Reordered middleware and tweaked docstrings

Co-authored-by: CasperWA <casper.andersen@epfl.ch>

optimade/server/exception_handlers.py

@@ -131,6 +131,8 @@ def general_exception_handler(request: Request, exc: Exception):
 To use these in FastAPI app code:
 
 ```python
+from fastapi import FastAPI
+app = FastAPI()
 for exception, handler in OPTIMADE_EXCEPTIONS:
     app.add_exception_handler(exception, handler)
 ```

optimade/server/main.py

@@ -85,13 +85,13 @@ def load_entries(endpoint_name: str, endpoint_collection: MongoCollection):
     for name, collection in ENTRY_COLLECTIONS.items():
         load_entries(name, collection)
 
-# Add required OPTIMADE middleware
+# Add CORS middleware first
+app.add_middleware(CORSMiddleware, allow_origins=["*"])
+
+# Then add required OPTIMADE middleware
 for middleware in OPTIMADE_MIDDLEWARE:
     app.add_middleware(middleware)
 
-# Add additional CORS middleware
-app.add_middleware(CORSMiddleware, allow_origins=["*"])
-
 # Add exception handlers
 for exception, handler in OPTIMADE_EXCEPTIONS:
     app.add_exception_handler(exception, handler)

optimade/server/main_index.py

@@ -83,13 +83,13 @@
 
     LOGGER.debug("Done inserting index links!")
 
-# Add required OPTIMADE middleware
+# Add CORS middleware first
+app.add_middleware(CORSMiddleware, allow_origins=["*"])
+
+# Then add required OPTIMADE middleware
 for middleware in OPTIMADE_MIDDLEWARE:
     app.add_middleware(middleware)
 
-# Add additional CORS middleware
-app.add_middleware(CORSMiddleware, allow_origins=["*"])
-
 # Add exception handlers
 for exception, handler in OPTIMADE_EXCEPTIONS:
     app.add_exception_handler(exception, handler)

optimade/server/middleware.py

@@ -471,6 +471,8 @@ async def dispatch(self, request: Request, call_next):
 To use these in FastAPI app code:
 
 ```python
+from fastapi import FastAPI
+app = FastAPI()
 for middleware in OPTIMADE_MIDDLEWARE:
     app.add_middleware(middleware)
 ```