async wait not working in composable function vue 3

Question

In my project, I have a function to download files. When the button is clicked, function onDownload will be called:

import {useOnDownload} from "../../use/useOnDownload"

setup() {

    ...

    const loading = ref(null)
    onDownload = (id) => {
        loading.value = id
        await useOnDownload(id)
        loading.value = null
    }
    
    return {loading, onDownload}
}

I refactored the api code in the useOnDownload.js calling file because other components also use the same code.

export async function useOnDownload(id) {
    // make api call to server with axios
}

What did i do wrong? I need to wait for the function useOnDownload ... for the loader to work properly.

Answer 1

The following is how to use async wait syntax to create an asynchronous composable function

export default function useOnDownload() {
  const isLoading = ref(true);

  const onDownload = async () => {
    isLoading.value = true;
    try {
      const { data } = await axios.post('/api/download', {id: id}, 
     {responseType: 'blob'})
        // handle the response

    } catch (error) {
      console.log(error);
    } finally {
      isLoading.value = false;
    }
  };
   // invoke the function
  onDownload();

  return { // return your reactive data here };
}


import useOnDownload from "../../use/useOnDownload"
// no await in setup script or function 
const { reactiveDataReturned } = useOnDownload();

Clickherefor more information

Answer 2

I managed to solve another way without async and await...

I pass the reference object loader to the function argument (as optional) and handle it from there...

export function useOnDownload(id, loader) {
   if(loader !== undefined) {
     loader.value = id
   }
   axios.post('/api/download', {id: id}, {
      responseType: 'blob'
   }).then(response => {
     // handle the response
     ...
     if(loader !== undefined) {
       loader.value = null
     }
   }).catch(error => {
     // handle the error
     ...
     if(loader !== undefined) {
       loader.value = null
     }
   })
}