video-ids output format for list cmd

[itscaro]

Description

Maybe useful to avoid using jq to reformat.

Usage could be:

./youtubedr download $(./youtubedr list <playlistID> --format video-ids)

# or

./youtubedr list <playlistID> --format video-ids | ./youtubedr download

Issues to fix

Please link issues this PR will fix:
#[issue number]

if no relevant issue, but this will fix something important for reference
, please free to open an issue.

Reminding

Something you can do before PR to reduce time to merge

• run "make build" to build the code
• run "make format" to reformat the code
• run "make lint" if you are using unix system
• run "make test-integration" to pass all tests

[itscaro]

the flag is handled by addFormatFlag which prints 4 formats. For info cmd, this new format is not implemented. Maybe when info cmd accepts multiple URLs we can extract all video IDs the same way as list cmd does in this PR?

./youtubedr-dev info <videoID> --format video-ids
unhandled output format: video-ids

./youtubedr-dev list <playlistID> --format video-ids
JTRqppn4vNo lhbytXY9gEs 7Y7m3uMRNak GjhRMetsok0 fePN2EFK5bU 7sX44EkgTds sAb-ogxZIAI kv-8SeTfT0k CHvhcM_Rvlo -075jrjea4Q ZgHrrkG175M KK58lRTSn5I iIfgwENiL3o VNNXO4DIHUo

[corny]

Which problem does this pull request solve? Do you want to download all videos of a playlist?

[itscaro]

This PR tries to export directly a list of IDs separated by space, which can be piped into other tools. Download a playlist is one of the goals, this can be (and I would like to propose a PR) done in download cmd, if it detects a playlist then it will download all media from playlist.

The format video-ids is intended for a broader usage, maybe someone wants do sth with other tools? This format could be used to extract video id in info cmd too.

Currently I used this command after list cmd is implemented

 youtubedr list <playlistID> --format json | jq '.Videos[].ID' | xargs -r youtubedr download

Feel free to decline the PR @corny

[corny]

What do you think about adding CSV as output format and optionally selecting the columns? If you want all video IDs, you can just select the videoID column and skip the first line (column header).

[itscaro]

Video IDs
<ID1> <ID2>

Like this? nice idea. I'll change the PR this wk.
Do you have an idea how to pass arg to choose column to keep it simple?

[corny]

It's better to have column headers without spaces. Example:

$ youtubedr list --format csv --csv-columns video_id,title <playlistID>
video_id,title
id1,title2
id2,"title with space"

Or just IDs without headers:

$ youtubedr list --format csv --csv-columns video_id, --csv-headers false <playlistID>
id1
id2

Just use NewWriter() from the encoding/csv package.