xdd: Implement option to load object dictionary from XDD file.

Signed-off-by: Taras Zaporozhets <zaporozhets.taras@gmail.com>

Author: zaporozhets

canopen/objectdictionary/__init__.py

@@ -76,7 +76,7 @@ def import_od(
     source: Union[str, TextIO, None],
     node_id: Optional[int] = None,
 ) -> ObjectDictionary:
-    """Parse an EDS, DCF, or EPF file.
+    """Parse an EDS, DCF, EPF or XDD file.
 
     :param source:
         The path to object dictionary file, a file like object, or an EPF XML tree.
@@ -106,9 +106,12 @@ def import_od(
     elif suffix == ".epf":
         from canopen.objectdictionary import epf
         return epf.import_epf(source)
+    elif suffix == ".xdd":
+        from canopen.objectdictionary import xdd
+        return xdd.import_xdd(source, node_id)
     else:
         doc_type = suffix[1:]
-        allowed = ", ".join(["eds", "dcf", "epf"])
+        allowed = ", ".join(["eds", "dcf", "epf", "xdd"])
         raise ValueError(
             f"Cannot import from the {doc_type!r} format; "
             f"supported formats: {allowed}"

canopen/objectdictionary/eds.py

@@ -9,6 +9,7 @@
 from canopen import objectdictionary
 from canopen.objectdictionary import ObjectDictionary, datatypes
 from canopen.sdo import SdoClient
+from canopen.utils import signed_int_from_hex, calc_bit_length
 
 if TYPE_CHECKING:
     import canopen.network
@@ -201,30 +202,6 @@ def import_from_node(node_id: int, network: canopen.network.Network):
         network.unsubscribe(0x580 + node_id)
     return od
 
-
-def _calc_bit_length(data_type):
-    if data_type == datatypes.INTEGER8:
-        return 8
-    elif data_type == datatypes.INTEGER16:
-        return 16
-    elif data_type == datatypes.INTEGER32:
-        return 32
-    elif data_type == datatypes.INTEGER64:
-        return 64
-    else:
-        raise ValueError(f"Invalid data_type '{data_type}', expecting a signed integer data_type.")
-
-
-def _signed_int_from_hex(hex_str, bit_length):
-    number = int(hex_str, 0)
-    max_value = (1 << (bit_length - 1)) - 1
-
-    if number > max_value:
-        return number - (1 << bit_length)
-    else:
-        return number
-
-
 def _convert_variable(node_id, var_type, value):
     if var_type in (datatypes.OCTET_STRING, datatypes.DOMAIN):
         return bytes.fromhex(value)
@@ -288,7 +265,7 @@ def build_variable(eds, section, node_id, index, subindex=0):
         try:
             min_string = eds.get(section, "LowLimit")
             if var.data_type in datatypes.SIGNED_TYPES:
-                var.min = _signed_int_from_hex(min_string, _calc_bit_length(var.data_type))
+                var.min = signed_int_from_hex(min_string, calc_bit_length(var.data_type))
             else:
                 var.min = int(min_string, 0)
         except ValueError:
@@ -297,7 +274,7 @@ def build_variable(eds, section, node_id, index, subindex=0):
         try:
             max_string = eds.get(section, "HighLimit")
             if var.data_type in datatypes.SIGNED_TYPES:
-                var.max = _signed_int_from_hex(max_string, _calc_bit_length(var.data_type))
+                var.max = signed_int_from_hex(max_string, calc_bit_length(var.data_type))
             else:
                 var.max = int(max_string, 0)
         except ValueError:

canopen/utils.py

@@ -1,7 +1,7 @@
 """Additional utility functions for canopen."""
 
 from typing import Optional, Union
-
+from canopen.objectdictionary import datatypes
 
 def pretty_index(index: Optional[Union[int, str]],
                  sub: Optional[Union[int, str]] = None):
@@ -21,3 +21,24 @@ def pretty_index(index: Optional[Union[int, str]],
         sub_str = f"{sub!r}"
 
     return ":".join(s for s in (index_str, sub_str) if s)
+
+def signed_int_from_hex(hex_str, bit_length):
+    number = int(hex_str, 0)
+    max_value = (1 << (bit_length - 1)) - 1
+
+    if number > max_value:
+        return number - (1 << bit_length)
+    else:
+        return number
+    
+def calc_bit_length(data_type):
+    if data_type == datatypes.INTEGER8:
+        return 8
+    elif data_type == datatypes.INTEGER16:
+        return 16
+    elif data_type == datatypes.INTEGER32:
+        return 32
+    elif data_type == datatypes.INTEGER64:
+        return 64
+    else:
+        raise ValueError(f"Invalid data_type '{data_type}', expecting a signed integer data_type.")