I have an issue when I call my webservice in Angular2. My variable this.arc
is always empty because the function get()
is asynchronous and it return directly the variable before webservice's response.
I don't know how to handle this. I saw some informations about defer
but i think is not the best way.
Thanks !
getArcs (lat,lng) {
var url = "http://localhost:8081/api/v1/arcs?lat="+lat+"&lng="+lng;
this.arcs = [];
/*var options = new RequestOptions({
headers: new Headers({
'Content-Type': 'application/json;charset=UTF-8'
})
});*/
this.http.get(url)
.subscribe(
(data: any) => {
JSON.parse(data._body).forEach(arc => {
//console.log(new Arc(arc));
this.arcs.push(new Arc(arc)); //add arcs
});
console.log("send");
},
error => {
console.log("error during http request");
}
);
return this.arcs;
}
---- EDIT----
I think the problem is at the call of the function :
public getData (lat,lng) {
var closedArc = this.arcService.getArcs(lat,lng);
console.log(closedArc);
//this.showArc(closedArc);
}
Since your really need data in your getData()
function, you can move subscribe logic there, and let getArcs()
return an Observable. This is a good practice - let services return Observables and subscribe to them when you need data.
getArcs(lat, lng) {
var url = "http://localhost:8081/api/v1/arcs?lat=" + lat + "&lng=" + lng;
return this.http
.get(url)
.map(response => response.json()) // response has builtin method to parse json.
.map(arc => {
return new Arc(arc);
})
}
public getData(lat, lng) {
var closedArc;
this.arcService
.getArcs(lat, lng)
.subscribe(
arcs => closedArc = arcs, // success
error => console.log("error during http request"), // error
() => this.showArc(closedArc) // complete
)
}
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