add class to load PaNOSC mappings into the code #265

datagateway_api/src/common/exceptions.py

@@ -53,3 +53,9 @@ class PythonICATError(ApiError):
     def __init__(self, msg="Python ICAT error", *args, **kwargs):
         super().__init__(msg, *args, **kwargs)
         self.status_code = 500
+
+
+class SearchAPIError(ApiError):
+    def __init__(self, msg="Search API error", *args, **kwargs):
+        super().__init__(msg, *args, **kwargs)
+        self.status_code = 500

datagateway_api/src/search_api/panosc_mappings.py

@@ -0,0 +1,29 @@
+import json
+from pathlib import Path
+
+from datagateway_api.src.common.exceptions import SearchAPIError
+
+
+class PaNOSCMappings:
+    def __init__(
+        self, path=Path(__file__).parent.parent.parent / "search_api_mapping.json",
+    ):
+        try:
+            with open(path, encoding="utf-8") as target:
+                self.mappings = json.load(target)
+        except IOError as e:
+            raise SearchAPIError(e)
+
+
+# TODO - don't think I'll need this
+def load_mappings(path=Path(__file__).parent.parent.parent / "search_api_mapping.json"):
+    try:
+        with open(path, encoding="utf-8") as target:
+            data = json.load(target)
+    except IOError as e:
+        raise SearchAPIError(e)
+
+    return data
+
+
+mappings = PaNOSCMappings()