Tried adding comboBox content

client/app/src/main/java/main/OptionController.java

@@ -1,16 +1,24 @@
 package main;
 
 import com.jfoenix.controls.*;
+import helper.HttpRequestException;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Node;
 import javafx.scene.Scene;
 import javafx.scene.control.Label;
+import javafx.scene.layout.GridPane;
 import javafx.stage.Modality;
 import javafx.stage.Stage;
+import res.DataController;
+import res.User;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Objects;
 
 public class OptionController {
@@ -27,9 +35,26 @@ public class OptionController {
     public Label labelError;
     @FXML
     public JFXComboBox<String> userCmb;
+    @FXML
+    public GridPane mainGrid;
 
     @FXML
     public void initialize(){
+        DataController dataController = new DataController();
+        List<User> users;
+        try{
+           users = dataController.getAllUser();
+        } catch (HttpRequestException e){
+           users = new ArrayList<>();
+        }
+
+        ObservableList<String> observableUserList = FXCollections.observableArrayList();
+        for (User user: users) {
+            observableUserList.add(user.getLogin());
+        }
+        JFXComboBox comboBox = new JFXComboBox(observableUserList);
+        comboBox.getStyleClass().add("comboBox");
+        mainGrid.add(comboBox, 2,2);
 
     }
 

client/app/src/main/resources/main/option-view.fxml

@@ -3,12 +3,12 @@
 <?import javafx.scene.control.*?>
 <?import javafx.scene.layout.*?>
 <?import com.jfoenix.controls.*?>
-<?import javafx.collections.FXCollections?>
 
 <GridPane xmlns="http://javafx.com/javafx"
           xmlns:fx="http://javafx.com/fxml"
           fx:controller="main.OptionController"
-          prefHeight="400.0" prefWidth="600.0">
+          prefHeight="400.0" prefWidth="600.0"
+fx:id="mainGrid">
 
     <columnConstraints>
         <ColumnConstraints minWidth="100"/>
@@ -33,13 +33,6 @@
     <Label styleClass="mainLabel" GridPane.columnIndex="2" GridPane.halignment="CENTER" >Einstellungen</Label>
 
     <Label GridPane.columnIndex="1" GridPane.rowIndex="2" GridPane.halignment="CENTER">User:</Label>
-    <JFXComboBox styleClass="comboBox" fx:id="userCmb" GridPane.columnIndex="2" GridPane.rowIndex="2">
-        <items>
-            <FXCollections fx:factory="observableArrayList">
-
-            </FXCollections>
-        </items>
-    </JFXComboBox>
 
     <JFXButton styleClass="userBtn" fx:id="updateUserBtn" GridPane.columnIndex="1" GridPane.columnSpan="3"
                GridPane.rowIndex="4" GridPane.halignment="CENTER" onAction="#onUpdateBtnClick">User bearbeiten</JFXButton>

client/data/src/main/java/res/DataController.java

@@ -138,7 +138,7 @@ public class DataController {
      * User *
      ********/
 
-    public List<User> getUser() throws HttpRequestException {
+    public List<User> getAllUser() throws HttpRequestException {
         String userJSON = sendBasicHttpRequest(
                 ALL_USER_ENDPOINT,
                 "",