fix: improve unusual error handling for api/chart/data

I've recently encountered some errors on the dashboard page, within Chart widgets where html is displayed as a result of calling the `api/chart/data` endpoint, and presumably while hitting some 502 / 504s-type error. The error is hard to reproduce, but I'm thinking the approach bellow should improve / prevent that endpoint from ever returning html.

Two changes here:
- sprinkling the @handle_api_error decorator in critical related views
- improving the 500 flask error handler to be a bit smarter, hoping it'll catch some of the problems and return json when expecting it

superset/charts/data/api.py

@@ -52,7 +52,12 @@
     get_user_id,
 )
 from superset.utils.decorators import logs_context
-from superset.views.base import CsvResponse, generate_download_headers, XlsxResponse
+from superset.views.base import (
+    CsvResponse,
+    generate_download_headers,
+    handle_api_exception,
+    XlsxResponse,
+)
 from superset.views.base_api import statsd_metrics
 
 if TYPE_CHECKING:
@@ -71,6 +76,7 @@ class ChartDataRestApi(ChartRestApi):
         action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.data",
         log_to_statsd=False,
     )
+    @handle_api_exception
     def get_data(self, pk: int) -> Response:
         """
         Take a chart ID and uses the query context stored when the chart was saved
@@ -184,6 +190,7 @@ def get_data(self, pk: int) -> Response:
         action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.data",
         log_to_statsd=False,
     )
+    @handle_api_exception
     def data(self) -> Response:
         """
         Take a query context constructed in the client and return payload
@@ -224,6 +231,7 @@ def data(self) -> Response:
               $ref: '#/components/responses/500'
         """
         json_body = None
+
         if request.is_json:
             json_body = request.json
         elif request.form.get("form_data"):
@@ -269,6 +277,7 @@ def data(self) -> Response:
         f".data_from_cache",
         log_to_statsd=False,
     )
+    @handle_api_exception
     def data_from_cache(self, cache_key: str) -> Response:
         """
         Take a query context cache key and return payload

superset/views/base.py

@@ -522,6 +522,7 @@ def show_command_errors(ex: CommandException) -> FlaskResponse:
 
 # Catch-all, to ensure all errors from the backend conform to SIP-40
 @superset_app.errorhandler(Exception)
+@superset_app.errorhandler(500)
 def show_unexpected_exception(ex: Exception) -> FlaskResponse:
     logger.exception(ex)
     if "text/html" in request.accept_mimetypes and not config["DEBUG"]:

superset/views/core.py

@@ -23,7 +23,7 @@
 from typing import Any, Callable, cast
 from urllib import parse
 
-from flask import abort, flash, g, redirect, render_template, request, Response
+from flask import abort, flash, g, redirect, request, Response
 from flask_appbuilder import expose
 from flask_appbuilder.security.decorators import (
     has_access,
@@ -85,7 +85,6 @@
     data_payload_response,
     deprecated,
     generate_download_headers,
-    get_error_msg,
     handle_api_exception,
     json_error_response,
     json_success,
@@ -886,13 +885,6 @@ def fetch_datasource_metadata(self) -> FlaskResponse:
         datasource.raise_for_access()
         return json_success(json.dumps(sanitize_datasource_data(datasource.data)))
 
-    @app.errorhandler(500)
-    def show_traceback(self) -> FlaskResponse:
-        return (
-            render_template("superset/traceback.html", error_msg=get_error_msg()),
-            500,
-        )
-
     @event_logger.log_this
     @expose("/welcome/")
     def welcome(self) -> FlaskResponse: