look up different OSM types in placex separately

[nominatim.git] / src / nominatim_api / result_formatting.py

diff --git a/src/nominatim_api/result_formatting.py b/src/nominatim_api/result_formatting.py
index 572cd3cd3df7ec37c4a9ecba22b5cd9f5e4317fd..0f91b7610ec85fc44cbe58a91d4036b969171443 100644 (file)
--- a/src/nominatim_api/result_formatting.py
+++ b/src/nominatim_api/result_formatting.py
@@ -12,19 +12,25 @@ from collections import defaultdict
 from pathlib import Path
 import importlib
 
-T = TypeVar('T') # pylint: disable=invalid-name
+from .server.content_types import CONTENT_JSON
+
+T = TypeVar('T')
 FormatFunc = Callable[[T, Mapping[str, Any]], str]
+ErrorFormatFunc = Callable[[str, str, int], str]
 
 
 class FormatDispatcher:
-    """ Helper class to conveniently create formatting functions in
-        a module using decorators.
+    """ Container for formatting functions for results.
+        Functions can conveniently be added by using decorated functions.
     """
 
-    def __init__(self) -> None:
+    def __init__(self, content_types: Optional[Mapping[str, str]] = None) -> None:
+        self.error_handler: ErrorFormatFunc = lambda ct, msg, status: f"ERROR {status}: {msg}"
+        self.content_types: Dict[str, str] = {}
+        if content_types:
+            self.content_types.update(content_types)
         self.format_functions: Dict[Type[Any], Dict[str, FormatFunc[Any]]] = defaultdict(dict)
 
-
     def format_func(self, result_class: Type[T],
                     fmt: str) -> Callable[[FormatFunc[T]], FormatFunc[T]]:
         """ Decorator for a function that formats a given type of result into the
@@ -36,19 +42,24 @@ class FormatDispatcher:
 
         return decorator
 
+    def error_format_func(self, func: ErrorFormatFunc) -> ErrorFormatFunc:
+        """ Decorator for a function that formats error messges.
+            There is only one error formatter per dispatcher. Using
+            the decorator repeatedly will overwrite previous functions.
+        """
+        self.error_handler = func
+        return func
 
     def list_formats(self, result_type: Type[Any]) -> List[str]:
         """ Return a list of formats supported by this formatter.
         """
         return list(self.format_functions[result_type].keys())
 
-
     def supports_format(self, result_type: Type[Any], fmt: str) -> bool:
         """ Check if the given format is supported by this formatter.
         """
         return fmt in self.format_functions[result_type]
 
-
     def format_result(self, result: Any, fmt: str, options: Mapping[str, Any]) -> str:
         """ Convert the given result into a string using the given format.
 
@@ -57,6 +68,29 @@ class FormatDispatcher:
         """
         return self.format_functions[type(result)][fmt](result, options)
 
+    def format_error(self, content_type: str, msg: str, status: int) -> str:
+        """ Convert the given error message into a response string
+            taking the requested content_type into account.
+
+            Change the format using the error_format_func decorator.
+        """
+        return self.error_handler(content_type, msg, status)
+
+    def set_content_type(self, fmt: str, content_type: str) -> None:
+        """ Set the content type for the given format. This is the string
+            that will be returned in the Content-Type header of the HTML
+            response, when the given format is choosen.
+        """
+        self.content_types[fmt] = content_type
+
+    def get_content_type(self, fmt: str) -> str:
+        """ Return the content type for the given format.
+
+            If no explicit content type has been defined, then
+            JSON format is assumed.
+        """
+        return self.content_types.get(fmt, CONTENT_JSON)
+
 
 def load_format_dispatcher(api_name: str, project_dir: Optional[Path]) -> FormatDispatcher:
     """ Load the dispatcher for the given API.