Added basic create_action_client function

Author: esteve

examples/minimal_action_client_server/Cargo.toml

@@ -22,5 +22,5 @@ version = "0.3"
 [dependencies.rosidl_runtime_rs]
 version = "0.3"
 
-[dependencies.action_msgs]
+[dependencies.example_interfaces]
 version = "*"

examples/minimal_action_client_server/package.xml

@@ -14,11 +14,11 @@
 
   <build_depend>rclrs</build_depend>
   <build_depend>rosidl_runtime_rs</build_depend>
-  <build_depend>action_msgs</build_depend>
+  <build_depend>example_interfaces</build_depend>
 
   <exec_depend>rclrs</exec_depend>
   <exec_depend>rosidl_runtime_rs</exec_depend>
-  <exec_depend>action_msgs</exec_depend>
+  <exec_depend>example_interfaces</exec_depend>
 
   <export>
     <build_type>ament_cargo</build_type>

examples/minimal_action_client_server/src/minimal_action_client.rs

@@ -5,7 +5,9 @@ use anyhow::{Error, Result};
 fn main() -> Result<(), Error> {
     let context = rclrs::Context::new(env::args())?;
 
-    let _node = rclrs::create_node(&context, "minimal_action_client")?;
+    let mut node = rclrs::create_node(&context, "minimal_client")?;
+
+    let _client = node.create_action_client::<example_interfaces::action::Fibonacci>("fibonacci")?;
 
     Ok(())
 }

rclrs/src/action.rs

@@ -0,0 +1,28 @@
+use crate::{rcl_bindings::*, RclrsError};
+use std::sync::{Arc, Mutex, MutexGuard};
+
+use std::marker::PhantomData;
+
+pub struct ActionClient<T>
+where
+    T: rosidl_runtime_rs::Action,
+{
+    _marker: PhantomData<T>,
+}
+
+impl<T> ActionClient<T>
+where
+    T: rosidl_runtime_rs::Action,
+{
+    /// Creates a new action client.
+    pub(crate) fn new(rcl_node_mtx: Arc<Mutex<rcl_node_t>>, topic: &str) -> Result<Self, RclrsError>
+    // This uses pub(crate) visibility to avoid instantiating this struct outside
+    // [`Node::create_client`], see the struct's documentation for the rationale
+    where
+        T: rosidl_runtime_rs::Action,
+    {
+        Ok(Self {
+            _marker: Default::default(),
+        })
+    }
+}

rclrs/src/lib.rs

@@ -5,6 +5,7 @@
 //!
 //! [1]: https://github.com/ros2-rust/ros2_rust/blob/main/README.md
 
+mod action;
 mod arguments;
 mod client;
 mod context;
@@ -25,6 +26,7 @@ pub mod dynamic_message;
 
 use std::time::Duration;
 
+pub use action::*;
 pub use arguments::*;
 pub use client::*;
 pub use context::*;

rclrs/src/node.rs

@@ -13,9 +13,9 @@ pub use self::builder::*;
 pub use self::graph::*;
 use crate::rcl_bindings::*;
 use crate::{
-    Client, ClientBase, Context, GuardCondition, ParameterOverrideMap, Publisher, QoSProfile,
-    RclrsError, Service, ServiceBase, Subscription, SubscriptionBase, SubscriptionCallback,
-    ToResult,
+    ActionClient, Client, ClientBase, Context, GuardCondition, ParameterOverrideMap, Publisher,
+    QoSProfile, RclrsError, Service, ServiceBase, Subscription, SubscriptionBase,
+    SubscriptionCallback, ToResult,
 };
 
 impl Drop for rcl_node_t {
@@ -190,6 +190,26 @@ impl Node {
         Ok(client)
     }
 
+    /// Creates a [`Client`][1].
+    ///
+    /// [1]: crate::ActionClient
+    // TODO: make action client's lifetime depend on node's lifetime
+    pub fn create_action_client<T>(
+        &mut self,
+        topic: &str,
+    ) -> Result<Arc<ActionClient<T>>, RclrsError>
+    where
+        T: rosidl_runtime_rs::Action,
+    {
+        let client = Arc::new(ActionClient::<T>::new(
+            Arc::clone(&self.rcl_node_mtx),
+            topic,
+        )?);
+        // self.clients
+        //     .push(Arc::downgrade(&client) as Weak<dyn ClientBase>);
+        Ok(client)
+    }
+
     /// Creates a [`GuardCondition`][1] with no callback.
     ///
     /// A weak pointer to the `GuardCondition` is stored within this node.

rosidl_generator_rs/resource/action.rs.em

@@ -35,3 +35,20 @@ TEMPLATE(
     get_idiomatic_rs_type=get_idiomatic_rs_type,
     constant_value_to_rs=constant_value_to_rs)
 }@
+
+@[for subfolder, action_spec in action_specs]
+
+@{
+type_name = action_spec.namespaced_type.name
+}@
+
+  // Corresponds to @(package_name)__@(subfolder)__@(type_name)
+  pub struct @(type_name);
+
+  impl rosidl_runtime_rs::Action for @(type_name) {
+    type Goal = crate::@(subfolder)::rmw::@(type_name)_Goal;
+    type Result = crate::@(subfolder)::rmw::@(type_name)_Result;
+    type Feedback = crate::@(subfolder)::rmw::@(type_name)_Feedback;
+  }
+
+@[end for]

rosidl_generator_rs/resource/lib.rs.em

@@ -7,3 +7,7 @@ pub mod msg;
 @[if len(srv_specs) > 0]@
 pub mod srv;
 @[end if]@
+
+@[if len(action_specs) > 0]@
+pub mod action;
+@[end if]@

rosidl_runtime_rs/src/lib.rs

@@ -9,4 +9,4 @@ mod string;
 pub use string::{BoundedString, BoundedWString, String, StringExceedsBoundsError, WString};
 
 mod traits;
-pub use traits::{Message, RmwMessage, SequenceAlloc, Service};
+pub use traits::{Action, Message, RmwMessage, SequenceAlloc, Service};

rosidl_runtime_rs/src/traits.rs

@@ -160,3 +160,17 @@ pub trait Service: 'static {
     /// Get a pointer to the correct `rosidl_service_type_support_t` structure.
     fn get_type_support() -> *const std::os::raw::c_void;
 }
+
+/// Trait for actions.
+///
+/// User code never needs to call this trait's method, much less implement this trait.
+pub trait Action: 'static {
+    /// The goal message associated with this service.
+    type Goal: Message;
+
+    /// The result message associated with this service.
+    type Result: Message;
+
+    /// The feedback message associated with this service.
+    type Feedback: Message;
+}