Enhancement: import agenda from CSV

[michaelmhoffman]

I often need to do bulk editing of my calendar which is not super convenient with the Google Calendar web interface. A spreadsheet interface would be much better.

What would you think about a way to do roundtrip updates through gcalcli agenda --tsv and a paired command agendaupdate for writing any changes back? We would need:

• [x] Some refactoring of gcalcli.gcal.GoogleCalendarInterface._tsv(). I would like to replace the current long list of if statements with a modular design based around new class gcalcli.details.Handler. Each Handler represents the set of event properties that are captured by each item of gcalcli.argparsers.DETAILS. These objects would have get() handlers for TSV. They would be stored in a collections.OrderedDict called gcalcli.details.HANDLERS.
• [x] Set gcalcli.argparsers.DETAILS to a superset of gcalcli.details.HANDLERS.keys() to avoid duplication.
• [x] Add a header row to TSV. This would probably break old code so would require a major release. The alternative would be to add an option like --header.
• [x] Implement a Handler for id to make it trivial to find the right Event later for the round trip.
• [x] Implement Handler.patch() for a limited set of details. Throw error if there is a column not in the implemented set.
• [x] Implement Handler.patch() for the rest of the details.

Future extensions or subsequent refactoring could include:

• Refactoring other uses of patch to call details.Handler subclasses
• Add Detail.format() handlers that could be used for gcalcli.gcal.GoogleCalendarInterface._PrintEvent().
• A feature to add new events through this interface instead of only updating events with existing IDs (#550)
• Adding ability to support multiple calendars in agendaupdate
• Adding ability to move events between calendars by changing the calendar field (see commit message for d7589edbdcdf60872179a8be47d7e6b0452ed287)
• A feature to do the round-trip through a Google Sheets instead of a local TSV

[michaelmhoffman]

@jcrowgey Could you let me know what you think of this design?

[jcrowgey]

Overall this looks good to me. Your recent work on this project has been very helpful and appreciated. I'm sorry for the long delays. In general, I'm not going to be able to work on gcalcli much for the foreseeable future.

On Mon, Jul 27, 2020 at 03:15:57PM -0700, Michael Hoffman wrote:

@jcrowgey Could you let me know what you think of this design?

-- You are receiving this because you were mentioned. Reply to this email directly or view it on GitHub: https://github.com/insanum/gcalcli/issues/550#issuecomment-664665671

[michaelmhoffman]

To get the TSV output of gcalcli agenda to work automatically in Microsoft Excel with non-ASCII characters, it is necessary to set PYTHONIOENCODING=utf_16. Things that don't work utf_16_le (no BOM) or utf_8_sig (BOM but for whatever reason Excel ignores the tabs by default). This does not seem like a sensible default but if you intend to use these files with Excel you should know about it.

[michaelmhoffman]

The easiest way to use a UTF-16 file.tsv is to use input redirection with the PYTHONIOENCODING environment variable set. There's no user-accessible way to change the encoding of what's read with a file argument.

PYTHONIOENCODING=utf_16 gcalcli agendaupdate < file.tsv

[michaelmhoffman]

The output of PYTHONIOENCODING=utf_16 gcalcli agenda isn't easy to use some other Unix tools like grep with. Instead you can use iconv --to-code=utf-16 as part of a pipeline. For example:

gcalcli agenda | grep Title | iconv --to-code=utf-16 > file.csv