have to pass the ref as a parameter

<script>
import { defineComponent, ref, onMounted } from 'vue'

export default defineComponent({
  name: 'Test',
  setup () {
    let test = ref(null)

    onMounted(() => {
      doSomething(test.value)
    })

    return {
      test,
      doSomething
    }
  }
})

function doSomething (param) {
  console.log(param); // null
}
</script>

another approach:

// functions.js
import { ref } from 'vue'
export let test = ref(null)

// vue-file
<script>
import { defineComponent, ref, onMounted } from 'vue'
import { test } from '../utils/functions.js'

export default defineComponent({
  name: 'Test',
  setup () {

    onMounted(() => {
      doSomething(test)
    })

    return {
      test,
      doSomething
    }
  }
})

function doSomething (param) {
  console.log(test.value); // <-- instant access
  console.log(param.value); // <-- import via parameter
}
</script>
user_118691000
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