Does Vue.JS work with AJAX http calls? - ajax

Question

I am trying to do the following from my HTML:
var vm = new Vue({
el: '#loginContent',
data: {
main_message: 'Login',
isLoggedIn: false,
loginError: '',
loginButton:'Login'
},
methods: {
onLogin: function() {
//this.$set(loginSubmit, 'Logging In...');
var data = {
email: $('#email').val(),
password: $('#password').val(),
};
$.ajax({
url: '/api/login',
data: data,
method: 'POST'
}).then(function (response) {
if(response.error) {
console.err("There was an error " + response.error);
this.loginError = 'Error';
} else {
//$('#loginBlock').attr("hidden",true);
console.log(response.user);
if(response.user) {
this.isLoggedIn = true;
} else {
this.loginError = 'User not found';
}
}
}).catch(function (err) {
console.error(err);
});
}
}
});
Basically user presses the login button, onLogin method is called that sends a post to my API. The post is working fine and I do get the response back in the .then() promise.
But, trying to do things like this.isLoggedIn = true; does not update my DOM with what I am expecting the HTML to do when the user logs in.
Could be that I am in some sort of background thread (sorry, mobile developer here) when I get the response in the promise and it can't find the "vm" instance?
Thanks

Answer 1

It is probably happening because your this is not pointing to correct scope, scope of this changes inside an $.ajax call, so you just have to do something like following:
methods: {
onLogin: function() {
//this.$set(loginSubmit, 'Logging In...');
var data = {
email: $('#email').val(),
password: $('#password').val(),
};
var that = this
$.ajax({
url: '/api/login',
data: data,
method: 'POST'
}).then(function (response) {
if(response.error) {
console.err("There was an error " + response.error);
that.loginError = 'Error';
} else {
//$('#loginBlock').attr("hidden",true);
console.log(response.user);
if(response.user) {
that.isLoggedIn = true;
} else {
that.loginError = 'User not found';
}
}
}).catch(function (err) {
console.error(err);
});
}
}

Answer 2

I would propose another method use ES6 Arrow Functions like '=>'. It is simple and do not need extra variable.Like following:
$.ajax({
url: '/api/login',
data: data,
method: 'POST'
}).then((response) => {
if(response.error) {
console.err("There was an error " + response.error);
this.loginError = 'Error';
} else {
//$('#loginBlock').attr("hidden",true);
console.log(response.user);
if(response.user) {
this.isLoggedIn = true;
} else {
this.loginError = 'User not found';
}
}
}).catch(function (err) {
console.error(err);
});

Answer 3

You might want to take a look at axios. I used $.ajax and got it working, but found axios and prefer axios over the ajax library.