Robot control components

hardware_interface/CMakeLists.txt

@@ -14,6 +14,8 @@ find_package(ament_cmake REQUIRED)
 find_package(control_msgs REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(rcpputils REQUIRED)
+find_package(tinyxml2_vendor REQUIRED)
+find_package(TinyXML2 REQUIRED)
 
 add_library(
   hardware_interface
@@ -41,6 +43,21 @@ ament_target_dependencies(
 # which is appropriate when building the dll but not consuming it.
 target_compile_definitions(hardware_interface PRIVATE "HARDWARE_INTERFACE_BUILDING_DLL")
 
+add_library(
+  component_parser
+  src/component_parser.cpp
+)
+target_include_directories(
+  component_parser
+  PUBLIC
+  include
+)
+ament_target_dependencies(
+  component_parser
+  TinyXML2
+)
+target_compile_definitions(component_parser PRIVATE "HARDWARE_INTERFACE_BUILDING_DLL")
+
 add_library(
   components
   SHARED
@@ -52,8 +69,6 @@ target_include_directories(
   PUBLIC
   include
 )
-# Causes the visibility macros to use dllexport rather than dllimport,
-# which is appropriate when building the dll but not consuming it.
 target_compile_definitions(components PRIVATE "HARDWARE_INTERFACE_BUILDING_DLL")
 
 install(
@@ -63,6 +78,7 @@ install(
 
 install(
   TARGETS
+  component_parser
   components
   hardware_interface
   RUNTIME DESTINATION bin
@@ -93,6 +109,11 @@ if(BUILD_TESTING)
   target_link_libraries(test_actuator_handle hardware_interface)
   ament_target_dependencies(test_actuator_handle rcpputils)
 
+  ament_add_gmock(test_component_parser test/test_component_parser.cpp)
+  target_include_directories(test_component_parser PRIVATE include)
+  target_link_libraries(test_component_parser component_parser)
+  ament_target_dependencies(test_component_parser TinyXML2)
+
   ament_add_gmock(test_component_interfaces test/test_component_interfaces.cpp)
   target_include_directories(test_component_interfaces PRIVATE include)
   target_link_libraries(test_component_interfaces components hardware_interface)
@@ -102,6 +123,7 @@ ament_export_include_directories(
   include
 )
 ament_export_libraries(
+  component_parser
   components
   hardware_interface
 )

hardware_interface/include/hardware_interface/component_parser.hpp

@@ -0,0 +1,127 @@
+// Copyright 2020 ros2_control Development Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef HARDWARE_INTERFACE__COMPONENT_PARSER_HPP_
+#define HARDWARE_INTERFACE__COMPONENT_PARSER_HPP_
+
+#include <tinyxml2.h>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "hardware_interface/components/component_info.hpp"
+#include "hardware_interface/hardware_info.hpp"
+#include "hardware_interface/visibility_control.h"
+
+namespace hardware_interface
+{
+
+/**
+  * \brief Search XML snippet from URDF for information about a control component.
+  *
+  * \param urdf string with robot's URDF
+  * \return vector filled with information about robot's control resources
+  * \throws std::runtime_error if a robot attribute or tag is not found
+  */
+HARDWARE_INTERFACE_PUBLIC
+std::vector<HardwareInfo> parse_control_resources_from_urdf(const std::string & urdf);
+
+/**
+ * \brief Parse a control resource from an "ros2_control" tag.
+ *
+ * \param ros2_control_it pointer to ros2_control element with informtions about resource.
+ * \return robot_control_components::ComponentInfo filled with information about the robot
+ * \throws std::runtime_error if a attributes or tag are not found
+ */
+HARDWARE_INTERFACE_PUBLIC
+HardwareInfo parse_resource_from_xml(const tinyxml2::XMLElement * ros2_control_it);
+
+/**
+ * \brief Gets value of the attribute on an XMLelement.
+ * If attribute is not found throws an error.
+ *
+ * \param element_it XMLElement iterator to search for the attribute
+ * \param attribute_name atribute name to serach for and return value
+ * \param tag_name parent tag name where attribute is searched for (used for error output)
+ * \return attribute value
+ * \throws std::runtime_error if attribute is not found
+ */
+HARDWARE_INTERFACE_PUBLIC
+std::string get_attribute_value(
+  const tinyxml2::XMLElement * element_it,
+  const char * attribute_name, const char * tag_name);
+
+/**
+ * \brief Gets value of the text between tags.
+ *
+ * \param element_it XMLElement iterator to search for the text.
+ * \param tag_name parent tag name where text is searched for (used for error output)
+ * \return text of for the tag
+ * \throws std::runtime_error if text is not found
+ */
+HARDWARE_INTERFACE_PUBLIC
+std::string get_text_for_element(
+  const tinyxml2::XMLElement * element_it,
+  const std::string & tag_name);
+
+/**
+ * \brief Gets value of the attribute on an XMLelement.
+ * If attribute is not found throws an error.
+ *
+ * \param element_it XMLElement iterator to search for the attribute
+ * \param attribute_name atribute name to serach for and return value
+ * \param tag_name parent tag name where attribute is searched for (used for error output)
+ * \return attribute value
+ * \throws std::runtime_error if attribute is not found
+ */
+HARDWARE_INTERFACE_PUBLIC
+std::string get_attribute_value(
+  const tinyxml2::XMLElement * element_it,
+  const char * attribute_name, std::string tag_name);
+
+/**
+  * \brief Search XML snippet from URDF for information about a control component.
+  *
+  * \param component_it pointer to the iterator where component info should be found
+  * \return robot_control_components::ComponentInfo filled with information about component
+  * \throws std::runtime_error if a component attribute or tag is not found
+  */
+HARDWARE_INTERFACE_PUBLIC
+components::ComponentInfo parse_component_from_xml(const tinyxml2::XMLElement * component_it);
+
+/**
+ * \brief Search XML snippet for definition of interfaceTypes.
+ *
+ * \param interfaces_it pointer to the interator over interfaces
+ * \param interfaceTag interface type tag (command or state)
+ * \return std::vector< std::__cxx11::string > list of interface types
+ * \throws std::runtime_error if the interfaceType text not set in a tag
+ */
+HARDWARE_INTERFACE_PUBLIC
+std::vector<std::string> parse_interfaces_from_xml(
+  const tinyxml2::XMLElement * interfaces_it, const char * interfaceTag);
+
+/**
+ * \brief Search XML snippet from URDF for parameters.
+ *
+ * \param params_it pointer to the iterator where parameters info should be found
+ * \return std::map< std::__cxx11::string, std::__cxx11::string > key-value map with parameters
+ * \throws std::runtime_error if a component attribute or tag is not found
+ */
+HARDWARE_INTERFACE_PUBLIC
+std::unordered_map<std::string, std::string> parse_parameters_from_xml(
+  const tinyxml2::XMLElement * params_it);
+
+}  // namespace hardware_interface
+#endif  // HARDWARE_INTERFACE__COMPONENT_PARSER_HPP_