Can get the list of friends of another user

src/data/http_request_handler.rs

@@ -379,6 +379,11 @@ impl HttpRequestHandler {
         self.curr_user_id.clone()
     }
 
+    /// Get current user ID, return invalid user id value if there is none
+    pub fn user_id_or_invalid(&self) -> UserID {
+        self.user_id_opt().unwrap_or(UserID::invalid())
+    }
+
     /// Get an email included in the request
     pub fn post_email(&mut self, name: &str) -> ResultBoxError<String> {
         let mail = self.post_string(name)?;