refactor: small refactors based on PR review comments #260

datagateway_api/src/api_start_utils.py

@@ -12,7 +12,7 @@
 # Only attempt to create a DataGateway API backend if the datagateway_api object
 # is present in the config. This ensures that the API does not error on startup
 # due to an AttributeError exception being thrown if the object is missing.
-if Config.config.datagateway_api is not None:
+if Config.config.datagateway_api:
     from datagateway_api.src.datagateway_api.backends import create_backend
 from datagateway_api.src.datagateway_api.database.helpers import db  # noqa: I202
 from datagateway_api.src.datagateway_api.icat.icat_client_pool import create_client_pool
@@ -27,13 +27,15 @@
 from datagateway_api.src.resources.non_entities.sessions_endpoints import (
     session_endpoints,
 )
-from datagateway_api.src.resources.search_api_endpoints import (
-    get_files_endpoint,
-    get_number_count_endpoint,
-    get_number_count_files_endpoint,
-    get_search_endpoint,
-    get_single_endpoint,
-)
+
+if Config.config.search_api:
+    from datagateway_api.src.resources.search_api_endpoints import (
+        get_files_endpoint,
+        get_number_count_endpoint,
+        get_number_count_files_endpoint,
+        get_search_endpoint,
+        get_single_endpoint,
+    )
 from datagateway_api.src.resources.table_endpoints.table_endpoints import (
     count_instrument_facility_cycles_endpoint,
     count_instrument_investigation_endpoint,

datagateway_api/src/search_api/panosc_mappings.py

@@ -1,7 +1,9 @@
 import json
 import logging
 from pathlib import Path
+import sys
 
+from datagateway_api.src.common.config import Config
 from datagateway_api.src.common.exceptions import SearchAPIError
 
 log = logging.getLogger()
@@ -17,7 +19,12 @@ def __init__(
                 log.info("Loading PaNOSC to ICAT mappings from %s", path)
                 self.mappings = json.load(target)
         except IOError as e:
-            raise SearchAPIError(e)
+            # The API shouldn't exit if there's an exception (e.g. file not found) if
+            # the user is only using DataGateway API and not the search API
+            if Config.config.search_api:
+                sys.exit(
+                    f"An error occurred while trying to load the PaNOSC mappings: {e}",
+                )
 
     def get_panosc_related_entity_name(
         self, panosc_entity_name, panosc_related_field_name,

datagateway_api/src/search_api/query_filter_factory.py

@@ -141,21 +141,22 @@ def get_where_filter(where_filter_input, entity_name):
                     f", {e.args}",
                 )
 
-            try:
-                or_conditional_filters = []
-                field_names = entity_class._text_operator_fields
-                log.debug(
-                    "Text operators found for PaNOSC %s: %s", entity_name, field_names,
+            or_conditional_filters = []
+            field_names = entity_class._text_operator_fields
+            log.debug(
+                "Text operators found for PaNOSC %s: %s", entity_name, field_names,
+            )
+            if not field_names:
+                # No text operator fields present, simply log and move on, we should
+                # ignore text operator queries on entities where `_text_operator_fields`
+                # is empty (meaning they are not present in the origina PaNOSC data
+                # model)
+                log.info(
+                    "No text operator fields found for PaNOSC entity %s, will"
+                    " ignore",
+                    entity_name,
                 )
-                if not field_names:
-                    # No text operator fields present, raise KeyError to be caught in
-                    # this try/except block
-                    log.warning(
-                        "No text operator fields found for PaNOSC entity %s, will"
-                        " ignore",
-                        entity_name,
-                    )
-                    raise KeyError()
+            else:
                 for field_name in field_names:
                     or_conditional_filters.append(
                         {field_name: {"like": where_filter_input["text"]}},
@@ -169,11 +170,6 @@ def get_where_filter(where_filter_input, entity_name):
                         where_filter, entity_name,
                     ),
                 )
-            except KeyError:
-                # Do not raise FilterError nor attempt to create filters. Simply
-                # ignore text operator queries on fields that are not part of the
-                # text_operator_fields dict.
-                pass
         else:
             log.info("Basic where filter found, extracting field, value and operation")
             filter_data = SearchAPIQueryFilterFactory.get_condition_values(