Marshmallow plugin doesn't document the format of fields.DateTime() correctly

[TheBigRoomXXL]

Marshmallow support multiple format for DateTime:

format: Either "rfc" (for RFC822), "iso" (for ISO8601), "timestamp", "timestamp_ms" (for a POSIX timestamp) or a date format string. If None, defaults to “iso”.

I was expecting apispec to adapt documentation base on the format but apispec always default to iso format. To change this behavior , I guess the FieldConverterMixin.field2type_and_format would need to be changed but I don't know exactly how.

I don't know if that qualify as a "bug" but it would certainly be nice to have that in the future.

[lafrech]

Yes, in OpenAPI "date-time" implies iso and other formats should use a specific pattern.

https://stackoverflow.com/a/49379235

Let's label this a bug.

This deserves a new field2datetime function in field_converter.py.

Help on this welcome.

Hopefully the correct regex for other formats can be found somewhere.

Users using custom format would have to define the regex themselves.

[TheBigRoomXXL]

Yes, in OpenAPI "date-time" implies iso and other formats should use a specific pattern.

Yes but timestamp is a little different than custom date because it should have the type "integer" instead of "string".
Also OpenAPI format is an open field so I think we should also add 'timestamp' or 'timestamp_ms' as format .

Hopefully the correct regex for other formats can be found somewhere.

I couldn't find any regex for RFC822 so I did my own:

^((Mon|Tue|Wed|Thu|Fri|Sat|Sun), ){0,1}\d{2} (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) \d{4} \d{2}:\d{2}:\d{2} (UT|GMT|EST|EDT|CST|CDT|MST|MDT|PST|PDT|(Z|A|M|N)|(\+|-)\d{4})$

Some example of it here: https://regex101.com/r/hOctM6/1

It's not perfect. Some DateTime string not conform with RFC822 will slip through but it's very descriptive and relatively short..

Users using custom format would have to define the regex themselves.

Yes. I think a pattern parameter inside the metadata of field is a good place to put it.

Help on this welcome.

Here is my pull request : #815. I hope it's good with you!

[sloria]

resolved by #815 and released in 6.4.0