TypeError: Cannot read property 'cache' of undefined - VueJS - vue.js

Question

I created a Vue component which exports an async function. This component acts as a wrapper for calling my API. It's based on axios with a caching component that relies on localforage for some short lived persistence.
import localforage from 'localforage'
import memoryDriver from 'localforage-memoryStorageDriver'
import { setup } from 'axios-cache-adapter'
export default {
async cache() {
// Register the custom `memoryDriver` to `localforage`
await localforage.defineDriver(memoryDriver)
// Create `localforage` instance
const store = localforage.createInstance({
// List of drivers used
driver: [
localforage.INDEXEDDB,
localforage.LOCALSTORAGE,
memoryDriver._driver
],
// Prefix all storage keys to prevent conflicts
name: 'tgi-cache'
})
// Create `axios` instance with pre-configured `axios-cache-adapter` using a `localforage` store
return setup({
// `axios` options
baseURL: 'https://my.api',
cache: {
maxAge: 2 * 60 * 1000, // set cache time to 2 minutes
exclude: { query: false }, // cache requests with query parameters
store // pass `localforage` store to `axios-cache-adapter`
}
})
}
}
Here is how I am importing and using this component in my views:
import api from '#/components/Api.vue'
export default {
data() {
return {
userId: this.$route.params.id,
userData: ''
}
},
methods: {
loadClient(userId) {
const thisIns = this;
api.cache().then(async (api) => {
const response = await api.get('/client/find?id='+userId)
thisIns.userData = response.data.data[0]
}).catch(function (error) {
console.log(error)
})
},
},
created() {
this.loadClient(this.userId)
},
}
I can import this component and everything appears to work. I get data back from my API. However, immediately after every call, I get an error:
TypeError: Cannot read property 'cache' of undefined
Which references this line:
api.cache().then(async (api) => {
I am unable to understand why this is happening, or what it means. The error itself indicates that the component I am importing is undefined, though that's clearly not the case; if it were, the API call would ultimately fail I would suspect. Instead, I am lead to believe that perhaps I am not constructing/exporting my async cache() function properly.

Answer 1

Upon further review, I don't actually understand why the author has implemented it the way he has. Why would you want to create an instance of localForage every single time you make an API call?
I've opted not to use a component and to only instantiate an instance of localForage once.
main.js
import localforage from 'localforage'
import memoryDriver from 'localforage-memoryStorageDriver'
import { setup } from 'axios-cache-adapter'
// Register the custom `memoryDriver` to `localforage`
localforage.defineDriver(memoryDriver)
// Create `localforage` instance
const localforageStore = localforage.createInstance({
// List of drivers used
driver: [
localforage.INDEXEDDB,
localforage.LOCALSTORAGE,
memoryDriver._driver
],
// Prefix all storage keys to prevent conflicts
name: 'my-cache'
})
Vue.prototype.$http = setup({
baseURL: 'https://my.api',
cache: {
maxAge: 2 * 60 * 1000, // set cache time to 2 minutes
exclude: { query: false }, // cache requests with query parameters
localforageStore // pass `localforage` store to `axios-cache-adapter`
}
})
the view
export default {
data() {
return {
userId: this.$route.params.id,
userData: ''
}
},
methods: {
loadClient(userId) {
const thisIns = this;
thisIns.$http.get('/client/find?id='+userId)
.then(async (response) => {
thisIns.userData = response.data.data[0]
})
.catch(function (error) {
console.log(error)
})
},
},
created() {
this.loadClient(this.userId)
},
}