fixing issue microsoft#22

getParam refering to a blackboard would always fail in the constructor,
because the blackboard pointer is still null.

include/behaviortree_cpp/decorators/timeout_node.h

@@ -33,6 +33,7 @@ class TimeoutNode : public DecoratorNode
     uint64_t timer_id_;
 
     unsigned msec_;
+    bool refresh_parameter_;
 };
 }
 

src/controls/parallel_node.cpp

@@ -28,14 +28,17 @@ ParallelNode::ParallelNode(const std::string& name, int threshold)
 ParallelNode::ParallelNode(const std::string &name,
                                const NodeParameters &params)
     : ControlNode::ControlNode(name, params),
-    refresh_parameter_(false)
-  {
-    if( !getParam(THRESHOLD_KEY, threshold_) )
+      refresh_parameter_(false)
+{
+    refresh_parameter_ = isBlackboardPattern( params.at(THRESHOLD_KEY) );
+    if(!refresh_parameter_)
     {
-        throw std::runtime_error("Missing parameter [threshold] in ParallelNode");
+        if( !getParam(THRESHOLD_KEY, threshold_) )
+        {
+            throw std::runtime_error("Missing parameter [threshold] in ParallelNode");
+        }
     }
-    refresh_parameter_ = isBlackboardPattern( params.at(THRESHOLD_KEY) );
-  }
+}
 
 NodeStatus ParallelNode::tick()
 {

src/controls/sequence_star_node.cpp

@@ -30,11 +30,14 @@ SequenceStarNode::SequenceStarNode(const std::string& name, const NodeParameters
   : ControlNode::ControlNode(name, params), current_child_idx_(0),
     refresh_parameter_(false)
 {
-    if( !getParam(RESET_PARAM, reset_on_failure_) )
+    refresh_parameter_ = isBlackboardPattern( params.at(RESET_PARAM) );
+    if(!refresh_parameter_)
     {
-        throw std::runtime_error("Missing parameter [reset_on_failure] in SequenceStarNode");
+        if( !getParam(RESET_PARAM, reset_on_failure_) )
+        {
+            throw std::runtime_error("Missing parameter [reset_on_failure] in SequenceStarNode");
+        }
     }
-    refresh_parameter_ = isBlackboardPattern( params.at(RESET_PARAM) );
 }
 
 NodeStatus SequenceStarNode::tick()

src/decorators/repeat_node.cpp

@@ -30,11 +30,14 @@ RepeatNode::RepeatNode(const std::string& name, const NodeParameters& params)
     try_index_(0),
     refresh_parameter_(false)
 {
-    if( !getParam(NUM_CYCLES, num_cycles_) )
+    refresh_parameter_ = isBlackboardPattern( params.at(NUM_CYCLES) );
+    if(!refresh_parameter_)
     {
-        throw std::runtime_error("Missing parameter [num_cycles] in RepeatNode");
+        if( !getParam(NUM_CYCLES, num_cycles_) )
+        {
+            throw std::runtime_error("Missing parameter [num_cycles] in RepeatNode");
+        }
     }
-    refresh_parameter_ = isBlackboardPattern( params.at(NUM_CYCLES) );
 }
 
 NodeStatus RepeatNode::tick()

src/decorators/retry_node.cpp

@@ -30,11 +30,14 @@ RetryNode::RetryNode(const std::string& name, const NodeParameters& params)
     try_index_(0),
     refresh_parameter_(false)
 {
-    if( !getParam(NUM_ATTEMPTS, max_attempts_) )
+    refresh_parameter_ = isBlackboardPattern( params.at(NUM_ATTEMPTS) );
+    if(!refresh_parameter_)
     {
-        throw std::runtime_error("Missing parameter [num_attempts] in RetryNode");
+        if( !getParam(NUM_ATTEMPTS, max_attempts_) )
+        {
+            throw std::runtime_error("Missing parameter [num_attempts] in RetryNode");
+        }
     }
-    refresh_parameter_ = isBlackboardPattern( params.at(NUM_ATTEMPTS) );
 }
 
 NodeStatus RetryNode::tick()

src/decorators/timeout_node.cpp

@@ -21,15 +21,23 @@ TimeoutNode::TimeoutNode(const std::string& name, unsigned milliseconds)
 TimeoutNode::TimeoutNode(const std::string& name, const BT::NodeParameters& params)
   : DecoratorNode(name, params), child_halted_(false), msec_(0)
 {
-    auto param = getParam<unsigned>("msec");
-    if (param)
+    refresh_parameter_ = isBlackboardPattern( params.at("msec") );
+    if(!refresh_parameter_)
     {
-        msec_ = param.value();
+        if( !getParam("msec", msec_) )
+        {
+            throw std::runtime_error("Missing parameter [msec] in TimeoutNode");
+        }
     }
 }
 
 NodeStatus TimeoutNode::tick()
 {
+    if( refresh_parameter_ )
+    {
+        getParam("msec", msec_);
+    }
+
     if (status() == NodeStatus::IDLE)
     {
         setStatus(NodeStatus::RUNNING);