issue_comments

Rough initial prototype: ```diff diff --git a/datasette/views/table.py b/datasette/views/table.py index 8b987221..518ac578 100644 --- a/datasette/views/table.py +++ b/datasette/views/table.py @@ -1103,19 +1103,30 @@ class TableInsertView(BaseView): except json.JSONDecodeError as e: return _errors(["Invalid JSON: {}".format(e)]) if not isinstance(data, dict): - return _errors(["JSON must be a dictionary"]) + return _errors([{"detail": "JSON must be a dictionary", "pointer": "#/"}]) keys = data.keys()

     # keys must contain "row" or "rows"
     if "row" not in keys and "rows" not in keys:
         return _errors(['JSON must have one or other of "row" or "rows"'])
     rows = []

• was_single_row = False if "row" in keys: if "rows" in keys:
• return _errors(['Cannot use "row" and "rows" at the same time'])
• return _errors(
• [
• {
• "detail": 'Cannot use "row" and "rows" at the same time',
• "pointer": "#/row",
• }
• ]
• )
• was_single_row = True row = data["row"] if not isinstance(row, dict):
• return _errors(['"row" must be a dictionary'])
• return _errors(
• [{"detail": '"row" must be a dictionary', "pointer": "#/row"}]
• ) rows = [row] data["return"] = True else: @@ -1152,9 +1163,12 @@ class TableInsertView(BaseView): invalid_columns = set(row.keys()) - columns if invalid_columns: errors.append(
• "Row {} has invalid columns: {}".format(
• i, ", ".join(sorted(invalid_columns))
• )
• {
• "detail": "Invalid columns: {}".format(
• ", ".join(sorted(invalid_columns))
• ),
• "pointer": "#/blah/",
• } ) if errors: return _errors(errors) ```

Worth noting this bit in RFC 7807:

The fictional problem type here defines the "errors" extension, an array that describes the details of each validation error. Each member is an object containing "detail" to describe the issue, and "pointer" to locate the problem within the request's content using a JSON Pointer [JSON-POINTER].

So the list of "errors" with JSON Pointer isn't technically part of the spec, it's an imaginary extension.

It fits what I need to do though, so I'm inclined to stick with it anyway.

TIL: https://til.simonwillison.net/json/json-pointer

Spec looks pretty simple:

A JSON Pointer is a Unicode string (see [RFC4627], Section 3) containing a sequence of zero or more reference tokens, each prefixed by a / (%x2F) character.

Because the characters ~ (%x7E) and / (%x2F) have special meanings in JSON Pointer, ~ needs to be encoded as ~0 and / needs to be encoded as ~1 when these characters appear in a reference token.

That's using JSON Pointer: https://www.rfc-editor.org/rfc/rfc6901

There's a Python library for that here https://github.com/stefankoegl/python-json-pointer/blob/master/jsonpointer.py - which looks simple and clean and well maintained and documented, but it only handles the "what is at this pointer within this JSON object" case - I need to generate the correct JSON pointer to explain where my error is.

So I think I'll end up hand-rolling this.

Here's the most relevant example from the RFC spec: POST /details HTTP/1.1 Host: account.example.com Accept: application/json json { "age": 42.3, "profile": { "color": "yellow" } } HTTP/1.1 400 Bad Request Content-Type: application/problem+json Content-Language: en json { "type": "https://example.net/validation-error", "title": "Your request is not valid.", "errors": [ { "detail": "must be a positive integer", "pointer": "#/age" }, { "detail": "must be 'green', 'red' or 'blue'", "pointer": "#/profile/color" } ] }

I started a conversation about JSON error standards on Mastodon here: https://fedi.simonwillison.net/web/@simon/109338725610487457

Quite a few people pointed to this RFC independently.