Add an abstract base to generated parameters structures.

doc/HowToUseYourParameterPtr.md

@@ -0,0 +1,117 @@
+# How to Use Your `rosparam_handler::ParameterPtr`
+**Description**: This tutorial will familiarize you with how you can use the autogenerated parameter structs in your nodes from a base class smart-pointer. It is thus recommended to read the tutorial [How to use your parameters struct file](HowToUseYourParametersStruct.md) if you haven't yet.  
+**Tutorial Level**: INTERMEDIATE
+
+## Generated files
+When creating params files as described in [How to write your first .params file](HowToWriteYourFirstParamsFile.md), you will end up with the following two files:
+-   *'include/rosparam_tutorials/TutorialParameters.h'*
+-   *'include/rosparam_tutorials/TutorialConfig.h'*
+
+The '<name>Parameters.h' file will hold a struct called `<name>Parameters`.  
+The '<name>Config.h' file will hold the normal dynamic_reconfigure Config struct.
+
+For your code it is enough to include the \*Parameters.h file, e.g.
+
+```cpp
+#include "rosparam_tutorials/TutorialParameters.h"
+```
+
+You can now add an instance of the base parameter pointer to your class:
+
+```cpp
+rosparam_tutorials::ParametersPtr params_ptr_;
+```
+
+## Initializing the pointer
+When initializing your node, the params pointer `params_ptr_` must be instantiated to the appropriate parameter type with a private `NodeHandle`.
+
+```cpp
+MyNodeClass::MyNodeClass()
+  : params_ptr_{boost::make_shared<TutorialParameters>(ros::NodeHandle("~"))}
+{
+  ...
+}
+```
+
+In case your node has several classes, each using a different `ParameterPtr` object, the private `NodeHandle` must have a sub-namespace that is unique to your object in order to avoid parameters name collision.
+
+```cpp
+MyNodeClass::MyClass()
+  : params_ptr_{boost::make_shared<TutorialParameters>(ros::NodeHandle("~/my_class"))}
+{
+  ...
+}
+
+MyNodeClass::MyOtherClass()
+  : params_ptr_{boost::make_shared<TutorialParameters>(ros::NodeHandle("~/my_other_class"))}
+{
+  ...
+}
+```
+
+## Initializing the struct
+
+The call to `fromParamServer()` is done the very same manner as for a normal parameter object.
+It will take care of getting all parameter values from the parameter server, checking their type, and checking that a default value is set, if you haven't provided one on your own. If you have specified a default value, but the parameter is not yet present on the parameter server, it will be set. When min and max values are specified, these bounds will be checked as well.
+
+```cpp
+MyNodeClass::MyNodeClass()
+  : params_ptr_{boost::make_shared<TutorialParameters>(ros::NodeHandle("~"))}
+{
+  params_ptr_->fromParamServer();
+}
+```
+
+If you do not use a class (which you should do though in my opinion), you can create it like so:
+```cpp
+rosparam_tutorials::ParametersPtr params_ptr{boost::make_shared<TutorialParameters>(ros::NodeHandle("~"))}
+params_ptr->fromParamServer();
+```
+Note: If you have set the logger level for your node to debug, you will get information on which values have been retrieved.  
+Note: If you use nodelets, you have to use the `getPrivateNodeHandle()` function instead.
+
+## Retrieving the actual parameter
+
+Since you are using here a `ParametersPtr`, you cannot access directly the parameters held by the structure:
+```cpp
+params_ptr_->my_int = 42; // Will NOT compile
+```
+
+To do so, you have to cast the base pointer to its appropriate derived type:
+```cpp
+boost::shared_ptr<TutorialParameters> params_ptr_cast = rosparam_handler::dynamic_parameters_cast<TutorialParameters>(params_ptr_);
+assert(params_ptr_cast != nullptr);
+
+if (params_ptr_cast != nullptr)
+{
+  params_ptr_cast->my_int = 42;
+}
+```
+Both dynamic and static cast helper function are provided:
+```cpp
+auto my_cast = rosparam_handler::dynamic_parameters_cast<DerivedType>(ptr);
+auto my_cast = rosparam_handler::static_parameters_cast<DerivedType>(ptr);
+```
+which simply are aliases to:
+```cpp
+auto my_cast = boost::dynamic_pointer_cast<DerivedType>(ptr);
+auto my_cast = boost::static_pointer_cast_cast<DerivedType>(ptr);
+```
+
+## Using dynamic_reconfigure
+Your dynamic_reconfigure callback can now look as simple as:
+```cpp
+void reconfigureRequest(TutorialConfig& config, uint32_t level) {
+    params_ptr_->fromConfig(config);
+}
+```
+This will update all values that were specified as configurable. At the same time, it assures that all dynamic_reconfigure parameters live in the same namespace as those on the parameter server to avoid problems with redundant parameters.
+
+You can find a running version of this example code in the [rosparam_handler_tutorial](https://github.com/cbandera/rosparam_handler_tutorial)-Repository
+
+## Setting parameters on the server
+If you change your parameters at runtime from within the code, you can upload the current state of the parameters with
+```cpp
+params_ptr_->toParamServer();
+```
+This will set all non-const parameters with their current value on the ros parameter server.

