Feature load from another package

README.md

@@ -34,6 +34,7 @@ See the Tutorials on
 - [How to write your first .params file](doc/HowToWriteYourFirstParamsFile.md)
 - [How to use your parameter struct](doc/HowToUseYourParameterStruct.md)
 - [rosparam_handler_tutorial](https://github.com/cbandera/rosparam_handler_tutorial)
+- [How to import from another .params file](doc/HowToImportFromAnotherParamsFile.md)
 
 ## Installation
 `rosparam_handler` has been released in version `0.1.1` for 

doc/HowToImportFromAnotherParamsFile.md

@@ -0,0 +1,29 @@
+# How to Import from another .params file
+**Description**: This tutorial will show you how to import a .params file from another ROS package instead of copy-pasting it all over.
+**Tutorial Level**: ADVANCED
+
+## Setup
+
+Note that your package will still need to depend on rosparam_handler and dynamic_reconfigure.
+
+You can find an example of a minimal package called [imported_rosparam_handler_test](https://github.com/awesomebytes/imported_rosparam_handler_test) which imports from [rosparam_handler_tutorial](https://github.com/cbandera/rosparam_handler_tutorial).
+
+
+## The params File
+
+```python
+#!/usr/bin/env python
+from rosparam_handler.parameter_generator_catkin import *
+gen = ParameterGenerator()
+# Do it at the start, as it overwrites all current params
+gen.initialize_from_file('rosparam_handler_tutorial', 'Demo.params')
+
+# Do your usual business
+gen.add("some_other_param", paramtype="int",description="Awesome int", default=2, min=1, max=10, configurable=True)
+gen.add("non_configurable_thing", paramtype="int",description="Im not configurable", default=2, min=1, max=10, configurable=False)
+
+# Syntax : Package, Node, Config Name(The final name will be MyDummyConfig)
+exit(gen.generate("imported_rosparam_handler_test", "example_node", "Example"))
+```
+
+You just need to call `initialize_from_file(ros_package_name, File.params)`. Note that it will overwrite all params. Should be called at the start (that's why it's called initialize).

doc/HowToWriteYourFirstParamsFile.md

@@ -150,7 +150,7 @@ NOTE: The third parameter should be equal to the params file name, without exten
 
