Make an ajax call inside of a .map() - ajax

Question

I am upgrading jquery and saw that the "async: false" option has been deprecated. This makes sense and in 99.9% of cases I agree with the rationale, but I have a case where I think I really need it and I cannot for the life of me figure out how to make this work with a purely async ajax call no matter how I use promises or async/await.
My use case is in a Vue component and I have an array of contacts. What I need to do is map over the contacts and validate them. One such validation requires a quick check of email validity via a "check_email" ajax endpoint.
Once I validate (or not) the list, I then submit the list (if valid) or show error messages (if invalid).
My code is something like this
sendContacts: function() {
valid = this.validateContacts()
if (valid) {
// send the contacts
} else {
return // will display error messages on contacts objects
}
},
validateContacts: function() {
this.contacts = this.contacts.map((contact) => {
if (!contact.name) {
contact.validDetails.name = false
contact.valid = false
return contact
}
if (!contact.email) {
contact.validDetails.emailExists = false
contact.valid = false
return contact
}
if (!check_email(email)) { // THIS IS ASYNC NOW WHAT DO I DO
contact.valid = false
contact.validDetails.emailFormat = false
}
return contact
}
var validData = this.contacts.map(c => {
return c.valid
})
return !validData.includes(false)
}
function check_email(email) {
const url = `/api/v1/users/check-email?email=${email}`
let valid = false
$.ajax({
url: url,
type: 'POST',
async: false, // I can't do this anymore
headers: {
'X-CSRFToken': csrfToken
},
success: resp => {
valid = true
},
error: err => {
}
})
return valid
}
my data function:
data: function() {
return {
contacts: [this.initContact()],
showThanks: false,
emailError: false,
blankEmail: false,
blankName: false
}
},
methods: {
initContact: function() {
return {
name: null,
email: null,
title: null,
validDetails: this.initValidDetails(),
valid: true,
}
},
initValidDetails: function() {
return {
emailDomain: true,
emailExists: true,
emailFormat: true,
name: true
}
}
}
Again, I have tried async/await in every place I could think of and I cannot get this to validate properly and then perform correct logic regarding whether the send contacts function part of the function should fire. Please help!

Answer 1

Once any part of your validation is asynchronous, you must treat the entire thing as asynchronous. This includes when calling validateContacts in sendContacts.
First, you should change check_email to return Promise<bool>. It's usually a bad idea to include jQuery in a Vue project so let's use fetch instead (Axios being another popular alternative).
async function check_email(email) {
const params = new URLSearchParams({ email })
const res = await fetch(`/api/v1/users/check-email?${params}`, {
method: 'POST',
headers: {
'X-CSRFToken': csrfToken
}
})
return res.ok
}
As for your async validation logic, it's best to map your contacts to an array of promises and wait for them all with Promise.all.
async validateContacts () {
const validationPromises = this.contacts.map(async contact => {
if (!contact.name) {
return {
...contact,
valid: false,
validDetails: {
...contact.validDetails,
name: false
}
}
}
if (!contact.email) {
return {
...contact,
valid: false,
validDetails: {
...contact.validDetails,
emailExists: false
}
}
}
if (await check_email(contact.email)) { // await here
return {
...contact,
valid: false,
validDetails: {
...contact.validDetails,
emailFormat: false
}
}
}
return { ...contact, valid: true }
})
// now wait for all promises to resolve and check for any "false" values
this.contacts = await Promise.all(validationPromises)
return this.contacts.every(({ valid }) => valid)
}
As mentioned, now you need to treat this asynchronously in sendContacts
async sendContacts () {
if (await this.validateContacts()) {
// send the contacts
}
}