doc/HowToUseYourParameterStruct.md

@@ -54,6 +54,17 @@ This will update all values that were specified as configurable. At the same tim
 
 You can find a running version of this example code in the [rosparam_handler_tutorial](https://github.com/cbandera/rosparam_handler_tutorial)-Repository
 
+## From another parameters structure
+You can also simply copy your current parameters:
+```cpp
+rosparam_tutorials::TutorialParameters params_{ros::NodeHandle("~")}
+params_.fromParamServer();
+
+rosparam_tutorials::TutorialParameters params_copy_(params_);
+// equivalently
+params_copy_ = params_;
+```
+
 ## Setting parameters on the server
 If you change your parameters at runtime from within the code, you can upload the current state of the parameters with
 ```cpp

include/rosparam_handler/ParametersBase.h

@@ -0,0 +1,103 @@
+/**
+ * \file ParametersBase.h
+ *
+ *  Created on: Oct 28, 2017
+ *
+ *  \authors: Claudio Bandera
+ *            Sascha Wirges
+ *            Niels Ole Salscheider
+ *            Jeremie Deray
+ */
+
+#ifndef _ROSPARAM_HANDLER_PARAMETERS_BASE_H_
+#define _ROSPARAM_HANDLER_PARAMETERS_BASE_H_
+
+#include <ros/param.h>
+#include <ros/node_handle.h>
+#include <rosparam_handler/utilities.hpp>
+#include <rosparam_handler/pointer.hpp>
+
+namespace rosparam_handler {
+
+/// \brief ParametersBase An abstract base struct for struct generated by rosparam_handler.
+struct ParametersBase {
+
+  ParametersBase(const ros::NodeHandle& private_node_handle)
+  : globalNamespace{"/"},
+    privateNamespace{private_node_handle.getNamespace() + "/"},
+    nodeName{rosparam_handler::getNodeName(private_node_handle)} {}
+
+  ParametersBase(const ParametersBase& o)
+  : globalNamespace(o.globalNamespace)
+  , privateNamespace(o.privateNamespace)
+  , nodeName(o.nodeName) {}
+
+  virtual ~ParametersBase() = default;
+
+  ParametersBase& operator=(const ParametersBase& o)
+  {
+    globalNamespace = o.globalNamespace;
+    privateNamespace = o.privateNamespace;
+    nodeName = o.nodeName;
+    return *this;
+  }
+
+  /// \brief Get values from parameter server
+  ///
+  /// Will fail if a value can not be found and no default value is given.
+  inline void fromParamServer(){
+    if(!fromParamServerImpl()){
+      missingParamsWarning();
+      rosparam_handler::exit("RosparamHandler: GetParam could net retrieve parameter.");
+    }
+    ROS_DEBUG_STREAM(*this);
+  }
+
+  /// \brief Set parameters on ROS parameter server.
+  virtual void toParamServer() = 0;
+
+  /// \brief Update configurable parameters.
+  ///
+  /// \param config  dynamic reconfigure struct
+  /// \level ?
+  template <typename T>
+  inline void fromConfig(const T& config, const uint32_t level = 0){
+#ifdef DYNAMIC_RECONFIGURE_FOUND
+  fromConfigImpl<T>(config, level);
+#else
+  ROS_FATAL_STREAM("dynamic_reconfigure was not found during compilation. So fromConfig() is not available. Please recompile with dynamic_reconfigure.");
+  rosparam_handler::exit("dynamic_reconfigure was not found during compilation. So fromConfig() is not available. Please recompile with dynamic_reconfigure.");
+#endif
+  }
+
+  /// \brief Stream operator for printing parameter struct
+  inline friend std::ostream& operator<<(std::ostream& os, const ParametersBase& p)
+  {
+    return p.print(os);
+  }
+
+protected:
+
+  /// \brief The actual implementation of 'fromParamServer'
+  /// overriden by the derived class
+  virtual bool fromParamServerImpl() = 0;
+
+  /// \brief The actual implementation os 'fromConfig' specialized
+  /// for the 'DerivedConfig' type.
+  template <typename T>
+  void fromConfigImpl(const T& config, const uint32_t level);
+
+  /// \brief A helper function for ostram operator <<
+  virtual std::ostream& print(std::ostream& os) const = 0;
+
+  /// \brief Issue a warning about missing default parameters.
+  virtual void missingParamsWarning() = 0;
+
+  std::string globalNamespace = {"/"};
+  std::string privateNamespace;
+  std::string nodeName;
+};
+
+} // namespace rosparam_handler
+
+#endif /* _ROSPARAM_HANDLER_PARAMETERS_BASE_H_ */

include/rosparam_handler/pointer.hpp

@@ -0,0 +1,37 @@
+/**
+ * \file pointer.h
+ *
+ *  Created on: Oct 28, 2017
+ *
+ *  \authors: Jeremie Deray
+ */
+
+#ifndef _ROSPARAM_HANDLER_POINTER_H_
+#define _ROSPARAM_HANDLER_POINTER_H_
+
+#include <boost/shared_ptr.hpp>
+
+namespace rosparam_handler {
+
+/// \brief forward declaration
+struct ParametersBase;
+
+/// \brief base pointer declaration
+using ParametersPtr = boost::shared_ptr<ParametersBase>;
+using ParametersConstPtr = boost::shared_ptr<const ParametersBase>;
+
+template <typename T>
+boost::shared_ptr<T> static_parameters_cast(const rosparam_handler::ParametersPtr& ptr)
+{
+  return boost::static_pointer_cast<T>(ptr);
+}
+
+template <typename T>
+boost::shared_ptr<T> dynamic_parameters_cast(const rosparam_handler::ParametersPtr& ptr)
+{
+  return boost::dynamic_pointer_cast<T>(ptr);
+}
+
+} /* namespace rosparam_handler */
+
+#endif /* _ROSPARAM_HANDLER_POINTER_H_ */

src/rosparam_handler/parameter_generator_catkin.py