 ## Add params file to CMakeLists
 
-In order to make this params file usable it must be executable, so lets use the following command to make it excecutable
+In order to make this params file usable it must be executable, so lets use the following command to make it executable
 
 ```shell
 chmod a+x cfg/Tutorials.params

src/rosparam_handler/parameter_generator_catkin.py

@@ -31,6 +31,7 @@
 import sys
 import os
 import re
+from parameter_importer import load_generator
 
 
 def eprint(*args, **kwargs):
@@ -56,19 +57,46 @@ def __init__(self, parent=None, group=""):
             self.group = "gen"
         self.group_variable = filter(str.isalnum, self.group)
 
-        if len(sys.argv) != 5:
-            eprint(
-                "ParameterGenerator: Unexpected amount of args, did you try to call this directly? You shouldn't do this!")
-
-        self.dynconfpath = sys.argv[1]
-        self.share_dir = sys.argv[2]
-        self.cpp_gen_dir = sys.argv[3]
-        self.py_gen_dir = sys.argv[4]
-
         self.pkgname = None
         self.nodename = None
         self.classname = None
 
+    def _load_generator(self, package_name, params_file_name):
+        """
+        Load from another package .params file it's generator.
+        :param package_name: name of the package where the .params file is
+        :param params_file_name: name of the .params file, in the cfg folder
+        :return: ParameterGenerator instance from the provided file
+        """
+        gen = load_generator(package_name, params_file_name)
+        if gen is None:
+            eprint("Could not load generator from package " + package_name +
+                   " and file " + params_file_name)
+        return gen
+
+    def _initialize_from_generator(self, generator):
+        """
+        Initialize this ParameterGenerator from another instance.
+        :param generator: a ParameterGenerator instance
+        :return:
+        """
+        self.enums = generator.enums
+        self.parameters = generator.parameters
+        self.childs = generator.childs
+        self.parent = generator.parent
+        self.group = generator.group
+        self.group_variable = generator.group_variable
+
+    def initialize_from_file(self, package_name, params_file_name):
+        """
+        Initialize this ParameterGenerator from another package .params file.
+        :param package_name: name of the package where the .params file is
+        :param params_file_name: name of the .params file, in the cfg folder
+        :return:
+        """
+        self._initialize_from_generator(self._load_generator(package_name,
+                                                             params_file_name))
+
     def add_group(self, name):
         """
         Add a new group in the dynamic reconfigure selection
@@ -327,6 +355,15 @@ def generate(self, pkgname, nodename, classname):
         self.nodename = nodename
         self.classname = classname
 
+        if len(sys.argv) != 5:
+            eprint(
+                "ParameterGenerator: Unexpected amount of args, did you try to call this directly? You shouldn't do this!")
+
+        self.dynconfpath = sys.argv[1]
+        self.share_dir = sys.argv[2]
+        self.cpp_gen_dir = sys.argv[3]
+        self.py_gen_dir = sys.argv[4]
+
         if self.parent:
             eprint("You should not call generate on a group! Call it on the main parameter generator instead!")
 

src/rosparam_handler/parameter_importer.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2017, Sammy Pfeiffer
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+#     * Neither the name of the organization nor the
+#       names of its contributors may be used to endorse or promote products
+#       derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Author: Sammy Pfeiffer
+#
+# Utilities to import from another package .params file
+#
+
+from imp import load_source
+from rospkg import RosPack, ResourceNotFound
+from tempfile import NamedTemporaryFile
+import cStringIO
+import tokenize
+import re
+
+
+def remove_comments(source):
+    """
+    Returns 'source' minus comments, based on
+    https://stackoverflow.com/a/2962727
+    """
+    io_obj = cStringIO.StringIO(source)
+    out = ""
+    last_lineno = -1
+    last_col = 0
+    for tok in tokenize.generate_tokens(io_obj.readline):
+        token_type = tok[0]
+        token_string = tok[1]
+        start_line, start_col = tok[2]
+        end_line, end_col = tok[3]
+        if start_line > last_lineno:
+            last_col = 0
+        if start_col > last_col:
+            out += (" " * (start_col - last_col))
+        # Remove comments:
+        if token_type == tokenize.COMMENT:
+            pass
+        else:
+            out += token_string
+        last_col = end_col
+        last_lineno = end_line
+    return out
+
+
+def load_generator(package_name, params_file_name):
+    """
+    Returns the generator created in another .params file from another package.
+    Python does not allow to import from files without the extension .py
+    so we need to hack a bit to be able to import from .params file.
+    Also the .params file was never thought to be imported, so we need
+    to do some extra tricks.
+    """
+    # Get the file path
+    rp = RosPack()
+    try:
+        pkg_path = rp.get_path(package_name)
+    except ResourceNotFound:
+        return None
+    full_file_path = pkg_path + '/cfg/' + params_file_name
+    # print("Loading rosparam_handler params from file: " + full_file_path)
+
+    # Read the file and check for exit() calls
+    # Look for line with exit function to not use it or we will get an error
+    with open(full_file_path, 'r') as f:
+        file_str = f.read()
+    # Remove all comment lines first
+    clean_file = remove_comments(file_str)
+    # Find exit( calls
+    exit_finds = [m.start() for m in re.finditer('exit\(', clean_file)]
+    # If there are, get the last one
+    if exit_finds:
+        last_exit_idx = exit_finds[-1]
+        clean_file = clean_file[:last_exit_idx]
+        with NamedTemporaryFile() as f:
+            f.file.write(clean_file)
+            f.file.close()
+            tmp_module = load_source('tmp_module', f.name)
+    else:
+        # Looks like the exit call is not there
+        # or it's surrounded by if __name__ == '__main__'
+        # so we can just load the source
+        tmp_module = load_source('tmp_module', full_file_path)
+
+    for var in dir(tmp_module):
+        if not var.startswith('_'):
+            module_element = getattr(tmp_module, var)
+            type_str = str(type(module_element))
+            # Looks like:
+            # <class 'PACKAGE_NAME.parameter_generator_catkin.ParameterGenerator'>
+            if 'parameter_generator_catkin.ParameterGenerator' in type_str:
+                return module_element
+
+    return None