Angular 4 wait till http.get execute to continue - json

Question

I'm creating a new register form an app with Ionic and using ASP.Net(C#) as my API.
I want to check if user exists when the input blur event is activate.
The problem is that my code isn't waiting till the server returns a value to continue.
What am I doing wrong? Is there a way to do that?
THIS IS MY API CODE:
[HttpGet]
public JsonResult verifyEmail(string email)
{
var result = Domain.Repository.UserController.Find(email:email);
if (result != null)
{
return Json(new { erro = true, message = "Email already registered!" }, JsonRequestBehavior.AllowGet);
}
else
{
return Json(new { erro=false,message = "Email is valid!" },JsonRequestBehavior.AllowGet);
}
}
I CREATED A PROVIDER TO MAKE THE HTTP REQUEST(authProvider):
getData(data,func)
{
return new Promise( (resolve,reject)=>{
this.http.get(apiUrl+func, {params:data})
.subscribe(
res=>{
resolve(res.json());
},
async (err)=>{
reject(err);
});
});
}
AND HERE IS MY register.ts code:
validate()
{
let validEmail;
validEmail= this.checkEmail();// I WANT THAT the "validEmail" receives returned value before continue.
return true;
}
AND THE LAST THING IS MY FUNCTION THAT WILL CALL THE PROVIDER:
checkEmail()
{
return this.authService.getData({email:this.model.email},"Account/verifyEmail").then((result)=>{
let response = <any>{};
response=result;
if(response.erro)
{
return response.message
}else
{
return true
}
},(err)=>{
this.toastService.presentToast("ERROR:"+err,"bottom",undefined,"toast-error");
});
}
Thanks in advance..

Answer 1

getData(data,func)
{
this.http.get(apiUrl+func, {params:data})
.map(res => {
return res.json();
})
.toPromise();
}
or with async/await
async getData(data,func)
{
let result = await this.http.get(apiUrl+func, {params:data})
.toPromise();
return result.json();
}
Now for the validate function:
async validate()
{
let validEmail;
await this.checkEmail();
return true;
}
Point is you cant jump from a sync function to an async or vice versa.
Validate needs to return a promise/observable because it is executes asynchronous functions.