@@ -383,6 +383,8 @@ def _generatehpp(self):
             template = f.read()
 
         param_entries = []
+        copy_constructor_entries = []
+        assignment_operator_entries = []
         string_representation = []
         from_server = []
         to_server = []
@@ -405,17 +407,21 @@ def _generatehpp(self):
 
             # Test for default value
             if param["default"] is None:
+                value = ""
                 default = ""
                 non_default_params.append(Template('      << "\t" << $namespace << "$name" << " ($type) '
                                                    '\\n"\n').substitute(
                     namespace=namespace, name=name, type=param["type"]))
             else:
                 if param['is_vector']:
-                    default = ', {}'.format(str(param['type']) + "{" + self._get_cvaluelist(param, "default") + "}")
+                    value = ' = {}'.format("{" + self._get_cvaluelist(param, "default") + "}")
+                    default = ', ' + name
                 elif param['is_map']:
-                    default = ', {}'.format(str(param['type']) + "{" + self._get_cvaluedict(param, "default") + "}")
+                    value = ' = {}'.format("{" + self._get_cvaluedict(param, "default") + "}")
+                    default = ', ' + name
                 else:
-                    default = ', {}'.format(str(param['type']) + "{" + self._get_cvalue(param, "default") + "}")
+                    value = ' = {}'.format(self._get_cvalue(param, "default"))
+                    default = ', ' + name
 
             # Test for constant value
             if param['constant']:
@@ -425,16 +431,18 @@ def _generatehpp(self):
                                                                default=self._get_cvalue(param, "default")))
                 from_server.append(Template('    rosparam_handler::testConstParam($paramname);').substitute(paramname=full_name))
             else:
-                param_entries.append(Template('  ${type} ${name}; /*!< ${description} */').substitute(
-                    type=param['type'], name=name, description=param['description']))
+                param_entries.append(Template('  ${type} ${name}${value}; /*!< ${description} */').substitute(
+                    type=param['type'], name=name, value=value, description=param['description']))
+                copy_constructor_entries.append(Template(' , ${name}(o.${name})').substitute(name=name))
+                assignment_operator_entries.append(Template('  ${name} = o.${name};').substitute(name=name))
                 from_server.append(Template('    success &= rosparam_handler::getParam($paramname, $name$default);').substitute(
                     paramname=full_name, name=name, default=default, description=param['description']))
                 to_server.append(
                     Template('  rosparam_handler::setParam(${paramname},${name});').substitute(paramname=full_name, name=name))
 
             # Test for configurable params
             if param['configurable']:
-                from_config.append(Template('    $name = config.$name;').substitute(name=name))
+                from_config.append(Template('    casted_ref.$name = config.$name;').substitute(name=name))
 
             # Test limits
             if param['is_vector']:
@@ -451,10 +459,12 @@ def _generatehpp(self):
                     paramname=full_name, name=name, max=param['max'], type=ttype))
 
             # Add debug output
-            string_representation.append(Template('      << "\t" << p.$namespace << "$name:" << p.$name << '
+            string_representation.append(Template('      << "\t" << $namespace << "$name:" << $name << '
                                                   '"\\n"\n').substitute(namespace=namespace, name=name))
 
         param_entries = "\n".join(param_entries)
+        copy_constructor_entries = "\n".join(copy_constructor_entries)
+        assignment_operator_entries = "\n".join(assignment_operator_entries)
         string_representation = "".join(string_representation)
         non_default_params = "".join(non_default_params)
         from_server = "\n".join(from_server)
@@ -463,7 +473,10 @@ def _generatehpp(self):
         test_limits = "\n".join(test_limits)
 
         content = Template(template).substitute(pkgname=self.pkgname, ClassName=self.classname,
-                                                parameters=param_entries, fromConfig=from_config,
+                                                parameters=param_entries,
+                                                copyConstructor=copy_constructor_entries,
+                                                assignOperator=assignment_operator_entries,
+                                                fromConfig=from_config,
                                                 fromParamServer=from_server,
                                                 string_representation=string_representation,
                                                 non_default_params=non_default_params, nodename=self.nodename,