Vue: executing two methods in specific order - vue.js

Question

I have a Vue application. I would like to retrieve entries (from a database) based on a userid. I have the following methods in Vue:
export default {
name: 'Entries',
data() {
return {
userid: null
};
},
methods: {
getEntries() {
this.getUserID();
console.log("userid getEntries: " + this.userid);
axios.get('/entries', this.userid)
.then((res) => {
this.entries = res.data;
console.log(this.entries);
})
.catch((error) => {
console.error(error);
});
},
getUserID() {
axios.get('/userid')
.then((res) => {
this.userid = res.data;
console.log("userid getUserId: " + this.userid );
})
.catch((error) => {
console.error(error);
});
},
},
created() {
this.getEntries();
}
};
Within the getEntries method, I'm immediately calling the getUserID function. I would assume this sets the variable userid to the value retrieved from the getUserID method.
Instead I get the following output in the browser console, in exactly this order:
userid getEntries: null
userid getUserId: user_a
Why does it print first the console output from the getEntries function? And why is this null if it first executes the getUserID method?
How could I change is so that the axios call /entries can pass the userid.

Answer 1

axios calls are async, if you need the userid populated before anything else is called, then you should populate before anything else is called, in mounted/created.
Then you can react to its change with a watcher. You could call getEntries when the getUserID call resolves but it's dirty and couples the two methods.
And don't forget to assign entries in data.
This will work:
export default {
name: 'Entries',
data() {
return {
userid: null,
entries: []
};
},
watch: {
userid (v) {
if (v) this.getEntries()
}
},
mounted() {
this.$nextTick(this.getUserID)
},
methods: {
getEntries() {
console.log("userid getEntries: " + this.userid);
axios.get('/entries', this.userid)
.then((res) => {
this.entries = res.data;
console.log(this.entries);
})
.catch((error) => {
console.error(error);
});
},
getUserID() {
axios.get('/userid')
.then((res) => {
this.userid = res.data;
console.log("userid getUserId: " + this.userid);
})
.catch((error) => {
console.error(error);
});
}
}
};
Using async/await
export default {
name: 'Entries',
data() {
return {
userid: null,
entries: []
};
},
watch: {
userid (v) {
if (v) this.getEntries()
}
},
mounted() {
this.$nextTick(this.getUserID)
},
methods: {
async getEntries() {
try {
const { data } = await axios.get('/entries', this.userid)
this.entries = data;
} catch (error) {
console.error(error);
}
},
async getUserID() {
try {
const { data } = await axios.get('/userid')
this.userid = data;
} catch (error) {
console.error(error);
}
}
}
};

Answer 2

Since getUserId is asynchronous, it doesn't return immediately. You therefore need to wait for it to return before continuing. This can be done using then but, nested Promises are a bit unpleasant to work with. A simpler option is to use async/await instead:
async getEntries() {
await this.getUserID();
console.log("userid getEntries: " + this.userid);
axios.get('/entries', this.userid)
.then((res) => {
this.entries = res.data;
console.log(this.entries);
})
.catch((error) => {
console.error(error);
});
},