Added json conversion according to REC2021-10-13

https://www.xbrl.org/Specification/xbrl-json/REC-2021-10-13/xbrl-json-REC-2021-10-13.html

Author: manusimidt

xbrl/instance.py

@@ -191,25 +191,19 @@ def __str__(self) -> str:
 
     def json(self, **kwargs) -> dict:
         if isinstance(self.context, TimeFrameContext):
-            start_date = self.context.start_date
-            end_date = self.context.end_date
+            period: str = f"{self.context.start_date}/{self.context.end_date}"
         elif isinstance(self.context, InstantContext):
-            start_date = self.context.instant_date
-            end_date = self.context.instant_date
+            period: str = str(self.context.instant_date)
         else:
-            start_date = '',
-            end_date = ''
+            period: str = ''  # Forever context not specified in REC-2021-10-13
 
         kwargs['value'] = self.value
-        kwargs['start_date'] = str(start_date)
-        kwargs['end_date'] = str(end_date)
-        kwargs["taxonomy"] = self.concept.schema_url
-        kwargs['concept'] = self.concept.name
-        kwargs["entity"] = self.context.entity
-        if len(self.context.segments) != 0:
-            kwargs['dimensions'] = []
-            for segment in self.context.segments:
-                kwargs['dimensions'].append({"axis": segment.dimension.name, "member": segment.member.name})
+        if 'dimensions' not in kwargs: kwargs['dimensions'] = {}
+        kwargs['dimensions']['concept'] = self.concept.name
+        kwargs['dimensions']['entity'] = self.context.entity
+        kwargs['dimensions']['period'] = period
+        for segment in self.context.segments:
+            kwargs['dimensions'][segment.dimension.name] = segment.member.name
         return kwargs
 
 
@@ -236,7 +230,7 @@ def __init__(self, concept: Concept, context: AbstractContext, value: float or N
         self.decimals: int or None = decimals
 
     def json(self) -> dict:
-        return super().json(unit=str(self.unit))
+        return super().json(dimensions={"unit": str(self.unit)}, decimals=self.decimals)
 
 
 class TextFact(AbstractFact):
@@ -292,26 +286,26 @@ def __str__(self) -> str:
         file_name: str = self.instance_url.split('/')[-1]
         return "{} with {} facts".format(file_name, len(self.facts))
 
-    def json(self, file_path: str = None) -> str or None:
+    def json(self, file_path: str = None, override_fact_ids: bool = True) -> str or None:
         """
         Converts the instance document into json format
         :param file_path: if a path is given the function will store the json there
+        :param override_fact_ids:
         :return: string (serialized json) or None (if file_path was given)
 
-        https://www.xbrl.org/Specification/xbrl-json/CR-2017-05-02/xbrl-json-CR-2017-05-02.html
-        https://www.xbrl.org/Specification/xbrl-json/CR-2021-07-07/xbrl-json-CR-2021-07-07.html
-        These two xbrl-json specification drafts are very different.
-        The latter uses fact_id as keys in the fact dictionary. However many older reports have no fact id's.
-        Additionally fact ids of iXBRL documents can be really really ugly (Hashes concatenated with UUIDs).
-        Therefore i will design my own JSON structure until the Specification is finalized by XBRL International.
+        https://www.xbrl.org/Specification/xbrl-json/REC-2021-10-13/xbrl-json-REC-2021-10-13.html
         """
         json_dict: dict = {
-            "instance_url": self.instance_url,
-            "taxonomy_urls": self.taxonomy.get_schema_urls(),
-            "facts": []
+            "facts": {},
+            "documentInfo": {
+                "documentType": "https://xbrl.org/2021/xbrl-json",
+                "taxonomy": self.taxonomy.get_schema_urls(),
+                "baseUrl": self.instance_url
+            }
         }
-        for fact in self.facts:
-            json_dict['facts'].append(fact.json())
+        for i, fact in enumerate(self.facts):
+            fact_id = fact.xml_id if fact.xml_id and not override_fact_ids else f'f{i}'
+            json_dict['facts'][fact_id] = fact.json()
         if file_path:
             with open('data.json', 'w') as f:
                 return json.dump(json_dict, f)