fix issue #530: use convertFromString in scripting assignments

Author: facontidavide

include/behaviortree_cpp/scripting/operators.hpp

@@ -361,7 +361,7 @@ struct ExprAssignment : ExprBase
         const auto& key = varname->name;
 
         std::unique_lock entry_lock(env.vars->entryMutex());
-        auto any_ptr = env.vars->getAny(key);
+        Any* any_ptr = env.vars->getAny(key);
         if( !any_ptr )
         {
             // variable doesn't exist, create it if using operator assign_create
@@ -379,7 +379,33 @@ struct ExprAssignment : ExprBase
 
         if( op == assign_create || op == assign_existing )
         {
-            value.copyInto(*any_ptr);
+            // special case first: string to other type
+            // check if we can use the StringConverter
+            if(value.isString() && !any_ptr->isString())
+            {
+                auto const str = value.cast<std::string>();
+                if(auto converter = env.vars->portInfo(key)->converter())
+                {
+                    *any_ptr = converter(str);
+                }
+                else {
+                    auto msg = StrCat("Type mismatch in scripting:",
+                                      " can't convert the string '", str,
+                                      "' to the type expected by that port.\n"
+                                      "Have you implemented the relevant "
+                                      "convertFromString<T>() ?");
+                    throw RuntimeError(msg);
+                }
+            }
+            else {
+                try {
+                    value.copyInto(*any_ptr);
+                }
+                catch (std::runtime_error) {
+                    throw RuntimeError("A script failed to convert the given type "
+                                       "to the one expected by that port.");
+                }
+            }
             return *any_ptr;
         }
 

tests/gtest_subtree.cpp

@@ -1,6 +1,7 @@
 #include <gtest/gtest.h>
 #include "behaviortree_cpp/bt_factory.h"
 #include "../sample_nodes/dummy_nodes.h"
+#include "../sample_nodes/movebase_node.h"
 
 using namespace BT;
 
@@ -283,3 +284,45 @@ TEST(SubTree, ScriptRemap)
   ASSERT_EQ(tree.subtrees[1]->blackboard->get<int>("value"), 1);
   ASSERT_EQ(tree.subtrees[0]->blackboard->get<int>("value"), 1);
 }
+
+class ModifyPose : public BT::SyncActionNode
+{
+public:
+  // Any TreeNode with ports must have a constructor with this signature
+  ModifyPose(const std::string& name, const BT::NodeConfig& config)
+    : SyncActionNode(name, config)
+  {}
+
+  static BT::PortsList providedPorts() {
+    return{ BT::BidirectionalPort<Pose2D>("pose") };
+  }
+
+  BT::NodeStatus tick() override {
+    Pose2D pose;
+    getInput("pose", pose);
+    pose.theta *= 2;
+    setOutput("pose", pose);
+    return NodeStatus::SUCCESS;
+  }
+};
+
+TEST(SubTree, StringConversions_Issue530)
+{
+  const char* xml_text = R"(
+<root BTCPP_format="4" >
+  <BehaviorTree ID="MainTree">
+    <Sequence>
+      <Script code=" pose:='1;2;3' "/>
+      <ModifyPose pose="{pose}"/>
+      <Script code=" pose:='1;2;3' "/>
+    </Sequence>
+  </BehaviorTree>
+</root>
+)";
+
+  BT::BehaviorTreeFactory factory;
+  factory.registerNodeType<ModifyPose>("ModifyPose");
+  factory.registerBehaviorTreeFromText(xml_text);
+  Tree tree = factory.createTree("MainTree");
+  tree.tickOnce();
+}