Add odata_compact_json decorator

TM1py/Services/CellService.py

@@ -24,7 +24,7 @@
 from TM1py.Services.ViewService import ViewService
 from TM1py.Utils import Utils, CaseAndSpaceInsensitiveSet, format_url, add_url_parameters
 from TM1py.Utils.Utils import build_pandas_dataframe_from_cellset, dimension_name_from_element_unique_name, \
-    CaseAndSpaceInsensitiveDict, wrap_in_curly_braces, CaseAndSpaceInsensitiveTuplesDict, abbreviate_mdx, \
+    CaseAndSpaceInsensitiveDict, extract_cell_properties_from_odata_context, map_cell_properties_to_data, wrap_in_curly_braces, CaseAndSpaceInsensitiveTuplesDict, abbreviate_mdx, \
     build_csv_from_cellset_dict, require_version, require_pandas, build_cellset_from_pandas_dataframe, \
     case_and_space_insensitive_equals, get_cube, resembles_mdx, require_admin
 
@@ -115,6 +115,54 @@ def wrapper(self, *args, **kwargs):
     return wrapper
 
 
+def odata_compact_json(return_props_with_data: Optional[bool] = True):
+    """ Higher order function to manage header and response when using compact JSON
+        
+        Applies when decorated function has `use_compact_json` argument set to True
+
+        Currently only supports responses with only cell properties and where they are explicitly specified:
+            * Cellsets('...')?$expand=Axes(...),Cells($select=Ordinal,Value...) does NOT work !
+            * Cellsets('...')?$expand=Cells does NOT work !
+            * Cellsets('...')?$expand=Cells($select=Ordinal,Value...) works !
+
+    """
+    def wrap(func):
+        @functools.wraps(func)
+        def wrapper(self, *args, **kwargs):
+            if kwargs.get("use_compact_json", False):
+                # Update Accept Header
+                header = self._rest.get_http_header('Accept')
+                parts = header.split(';')
+                # Point of insertion is important. Needs to come after application/json
+                parts.insert(1, 'tm1.compact=v0')
+                modified_header = ";".join(parts)
+                self._rest.add_http_header('Accept', modified_header)
+                try:
+                    response = func(self, *args, **kwargs)
+                    context = response['@odata.context']
+
+                    props = extract_cell_properties_from_odata_context(context)
+
+                    # First element [0] is the cellset ID, second is the cellset data
+                    data = response['value'][1]
+
+                    # return props with data if required
+                    if return_props_with_data:
+                        return map_cell_properties_to_data(props, data)
+
+                    if len(props) == 1:
+                        return [value[0] for value in data]
+
+                    return data
+                finally:
+                    # Restore original header
+                    self._rest.add_http_header('Accept', header)
+            else:
+                return func(self, *args, **kwargs)
+        return wrapper
+    return wrap
+
+
 class CellService(ObjectService):
     """ Service to handle Read and Write operations to TM1 cubes