Merge pull request 'Implement Associated Type for Keys' (#3) from try-associated-type into main

Reviewed-on: #3

src/admin_examples/empty_repository.rs

@@ -8,6 +8,16 @@ impl Repository {}
 
 #[async_trait]
 impl AdminRepository for Repository {
+    type Key = i64;
+
+    fn key_from_string(&self, s: String) -> Option<Self::Key> {
+        if let Ok(i) = s.parse::<i64>() {
+            Some(i)
+        } else {
+            None
+        }
+    }
+
     async fn info(&self, _: &RepositoryContext) -> RepositoryInfo {
         RepoInfo {
             name: "My Empty Repository",
@@ -33,7 +43,7 @@ impl AdminRepository for Repository {
     }
 
     // GET single item.
-    async fn get(&self, model: &RepositoryContext, id: LookupKey) -> Option<RepositoryItem> {
+    async fn get(&self, model: &RepositoryContext, id: &Self::Key) -> Option<RepositoryItem> {
         None
     }
 
@@ -41,7 +51,7 @@ impl AdminRepository for Repository {
     async fn update(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
         None
@@ -51,14 +61,14 @@ impl AdminRepository for Repository {
     async fn replace(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
         None
     }
 
     // DELETE single item.
-    async fn delete(&mut self, _: &RepositoryContext, id: LookupKey) -> Option<Value> {
+    async fn delete(&mut self, _: &RepositoryContext, id: &Self::Key) -> Option<Value> {
         None
     }
 }

src/admin_examples/static_repository.rs

@@ -36,6 +36,16 @@ impl MyStaticRepository {
 
 #[async_trait]
 impl AdminRepository for MyStaticRepository {
+    type Key = i64;
+
+    fn key_from_string(&self, s: String) -> Option<Self::Key> {
+        if let Ok(i) = s.parse::<i64>() {
+            Some(i)
+        } else {
+            None
+        }
+    }
+
     async fn info(&self, _: &RepositoryContext) -> RepositoryInfo {
         RepoInfo {
             name: "My Static Repository",
@@ -48,15 +58,11 @@ impl AdminRepository for MyStaticRepository {
         //.set_widget("name", Widget::textarea().options(&[("disabled", "true")]))
     }
 
-    async fn get(&self, model: &RepositoryContext, id: LookupKey) -> Option<RepositoryItem> {
-        if let LookupKey::Integer(id) = id {
-            let item = self.content.get(id - 1).cloned().unwrap();
-            let id = item.get("id").unwrap();
-            Some(model.build_item(&*id.to_string(), item))
-        } else {
-            warn!("Got non-integer lookup key: {}", id);
-            None
-        }
+    async fn get(&self, model: &RepositoryContext, id: &Self::Key) -> Option<RepositoryItem> {
+        let id = *id as usize;
+        let item = self.content.get(id - 1).cloned().unwrap();
+        let id = item.get("id").unwrap();
+        Some(model.build_item(&*id.to_string(), item))
     }
 
     async fn list(&self, model: &RepositoryContext) -> RepositoryList {
@@ -94,7 +100,7 @@ impl AdminRepository for MyStaticRepository {
     async fn update(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
         debug!("I would now update: {}, {}", id, data);
@@ -102,10 +108,7 @@ impl AdminRepository for MyStaticRepository {
         // First, find the index of the item to update
         let item_index = self.content.iter().position(|item| {
             if let Some(item_id) = item.get("id") {
-                match id {
-                    LookupKey::Integer(i) => item_id == &i,
-                    LookupKey::String(ref s) => item_id == s,
-                }
+                item_id == id
             } else {
                 false
             }
@@ -127,21 +130,18 @@ impl AdminRepository for MyStaticRepository {
     async fn replace(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
         self.update(model, id, data).await
     }
 
-    async fn delete(&mut self, _: &RepositoryContext, id: LookupKey) -> Option<Value> {
+    async fn delete(&mut self, _: &RepositoryContext, id: &Self::Key) -> Option<Value> {
         debug!("Would delete: {}", id);
 
         let item_index = self.content.iter().position(|item| {
             if let Some(item_id) = item.get("id") {
-                match id {
-                    LookupKey::Integer(i) => item_id == &i,
-                    LookupKey::String(ref s) => item_id == s,
-                }
+                item_id == id
             } else {
                 false
             }

src/admin_examples/user_repository.rs

@@ -19,6 +19,16 @@ impl UserRepository {
 
 #[async_trait]
 impl AdminRepository for UserRepository {
+    type Key = i64;
+
+    fn key_from_string(&self, s: String) -> Option<Self::Key> {
+        if let Ok(i) = s.parse::<i64>() {
+            Some(i)
+        } else {
+            None
+        }
+    }
+
     async fn info(&self, _: &RepositoryContext) -> RepositoryInfo {
         RepoInfo {
             name: "User",
@@ -29,25 +39,24 @@ impl AdminRepository for UserRepository {
         .into()
     }
 
