When choosing datetimes, ensure that time is relative to user's timezone

[mcdonc]

Might need to make a new schema node type based on colander.DateTime that automatically sets the tzinfo to the user's timezone, and returns a datetime converted to UTC.

[hirokiky]

Now the /index.atom of demo blog app causes Error on my enviroment. it is mainly due to this issue, right?

2014-04-23 18:18:59,630 ERROR [waitress][Dummy-2] Exception when serving /index.atom
Traceback (most recent call last):
  ...
  File "/Users/hirokiky/dev/substanced-blog/substanced-blog/blog/views/retail.py", line 224, in blog_atom
    feed, blogentries = self._get_feed_info()
  File "/Users/hirokiky/dev/substanced-blog/substanced-blog/blog/views/retail.py", line 197, in _get_feed_info
    _add_updated_strings(updated, info)
  File "/Users/hirokiky/dev/substanced-blog/substanced-blog/blog/views/retail.py", line 183, in _add_updated_strings
    info['updated_atom'] = updated.astimezone(pytz.utc).isoformat()
ValueError: astimezone() cannot be applied to a naive datetime

[hirokiky]

I created DateTime SchemaNode and Widget handling timezone. https://github.com/hirokiky/substanced/commit/b913502d3f367e0cfe5eac2dafa3a7bc7635fcf2

• Client users' timezone will be applied at the first time.
• Users can change the value
• If changing existing data, the default value of timezone input will be filled by the data

Like this

Thinking...

• This feature should be separated from substanced, and included in deform
• TimeZone should not be appeared by default
  • config-able would be nice

Special thanks for tsearver for giving some advices at PloneSymposiumTokyo Sprint.

[cguardia]

I'd say if it's generally useful, try to make a PR to deform. I agree that it's best if it doesn't appear by default. Maybe if configured to not show time zone, get it from the user's system by default.

[mcdonc]

I'd suggest putting it in Substance D right now and backporting it to deform later to be honest. I'm sure it's generally useful enough to add to deform but I dont anticipate a new deform release any time soon.

[tseaver]

I like the notion of a show_timezone option for the widget (defaulting to false, I think).

[hirokiky]

Thank you.

anyway now I noticed User has timezone property. Did @mcdonc say to use this value? My changes uses timezone info from browser (JavaScript). I feel user.timezone is better. Ofcause users are not logged in for all of times..

[hirokiky]

I fixed the code

1. Use user.timezone if logged in
2. Use browser timezone

And made it switchable to show or not.

[hirokiky]

PR Opened!