App uses backend to created prices on slint

project/src/app.rs

@@ -1,6 +1,10 @@
 // Libraries
 slint::include_modules!();
+use slint::{ModelRc, SharedString, VecModel};
 use std::io::Result;
+use std::rc::Rc;
+
+use super::Backend;
 
 // Macros
 macro_rules! map_err {
@@ -11,7 +15,8 @@ macro_rules! map_err {
 
 // Structures
 pub struct App {
-    app: Prorater,
+    app: Rc<Prorater>,
+    backend: Rc<Backend>,
 }
 
 // Implementations
@@ -23,12 +28,28 @@ impl App {
     /// ```rs
     /// let app = App::new()?;
     /// ```
-    pub fn new() -> Result<Self> {
+    pub fn new(backend: Rc<Backend>) -> Result<Self> {
         // Creating our new app
         let app = map_err!(Prorater::new())?;
 
+        // Setting the Membership Options
+        let memberships = {
+            let vec_model: VecModel<SharedString> = {
+                let result = VecModel::from(vec![SharedString::from("Select One...")]);
+                for i in backend.get_memberships() {
+                    result.push(SharedString::from(i));
+                }
+                result
+            };
+            ModelRc::new(vec_model)
+        };
+        app.set_membership_names(memberships.clone());
+
+        // Turning the App into an Rc
+        let app = Rc::new(app);
+
         // Returning Self
-        Ok(Self { app })
+        Ok(Self { app, backend })
     }
 
     // Functions
@@ -39,6 +60,20 @@ impl App {
     /// app.start()?;
     /// ```
     pub fn start(&self) -> Result<()> {
+        // Creating an Rc of our App
+        let app = Rc::clone(&self.app);
+
+        // Setting the on_submit function
+        self.app.on_on_calculate(move || {
+            // Getting the prices of the stuff
+            let current_membership = app.get_current_membership();
+            let new_membership = app.get_new_membership();
+
+            // DEBUG
+            println!("Current Membership: {}", current_membership);
+            println!("New Membership: {}", new_membership);
+        });
+
         // Starting our application
         map_err!(self.app.run())?;