stringify: Add optional attributes list to be displayed

Currently, propery type attributes are ignored in the str and json
representations.
If we want to include them, it is required to override to_jsondict()
and from_jsondict() methods.

This patch adds the optional attributes list to specify the addtional
attributes included in the str and json representations.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 16 insertions, 4 deletions

diff --git a/ryu/lib/stringify.py b/ryu/lib/stringify.py
index 81eb6178..94ffbbcb 100644
--- a/ryu/lib/stringify.py
+++ b/ryu/lib/stringify.py
@@ -144,6 +144,15 @@ class StringifyMixin(object):
     _class_prefixes = []
     _class_suffixes = []
 
+    # List of attributes ignored in the str and json representations.
+    _base_attributes = []
+
+    # Optional attributes included in the str and json representations.
+    # e.g.) In case of attributes are property, the attributes will be
+    # skipped in the str and json representations.
+    # Then, please specify the attributes into this list.
+    _opt_attributes = []
+
     def stringify_attrs(self):
         """an override point for sub classes"""
         return obj_python_attrs(self)
@@ -368,14 +377,17 @@ def obj_python_attrs(msg_):
             yield(k, getattr(msg_, k))
         return
     base = getattr(msg_, '_base_attributes', [])
+    opt = getattr(msg_, '_opt_attributes', [])
     for k, v in inspect.getmembers(msg_):
-        if k.startswith('_'):
+        if k in opt:
+            pass
+        elif k.startswith('_'):
             continue
-        if callable(v):
+        elif callable(v):
             continue
-        if k in base:
+        elif k in base:
             continue
-        if hasattr(msg_.__class__, k):
+        elif hasattr(msg_.__class__, k):
             continue
         yield (k, v)