fix(boolean-values): allow 0 and 1 as boolean values (DEV-251) (#131)

* allow 0 and 1 as boolean values

* add documentation

* remove complexity

* use f-string for error message

Author: irinaschubert

docs/dsp-tools-xmlupload.md

@@ -696,7 +696,7 @@ Attributes:
 
 #### `<boolean>`
 
-The `<boolean>` element must contain the string "true" or "false", or the numeral 1 or 0.
+The `<boolean>` element must contain the string "true" or "false", or the numeral 1 (true) or 0 (false).
 
 Attributes:
 

knora/dsplib/models/value.py

@@ -601,18 +601,17 @@ def __init__(self,
                  iri: Optional[str] = None,
                  ark_url: Optional[str] = None,
                  vark_url: Optional[str] = None):
+
         if type(value) is bool:
             self._value = value
-
-        elif type(value) is str:
-            if value.upper() == 'TRUE':
+        else:
+            if value == 1 or value.upper() == 'TRUE' or value == '1':
                 self._value = True
-            elif value.upper() == 'FALSE':
+            elif value == 0 or value.upper() == 'FALSE' or value == '0':
                 self._value = False
             else:
-                raise BaseError("Invalid boolean format! " + str(value))
-        elif type(value) is int:
-            self._value = False if value == 0 else True
+                raise BaseError(f"ERROR Invalid boolean format {value}!")
+
         super().__init__(iri=iri,
                          comment=comment,
                          permissions=permissions,