-    async fn get(&self, model: &RepositoryContext, id: LookupKey) -> Option<RepositoryItem> {
-        if let LookupKey::Integer(id) = id {
-            let id: i32 = id as i32; // use try_into() instead.
-            let get_user = entity::User::find_by_id(id).one(&self.connection).await;
-            match get_user {
-                Ok(get_user) => {
-                    if let Some(user) = get_user {
-                        let id = user.id.to_string();
-                        match serde_json::to_value(&user) {
-                            Ok(item) => {
-                                return Some(model.build_item(&*id, item));
-                            }
-                            Err(_) => return None,
+    async fn get(&self, model: &RepositoryContext, id: &Self::Key) -> Option<RepositoryItem> {
+        let id: i32 = *id as i32; // use try_into() instead.
+        let get_user = entity::User::find_by_id(id).one(&self.connection).await;
+        match get_user {
+            Ok(get_user) => {
+                if let Some(user) = get_user {
+                    let id = user.id.to_string();
+                    match serde_json::to_value(&user) {
+                        Ok(item) => {
+                            return Some(model.build_item(&*id, item));
                         }
+                        Err(_) => return None,
                     }
                 }
-                Err(_) => return None,
             }
+            Err(_) => return None,
         }
+
         None
     }
 
@@ -94,58 +103,56 @@ impl AdminRepository for UserRepository {
     async fn update(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
-        if let LookupKey::Integer(id) = id {
-            let id: i32 = id as i32; // use try_into() instead.
-            let user: Option<entity::user::Model> = entity::User::find_by_id(id)
-                .one(&self.connection)
-                .await
-                .unwrap();
-            let mut user: entity::user::ActiveModel = user.unwrap().into();
+        let id: i32 = *id as i32;
+        let user: Option<entity::user::Model> = entity::User::find_by_id(id)
+            .one(&self.connection)
+            .await
+            .unwrap();
+        let mut user: entity::user::ActiveModel = user.unwrap().into();
 
-            // change values
-            if let Some(value) = data.get("username") {
-                if let Some(value) = value.as_str() {
-                    user.username = Set(value.to_owned());
-                }
-            }
-
-            if let Some(value) = data.get("description") {
-                user.description = Set(value.as_str().map(|s| s.to_owned()));
-            }
-
-            // update
-            if let Ok(user) = user.update(&self.connection).await {
-                let id = user.id.to_string();
-                return Some(model.build_item(&*id, serde_json::to_value(&user).unwrap()));
+        // change values
+        if let Some(value) = data.get("username") {
+            if let Some(value) = value.as_str() {
+                user.username = Set(value.to_owned());
             }
         }
+
+        if let Some(value) = data.get("description") {
+            user.description = Set(value.as_str().map(|s| s.to_owned()));
+        }
+
+        // update
+        if let Ok(user) = user.update(&self.connection).await {
+            let id = user.id.to_string();
+            return Some(model.build_item(&*id, serde_json::to_value(&user).unwrap()));
+        }
+
         None
     }
 
     async fn replace(
         &mut self,
         model: &RepositoryContext,
-        id: LookupKey,
+        id: &Self::Key,
         data: Value,
     ) -> Option<RepositoryItem> {
         self.update(model, id, data).await
     }
 
