Add an error management in db module

backend/Cargo.toml

@@ -10,10 +10,10 @@ actix-rt = "1"
 actix-files = "0.2"
 serde = { version = "1.0", features = ["derive"] }
 listenfd = "0.3" # To watch file modifications and automatically launch a build process (only used in dev/debug).
-ron = "0.5" # Rust object notation, to load configuration files.
+ron = "0.6" # Rust object notation, to load configuration files.
 itertools = "0.9"
 
-r2d2_sqlite = "0.15" # Connection pool with rusqlite (SQLite access).
+r2d2_sqlite = "0.16" # Connection pool with rusqlite (SQLite access).
 r2d2 = "0.8"
 
 futures = "0.3" # Needed by askam with the feature 'with-actix-web'.
@@ -21,11 +21,10 @@ futures = "0.3" # Needed by askam with the feature 'with-actix-web'.
 common = { path = "../common" }
 
 [dependencies.rusqlite]
-version = "0.22"
+version = "0.23"
 features = ["bundled"]
 
 # Template system.
 [dependencies.askama]
 version = "0.9"
 features = ["with-actix-web"]
-

backend/src/db.rs

@@ -11,6 +11,12 @@ use std::fs;
 use r2d2_sqlite::SqliteConnectionManager;
 use r2d2::Pool;
 
+#[derive(Debug)]
+pub enum DbError {
+    SqliteError(rusqlite::Error),
+    R2d2Error(r2d2::Error),
+    UnsupportedVersion(i32),
+}
 
 use super::consts;
 
@@ -26,8 +32,20 @@ pub struct Recipe {
     pub id: i32,
 }
 
+impl std::convert::From<rusqlite::Error> for DbError  {
+    fn from(error: rusqlite::Error) -> Self {
+        DbError::SqliteError(error)
+    }
+}
+
+impl std::convert::From<r2d2::Error> for DbError  {
+    fn from(error: r2d2::Error) -> Self {
+        DbError::R2d2Error(error)
+    }
+}
+
 impl Connection {
-    pub fn new() -> Connection {
+    pub fn new() -> Result<Connection, DbError> {
 
         let data_dir = Path::new(consts::DB_DIRECTORY);
 
@@ -39,59 +57,83 @@ impl Connection {
         let pool = r2d2::Pool::new(manager).unwrap();
 
         let connection = Connection { pool };
-        connection.create_or_update();
-        connection
+        connection.create_or_update()?;
+        Ok(connection)
     }
 
-    fn create_or_update(self: &Self) {
+    /*
+     * Called after the connection has been established for creating or updating the database.
+     * The 'Version' table tracks the current state of the database.
+     */
+    fn create_or_update(self: &Self) -> Result<(), DbError> {
         // let connection = Connection::new();
         // let mut stmt = connection.sqlite_con.prepare("SELECT * FROM versions ORDER BY date").unwrap();
-        // let mut stmt = connection.sqlite_con..prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='versions'").unwrap();
+        // let mut stmt = connection.sqlite_con.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='versions'").unwrap();
 
         // Check the Database version.
-        let con = self.pool.get().unwrap();
+        let mut con = self.pool.get()?;
+        let tx = con.transaction()?;
 
-        let version = {
-            match
-                con.query_row(
+        let mut version = {
+            match tx.query_row(
                     "SELECT [name] FROM [sqlite_master] WHERE [type] = 'table' AND [name] = 'Version'",
-                    rusqlite::NO_PARAMS,
-                    |row| row.get::<usize, String>(0)
-                ) {
-
-                Ok(_) => con.query_row("SELECT [version] FROM [Version]", rusqlite::NO_PARAMS, |row| row.get(0)).unwrap_or_default(),
+                        rusqlite::NO_PARAMS,
+                        |row| row.get::<usize, String>(0)
+                    ) {
+                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", rusqlite::NO_PARAMS, |row| row.get(0)).unwrap_or_default(),
                 Err(_) => 0
             }
         };
 
+        while Connection::update_to_next_version(version, &tx)? {
+            version += 1;
+        }
+
+        tx.commit()?;
+
+        Ok(())
+    }
+
+    fn update_to_next_version(version: i32, tx: &rusqlite::Transaction) -> Result<bool, DbError> {
         match version {
             0 => {
                 println!("Update to version 1...");
-                con.execute(
+
+                // Initial structure.
+                tx.execute_batch(
                     "
                     CREATE TABLE [Version] (
                         [id] INTEGER PRIMARY KEY,
-                        [version] INTEGER NOT NULL,
+                        [version] INTEGER NOT NULL UNIQUE,
                         [datetime] INTEGER DATETIME
-                    )
-                    ",
-                    rusqlite::NO_PARAMS
-                );
-                con.execute(
-                    "
+                    );
+
                     CREATE TABLE [Recipe] (
                         [id] INTEGER PRIMARY KEY,
                         [title] INTEGER NOT NULL,
                         [description] INTEGER DATETIME
-                    )
+                    );
+                    "
+                )?;
+
+                /*
+                tx.execute(
+                    "
+                    INSERT INTO Version
                     ",
                     rusqlite::NO_PARAMS
-                );
-                ()
+                );*/
+
+                Ok(true)
             }
+
+            // Current version.
+            1 =>
+                Ok(false),
+
             v =>
-                panic!("Unsupported database version: {}", v)
-        };
+                Err(DbError::UnsupportedVersion(v)),
+        }
     }
 
     pub fn get_all_recipes() {

backend/src/main.rs

@@ -39,7 +39,6 @@ async fn home_page(req: HttpRequest) -> impl Responder {
 
 #[get("/recipe/view/{id}")]
 async fn view_page(req: HttpRequest, path: web::Path<(i32,)>) -> impl Responder {
-    panic!("ERROR");
     ViewRecipeTemplate { recipes: vec![ db::Recipe { title: String::from("Saumon en croûte feuilletée"), id: 1 }, db::Recipe { title: String::from("Croissant au jambon"), id: 2 } ], current_recipe: db::Recipe { title: String::from("Saumon en croûte feuilletée"), id: 1 } }
 }
 
@@ -108,7 +107,10 @@ fn process_args() -> bool {
         print_usage();
         return true
     } else if args.iter().any(|arg| arg == "--test") {
-        let db_connection = db::Connection::new();
+        match db::Connection::new() {
+            Ok(_) => (),
+            Err(error) => println!("Error: {:?}", error)
+        }
         return true
     }