From ac4056e96d267976d48b3bae2b1a6e23e7367a2a Mon Sep 17 00:00:00 2001
From: Andrew Johnson <drewej@protonmail.com>
Date: Tue, 11 Jun 2019 12:23:38 -0400
Subject: [PATCH] Support depletion_chain in DataLibrary to/from xml and
 register

DataLibrary.from_xml looks for depletion_chain node in the
cross sections xml file. If found the path to this file is added
to the list of libraries. An empty list of materials is used
for consistency with other libraries. Type and path attributes
are consistent.

DataLibrary.export_to_xml does not write the materials
attribute if the value stored in that library evaluates to False,
e.g. for the empty list stored in the depletion chain.

DataLibrary.register_file has a conditional wherein a passed xml
file is treated as the depletion_chain and hdf5 files are
treated as material/isotopic cross section files.
---
 openmc/data/library.py | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/openmc/data/library.py b/openmc/data/library.py
index e090b2062f..d1a0d778d9 100644
--- a/openmc/data/library.py
+++ b/openmc/data/library.py
@@ -51,6 +51,8 @@ class DataLibrary(EqualityMixin):
         ----------
         filename : str or Path
             Path to the file to be registered.
+            If an ``xml`` file, treat as the depletion chain file without
+            materials.
 
         """
         if not isinstance(filename, pathlib.Path):
@@ -58,9 +60,17 @@ class DataLibrary(EqualityMixin):
         else:
             path = filename
 
-        with h5py.File(path, 'r') as h5file:
-            filetype = h5file.attrs['filetype'].decode()[5:]
-            materials = list(h5file)
+        if path.suffix == '.xml':
+            filetype = 'depletion_chain'
+            materials = []
+        elif path.suffix == '.h5':
+            with h5py.File(path, 'r') as h5file:
+                filetype = h5file.attrs['filetype'].decode()[5:]
+                materials = list(h5file)
+        else:
+            raise ValueError(
+                "File type {} not supported by {}"
+                .format(path.name, self.__class__.__name__))
 
         library = {'path': path.name, 'type': filetype, 'materials': materials}
         self.libraries.append(library)
@@ -88,7 +98,8 @@ class DataLibrary(EqualityMixin):
 
         for library in self.libraries:
             lib_element = ET.SubElement(root, "library")
-            lib_element.set('materials', ' '.join(library['materials']))
+            if library['materials']:
+                lib_element.set('materials', ' '.join(library['materials']))
             lib_element.set('path', os.path.relpath(library['path'], common_dir))
             lib_element.set('type', library['type'])
 
@@ -108,7 +119,7 @@ class DataLibrary(EqualityMixin):
         ----------
         path : str, optional
             Path to XML file to read. If not provided, the
-            `OPENMC_CROSS_SECTIONS` environment variable will be  used.
+            :envvar:`OPENMC_CROSS_SECTIONS` environment variable will be  used.
 
         Returns
         -------
@@ -148,4 +159,13 @@ class DataLibrary(EqualityMixin):
                        'materials': materials}
             data.libraries.append(library)
 
+        # get depletion chain data
+
+        dep_node = root.find("depletion_chain")
+        if dep_node is not None:
+            filename = os.path.join(directory, dep_node.attrib['path'])
+            library = {'path': filename, 'type': 'depletion_chain',
+                       'materials': []}
+            data.libraries.append(library)
+
         return data