passing list of string from apex controller to javascript->aura component

Question

I'm trying to pass a list of string from Apex controller to Javascript but it does not seem to work

Code I tried:

Apex class

 @AuraEnabled
 public static List<String> getGroups(){
     string names;
     List<String> Groupnames = new List<String>();
     Http http = new Http();
     HttpRequest request = new HttpRequest();
     request.setMethod('GET');
     request.setHeader('X-ChatWorkToken',key);
     request.setEndpoint('https://api.chatwork.com/v2/rooms');
     HttpResponse res = http.send(request);
     LIST<Object> arr = (LIST<Object>) JSON.deserializeUntyped(res.getBody());
     for(integer i = 0; i < arr.size(); i++){
         Map<String, Object> firstMap = (Map<String, Object>)arr[i];
         names = (String)firstMap.get('name');
         Groupnames.add(names);
     }
     return Groupnames;
 }

Javascript

listofgroup:function(component, event, helper){
    var action = component.get("c.getGroups");
    console.log('received',response);
    action.setCallback(this, function(response){
        //var state = response.getState();
        // if(state === 'SUCCESS'){
            var res = response.getReturnValue();
            for(var i = 0; i < res.length; i++){
                //set the values here
                component.set("v.lstGroup",response.getReturnValue());
            }
        }
    // }
    )
}

dont know where I'm going wrong

Answer 1

Looks like you have forgotten to actually call (enqueue) the action.

Like this:

action.setCallback(this, function(response){
  //your other stuff
});
//add here:
$A.enqueueAction(action);

In your callback, to use as a select list, process something like this:

let groupValues = [];
let res = response.getReturnValue();
res.forEach( (value)=>{
  groupValues.push({label:value,value:value});
});
component.set("v.lstGroup",groupValues);