ENH: Add examples to the template.

Add a hint to foster writing examples for the contributed classes.

cookiecutter.json

@@ -5,6 +5,7 @@
   "module_name": "{{ cookiecutter.project_name[3:] }}",
   "filter_name": "MyFilter",
   "python_package_name": "itk-{{ cookiecutter.project_name[3:].lower() }}",
+  "example_name": "MyFilterApplicationWholePipeline",
   "download_url": "https://github.com/InsightSoftwareConsortium/{{ cookiecutter.project_name }}",
   "project_short_description": "This is a template that serves as a starting point for a new module.",
   "project_long_description": "ITK is an open-source, cross-platform library that provides developers with an extensive suite of software tools for image analysis. Developed through extreme programming methodologies, ITK employs leading-edge algorithms for registering and segmenting multidimensional scientific images."

{{cookiecutter.project_name}}/CMakeLists.txt

@@ -11,3 +11,5 @@ else()
   set(ITK_DIR ${CMAKE_BINARY_DIR})
   itk_module_impl()
 endif()
+
+itk_module_examples()

{{cookiecutter.project_name}}/examples/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.16.3)
+project({{ cookiecutter.module_name }}Examples)
+
+set(ExampleSpecificComponents
+  {{ cookiecutter.module_name }}
+  )
+
+if(NOT ITK_SOURCE_DIR)
+  find_package(ITK REQUIRED COMPONENTS ITKImageIO ITKTransformIO ${ExampleSpecificComponents})
+else()
+  # When being built as part of ITK, ITKImageIO and ITKTransformIO
+  # lists of modules are not yet ready, causing a configure error
+  find_package(ITK REQUIRED COMPONENTS ${ExampleSpecificComponents})
+endif()
+include(${ITK_USE_FILE})
+
+add_executable({{ cookiecutter.example_name }} {{ cookiecutter.example_name }}.cxx )
+target_link_libraries({{ cookiecutter.example_name }} ${ITK_LIBRARIES})

{{cookiecutter.project_name}}/examples/{{ cookiecutter.example_name }}.cxx

@@ -0,0 +1,45 @@
+/*=========================================================================
+ *
+ *  Copyright NumFOCUS
+ *
+ *  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
+ *
+ *         https://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ *  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.
+ *
+ *=========================================================================*/
+
+#include "itk{{cookiecutter.filter_name}}.h"
+
+#include "itkCommand.h"
+#include "itkImageFileReader.h"
+#include "itkImageFileWriter.h"
+
+
+int main( int argc, char * argv[] )
+{
+  if( argc < 4 )
+    {
+    std::cerr << "Missing parameters." << std::endl;
+    std::cerr << "Usage: " << argv[0]
+      << " inputImage"
+      << " outputImage"
+      << " parameters" << std::endl;
+    return EXIT_FAILURE;
+    }
+
+
+  // Please, write a complete, self-containted and useful example that
+  // demonstrate a class when being used along with other ITK classes or in
+  // the context of a wider or specific application.
+
+
+  return EXIT_SUCCESS;
+}

{{cookiecutter.project_name}}/examples/{{ cookiecutter.example_name }}.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+
+# Copyright NumFOCUS
+#
+#  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
+#
+#         https://www.apache.org/licenses/LICENSE-2.0.txt
+#
+#  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.
+
+# Run with:
+# ./{{ cookiecutter.example_name }}.py <input_image> <output_image>
+# <parameters>
+# e.g.
+# ./{{ cookiecutter.example_name }}.py MyImage.mha Output.mha 2 0.2
+# (A rule of thumb is to set the Threshold to be about 1 / 100 of the Level.)
+#
+#  parameter_1: absolute minimum...
+#        The assumption is that...
+#  parameter_2: controls the..
+#        A tradeoff between...
+
+import argparse
+
+import itk
+
+
+parser = argparse.ArgumentParser(description="Example short description.")
+parser.add_argument("input_image")
+parser.add_argument("output_image")
+parser.add_argument("parameter_1")
+args = parser.parse_args()
+
+# Please, write a complete, self-containted and useful example that
+# demonstrate a class when being used along with other ITK classes or in
+# the context of a wider or specific application.