-    async fn delete(&mut self, _: &RepositoryContext, id: LookupKey) -> Option<Value> {
-        if let LookupKey::Integer(id) = id {
-            let id: i32 = id as i32; // use try_into() instead.
-            let user: Option<entity::user::Model> = entity::User::find_by_id(id)
-                .one(&self.connection)
-                .await
-                .unwrap();
-            if let Some(user) = user {
-                let delete_result = user.delete(&self.connection).await.unwrap();
-                debug!("deleted rows: {}", delete_result.rows_affected);
-            }
+    async fn delete(&mut self, _: &RepositoryContext, id: &Self::Key) -> Option<Value> {
+        let id: i32 = *id as i32;
+        let user: Option<entity::user::Model> = entity::User::find_by_id(id)
+            .one(&self.connection)
+            .await
+            .unwrap();
+        if let Some(user) = user {
+            let delete_result = user.delete(&self.connection).await.unwrap();
+            debug!("deleted rows: {}", delete_result.rows_affected);
         }
+
         None
     }
 }

src/bin/generic_trait_type_erasure.rs

@@ -0,0 +1,142 @@
+use std::any::Any;
+use std::collections::HashMap;
+use std::fmt::Debug;
+
+// Define the Key trait with Any and Debug for type erasure and debugging
+pub trait Key: Any + Debug {
+    fn as_any(&self) -> &dyn Any;
+}
+
+// Implement Key for i32
+impl Key for i32 {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}
+
+// Implement Key for String
+impl Key for String {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}
+
+// Implement From<String> for i32
+impl From<String> for Box<dyn Key> {
+    fn from(s: String) -> Box<dyn Key> {
+        if let Ok(i) = s.parse::<i32>() {
+            Box::new(i)
+        } else {
+            Box::new(s)
+        }
+    }
+}
+
+// Define the Repository trait with an associated type Key
+pub trait Repository {
+    type Key: Key;
+    fn get_entry(&self, key: &Self::Key) -> String;
+}
+
+// Define a helper trait for dynamic dispatch
+pub trait DynRepository {
+    fn get_entry(&self, key: &dyn Key) -> String;
+}
+
+// Define a type-erased wrapper for Repository
+pub struct RepositoryWrapper<T: Repository> {
+    inner: T,
+}
+
+impl<T: Repository> RepositoryWrapper<T> {
+    pub fn new(inner: T) -> Self {
+        Self { inner }
+    }
+}
+
+impl<T: Repository> DynRepository for RepositoryWrapper<T> {
+    fn get_entry(&self, key: &dyn Key) -> String {
+        if let Some(key) = key.as_any().downcast_ref::<T::Key>() {
+            self.inner.get_entry(key)
+        } else {
+            "Invalid Key Type".to_string()
+        }
+    }
+}
+
+// Implement the Repository trait for IntRepository
+pub struct IntRepository {
+    data: HashMap<i32, String>,
+}
+
+impl IntRepository {
+    pub fn new() -> Self {
+        let mut data = HashMap::new();
+        data.insert(1, "IntEntry1".to_string());
+        data.insert(2, "IntEntry2".to_string());
+        Self { data }
+    }
+}
+
+impl Repository for IntRepository {
+    type Key = i32;
+
+    fn get_entry(&self, key: &Self::Key) -> String {
+        self.data
+            .get(key)
+            .unwrap_or(&"Not Found".to_string())
+            .clone()
+    }
+}
+
+// Implement the Repository trait for StringRepository
+pub struct StringRepository {
+    data: HashMap<String, String>,
+}
+
+impl StringRepository {
+    pub fn new() -> Self {
+        let mut data = HashMap::new();
+        data.insert("one".to_string(), "StringEntry1".to_string());
+        data.insert("two".to_string(), "StringEntry2".to_string());
+        Self { data }
+    }
+}
+
+impl Repository for StringRepository {
+    type Key = String;
+
+    fn get_entry(&self, key: &Self::Key) -> String {
+        self.data
+            .get(key)
+            .unwrap_or(&"Not Found".to_string())
+            .clone()
+    }
+}
+
+fn main() {
+    let int_repo = IntRepository::new();
+    let string_repo = StringRepository::new();
+
+    let repositories: Vec<Box<dyn DynRepository>> = vec![
+        Box::new(RepositoryWrapper::new(int_repo)),
+        Box::new(RepositoryWrapper::new(string_repo)),
+    ];
+
+    // Creating keys from strings using the From<String> implementation
+    let keys: Vec<Box<dyn Key>> = vec![
+        Box::new(1_i32),
+        Box::new("one".to_string()),
+        Box::new(99_i32),                // non-existing int key
+        Box::new("unknown".to_string()), // non-existing string key
+        Box::from("123".to_string()),    // i32 key from string
+        Box::from("hello".to_string()),  // String key from string
+    ];
+
+    for key in keys {
+        for repo in &repositories {
+            let result = repo.get_entry(key.as_ref());
+            println!("Result: {}", result);
+        }
+    }
+}