feat(ffi): add get_attached (#621)

crates/loro-ffi/src/container/counter.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use loro::{ContainerTrait, LoroResult};
 
 use crate::ContainerID;
@@ -14,6 +16,21 @@ impl LoroCounter {
         }
     }
 
+    /// Whether the container is attached to a document
+    ///
+    /// The edits on a detached container will not be persisted.
+    /// To attach the container to the document, please insert it into an attached container.
+    pub fn is_attached(&self) -> bool {
+        self.counter.is_attached()
+    }
+
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroCounter>> {
+        self.counter
+            .get_attached()
+            .map(|x| Arc::new(LoroCounter { counter: x }))
+    }
+
     /// Return container id of the Counter.
     pub fn id(&self) -> ContainerID {
         self.counter.id().into()

crates/loro-ffi/src/container/list.rs

@@ -26,6 +26,13 @@ impl LoroList {
         self.list.is_attached()
     }
 
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroList>> {
+        self.list
+            .get_attached()
+            .map(|x| Arc::new(LoroList { list: x }))
+    }
+
     /// Insert a value at the given position.
     pub fn insert(&self, pos: u32, v: Arc<dyn LoroValueLike>) -> LoroResult<()> {
         self.list.insert(pos as usize, v.as_loro_value())

crates/loro-ffi/src/container/map.rs

@@ -22,6 +22,13 @@ impl LoroMap {
         self.map.is_attached()
     }
 
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroMap>> {
+        self.map
+            .get_attached()
+            .map(|x| Arc::new(LoroMap { map: x }))
+    }
+
     /// Delete a key-value pair from the map.
     pub fn delete(&self, key: &str) -> LoroResult<()> {
         self.map.delete(key)

crates/loro-ffi/src/container/movable_list.rs

@@ -31,6 +31,13 @@ impl LoroMovableList {
         self.list.is_attached()
     }
 
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroMovableList>> {
+        self.list
+            .get_attached()
+            .map(|x| Arc::new(LoroMovableList { list: x }))
+    }
+
     /// Insert a value at the given position.
     pub fn insert(&self, pos: u32, v: Arc<dyn LoroValueLike>) -> LoroResult<()> {
         self.list.insert(pos as usize, v.as_loro_value())

crates/loro-ffi/src/container/text.rs

@@ -1,6 +1,6 @@
 use std::{fmt::Display, sync::Arc};
 
-use loro::{cursor::Side, LoroResult, PeerID, UpdateOptions, UpdateTimeoutError};
+use loro::{cursor::Side, ContainerTrait, LoroResult, PeerID, UpdateOptions, UpdateTimeoutError};
 use loro_internal::handler::TextDelta as InternalTextDelta;
 
 use crate::{ContainerID, LoroValue, LoroValueLike, TextDelta};
@@ -31,6 +31,13 @@ impl LoroText {
         self.text.is_attached()
     }
 
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroText>> {
+        self.text
+            .get_attached()
+            .map(|x| Arc::new(LoroText { text: x }))
+    }
+
     /// Get the [ContainerID]  of the text container.
     pub fn id(&self) -> ContainerID {
         self.text.id().into()

crates/loro-ffi/src/container/tree.rs

@@ -33,6 +33,13 @@ impl LoroTree {
         self.tree.is_attached()
     }
 
+    /// If a detached container is attached, this method will return its corresponding attached handler.
+    pub fn get_attached(&self) -> Option<Arc<LoroTree>> {
+        self.tree
+            .get_attached()
+            .map(|x| Arc::new(LoroTree { tree: x }))
+    }
+
     /// Create a new tree node and return the [`TreeID`].
     ///
     /// If the `parent` is `None`, the created node is the root of a tree.