Add RunOnce, based on #472

include/behaviortree_cpp/behavior_tree.h

@@ -29,6 +29,7 @@
 #include "behaviortree_cpp/decorators/inverter_node.h"
 #include "behaviortree_cpp/decorators/retry_node.h"
 #include "behaviortree_cpp/decorators/repeat_node.h"
+#include "behaviortree_cpp/decorators/run_once_node.h"
 #include "behaviortree_cpp/decorators/subtree_node.h"
 
 #include "behaviortree_cpp/actions/always_success_node.h"

include/behaviortree_cpp/decorators/run_once_node.h

@@ -0,0 +1,82 @@
+/*  Copyright (C) 2023 Davide Faconti -  All Rights Reserved
+*   Copyright (C) 2022 Gaël Écorchard, Czech Institute of Informatics, Robotics, and Cybernetics (ciirc) <[email protected]>
+*
+*   Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
+*   to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+*   and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+*   The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+*
+*   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+*   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+*   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#pragma once
+
+#include "behaviortree_cpp/decorator_node.h"
+
+
+namespace BT {
+
+/**
+ * @brief The RunOnceNode is used when you want to execute the child
+ * only once.
+ * If the child is asynchronous, we will tick until either SUCCESS or FAILURE is
+ * returned.
+ *
+ * After that first execution, you can set value of the port "then_skip" to:
+ *
+ * - if TRUE (default), the node will be skipped in the future.
+ * - if FALSE, return synchronously the same status returned by the child, forever.
+ */
+class RunOnceNode : public DecoratorNode
+{
+  public:
+  RunOnceNode(const std::string& name, const NodeConfig& config) :
+            DecoratorNode(name, config)
+  {
+    setRegistrationID("RunOnce");
+  }
+
+  static PortsList providedPorts()
+  {
+    return {InputPort<bool>(
+        "then_skip", true,
+        "If true, skip after the first execution, "
+        "otherwise return the same NodeStatus returned once bu the child.")};
+  }
+
+  private:
+
+  virtual BT::NodeStatus tick() override;
+
+  bool already_ticked_ = false;
+  NodeStatus returned_status_ = NodeStatus::IDLE;
+};
+
+//------------ implementation ----------------------------
+
+inline NodeStatus RunOnceNode::tick()
+{
+  bool skip = true;
+  if(auto const res = getInput<bool>("then_skip"))
+  {
+    skip = res.value();
+  }
+
+  if (already_ticked_)
+  {
+    return skip ? NodeStatus::SKIPPED : returned_status_;
+  }
+
+  setStatus(NodeStatus::RUNNING);
+  auto const status = child_node_->executeTick();
+
+  if(isStatusCompleted(status) ) {
+    already_ticked_ = true;
+    returned_status_ = status;
+  }
+  return status;
+}
+
+}   // namespace BT

src/bt_factory.cpp

@@ -48,6 +48,7 @@ BehaviorTreeFactory::BehaviorTreeFactory()
   registerNodeType<RepeatNode>("Repeat");
   registerNodeType<TimeoutNode<>>("Timeout");
   registerNodeType<DelayNode>("Delay");
+  registerNodeType<RunOnceNode>("RunOnce");
 
   registerNodeType<ForceSuccessNode>("ForceSuccess");
   registerNodeType<ForceFailureNode>("ForceFailure");

tests/gtest_decorator.cpp

@@ -12,8 +12,8 @@
 
 #include <gtest/gtest.h>
 #include "action_test_node.h"
-#include "condition_test_node.h"
-#include "behaviortree_cpp/behavior_tree.h"
+#include "behaviortree_cpp/bt_factory.h"
+#include "test_helper.hpp"
 
 using BT::NodeStatus;
 using std::chrono::milliseconds;
@@ -27,7 +27,7 @@ struct DeadlineTest : testing::Test
   {
     root.setChild(&action);
   }
-  ~DeadlineTest() = default;
+  ~DeadlineTest() override = default;
 };
 
 struct RepeatTest : testing::Test
@@ -39,7 +39,7 @@ struct RepeatTest : testing::Test
   {
     root.setChild(&action);
   }
-  ~RepeatTest() = default;
+  ~RepeatTest() override = default;
 };
 
 struct RepeatTestAsync : testing::Test
@@ -51,7 +51,7 @@ struct RepeatTestAsync : testing::Test
   {
     root.setChild(&action);
   }
-  ~RepeatTestAsync() = default;
+  ~RepeatTestAsync() override = default;
 };
 
 struct RetryTest : testing::Test
@@ -63,7 +63,7 @@ struct RetryTest : testing::Test
   {
     root.setChild(&action);
   }
-  ~RetryTest() = default;
+  ~RetryTest() override = default;
 };
 
 struct TimeoutAndRetry : testing::Test
@@ -189,3 +189,34 @@ TEST_F(TimeoutAndRetry, Issue57)
     std::this_thread::sleep_for(std::chrono::microseconds(50));
   }
 }
+
+TEST(Decorator, RunOnce)
+{
+  BT::BehaviorTreeFactory factory;
+  std::array<int, 2> counters;
+  RegisterTestTick(factory, "Test", counters);
+
+  const std::string xml_text = R"(
+    <root BTCPP_format="4" >
+       <BehaviorTree>
+          <Sequence>
+            <RunOnce> <TestA/> </RunOnce>
+            <TestB/>
+          </Sequence>
+       </BehaviorTree>
+    </root>)";
+
+  auto tree = factory.createTreeFromText(xml_text);
+
+  for(int i=0; i<5; i++)
+  {
+    NodeStatus status = tree.tickWhileRunning();
+    ASSERT_EQ(status, NodeStatus::SUCCESS);
+  }
+  // counters[0] contains the number ot times TestA was ticked
+  ASSERT_EQ(counters[0], 1);
+  // counters[1] contains the number ot times TestB was ticked
+  ASSERT_EQ(counters[1], 5);
+}
+
+

tests/gtest_skipping.cpp

@@ -175,3 +175,50 @@ TEST(SkippingLogic, SkippingReactiveSequence)
   // counters[1] contains the number ot times TestB was ticked
   ASSERT_EQ(counters[1], 0);
 }
+
+
+
+TEST(SkippingLogic, WhileSkip)
+{
+  BehaviorTreeFactory factory;
+  std::array<int, 2> counters;
+  RegisterTestTick(factory, "Test", counters);
+
+  const std::string xml_text_noskip = R"(
+    <root BTCPP_format="4" >
+       <BehaviorTree>
+          <Sequence>
+            <Script code=" doit:=true "/>
+            <Sequence>
+              <TestA _while="doit"/>
+            </Sequence>
+          </Sequence>
+       </BehaviorTree>
+    </root>)";
+
+  const std::string xml_text_skip = R"(
+    <root BTCPP_format="4" >
+       <BehaviorTree>
+          <Sequence>
+            <Script code=" doit:=false "/>
+            <Sequence>
+              <TestB _while="doit"/>
+            </Sequence>
+          </Sequence>
+       </BehaviorTree>
+    </root>)";
+
+
+  for(auto const* xml_text: {&xml_text_noskip, &xml_text_skip})
+  {
+    auto tree = factory.createTreeFromText(*xml_text);
+    NodeStatus status = tree.tickWhileRunning();
+    ASSERT_EQ(status, NodeStatus::SUCCESS);
+  }
+  // counters[0] contains the number ot times TestA was ticked
+  ASSERT_EQ(counters[0], 1);
+
+  // counters[1] contains the number ot times TestB was ticked
+  ASSERT_EQ(counters[1], 0);
+}
+