refactor(api): use HTTP status codes to convey API call results

src/api.rs

@@ -19,10 +19,11 @@ use handlebars::Handlebars;
 use ldap3::{ldap_escape, LdapConn};
 use ldap3::exop::PasswordModify;
 use ldap3::result::LdapError;
+use rocket::http::Status;
 use rocket_contrib::json::Json;
 
 use rocket::post;
-use serde_derive::{Deserialize, Serialize};
+use serde_derive::Deserialize;
 use serde_json::json;
 
 use crate::context::Context;
@@ -34,18 +35,6 @@ pub struct PasswordData {
     new_password: String,
 }
 
-#[derive(Serialize)]
-enum Message {
-    InvalidCredentials,
-    ServerError,
-}
-
-#[derive(Serialize)]
-pub struct Response {
-    success: bool,
-    message: Option<Message>,
-}
-
 fn change_password(data: &Json<PasswordData>,
                    context: &rocket::State<Context>) -> Result<()> {
 
@@ -80,33 +69,23 @@ fn change_password(data: &Json<PasswordData>,
 
 #[post("/update", data = "<data>")]
 pub fn update(data: Json<PasswordData>,
-              context: rocket::State<Context>) -> Json<Response> {
-    Json(
+              context: rocket::State<Context>) -> Status {
     match change_password(&data, &context) {
-            Ok(_) => Response{
-                success: true,
-                message: None,
-            },
+        Ok(_) => Status::Accepted,
         Err(error) => {
             eprintln!("LDAP error: {}", error);
-                Response {
-                    success: false,
-                    message: Some(
             match error.downcast::<LdapError>().expect(
                 "No other error should occur here"
             ) {
                 LdapError::LdapResult{ result } => {
                     if result.rc == 49 {
-                                    Message::InvalidCredentials
+                        Status::Unauthorized
                     } else {
-                                    Message::ServerError
+                        Status::InternalServerError
                     }
                 },
-                            _ => Message::ServerError,
-                        }
-                    ),
+                _ => Status::InternalServerError,
             }
         },
     }
-    )
 }

src/static/webldappasswd.js

@@ -27,9 +27,8 @@ MODAL_STATES = {
   },
   "FetchError" : {
     button_disabled : false,
-    message : function(parameters) {
-      `An error occurred while contacting the server (${parameters.statusCode})`
-    },
+    message : "An error occurred while contacting the server",
+    icon_url : "cross.svg",
   },
   "ServerError" : {
     button_disabled : false,
@@ -43,7 +42,7 @@ MODAL_STATES = {
   },
 }
 
-function showModal(state_name, parameters) {
+function showModal(state_name) {
   const state = MODAL_STATES[state_name];
 
   const message = document.getElementById("message");
@@ -52,9 +51,7 @@ function showModal(state_name, parameters) {
   img.src = state.icon_url;
 
   const text = message.childNodes[1];
-  text.textContent = " " + (state.message instanceof Function
-                            ? state.message(parameters)
-                            : state.message);
+  text.textContent = " " + state.message;
 
   const button = document.getElementById("close_button");
   button.disabled = state.button_disabled;
@@ -97,17 +94,23 @@ function changePasswords() {
     method: "POST",
     body: JSON.stringify(query),
   }).then(response => {
-    if(response.status == 200) {
-      return response.json();
-    } else {
-      showModal("FetchError", { statusCode : response.status });
-    }
-  }).then(response => {
-      if(response.success) {
+    switch(response.status) {
+    case 202:
       showModal("Success");
-        clearFields();
-      } else {
-        showModal(response.message);
+      break;
+    case 401:
+      showModal("InvalidCredentials");
+      break;
+    case 500:
+      showModal("ServerError");
+      break;
+    default:
+      console.log("Unexpected status code: " + response.status);
+      showModal("FetchError");
+      break;
     }
-  });
+  }, error => {
+    console.log("Fetch error: " + error);
+    showModal("FetchError");
+  })
 }