Add option to make "cobalt publish" add date prefix to filename

[Geobert]

To keep files in order by chronology, it would be cool to add the YYYY-MM-DD- prefix to the filename on cobalt publish

Proposal

Activation by a configuration field in _cobalt.yml:

posts:
  publish_date_in_filename: true

Default:

• publish_date_in_filename true for posts
• publish_date_in_filename false for pages

cobalt publish behavior:

• Add or update date prefix on file name
• Set or update published_date in frontmatter

Impact on inferring published_date from filename

For now, we will unconditionally still infer the date from the filename.

• Not everyone will be using cobalt publish
• Until we have Collections (RFC Add Collections support. #368), we sometimes have to imitate it.

An open question for later is whether we should make the inferring of the date exclusive to this flag being enabled. That question is irrelevant until we have Collections support.

[epage]

posts:
  add_date_prefix: true

We need to consider what name makes the intent clear. This name doesn't help us know it is scoped to cobalt publish or that it is the published_date.

We can also look at re-framing the problem. We could instead consider a flag to enable extracting the published_date from the filename and if it is enabled, then cobalt publish also prepends it.

[epage]

I tweaked it some to try to make it more explicit. Feel free to update it if I misunderstood

if date present in filename, put it in published_date, adding time only

What happens if the existing date is not the current date?

If cobalt publish is setting published_date, do we still maintain the date extraction logic or just detect it and strip it?

[epage]

I've updated the RFC with my proposal on inferring published_date from filename. It is based on my recent experience of putting my meetup talks on my site. The ideal is that I have a talks collection that parallels my blog collection. Since we can't do that ideal yet, I'm part-way doing things by having dates on regular pages.

See https://github.com/epage/epage.github.io/tree/source/blog/talks

[Geobert]

Just to be sure, the flag to activate is still publish_date_in_filename and not add-date-prefix as stated in the commit message? I've checked master, and it seems to be publish_date_in_filename.

[Geobert]

Tried to use it, for some reason my file is not considered in the posts collection. So it does not trigger the prefixing.

My blog is like this:

blog
  |
  -- src
        |
        -- posts
              |
              -- my_post.md

I'm in blog and call cobalt publish ./src/posts/my_post.md
The file get the published status and the published_date set, but no renaming. Adding some traces shows that my_post.md is not inside the collection :-/

What am I missing?

EDIT:
added more traces, it seems that includes_file got an absolute path in self.subtree whereas I have a relative path for file.

I don't know how I missed this, the only think I can see is that I didn't test after adding checking the collection… so dumb me…

file: ".\\src\\posts\\my_post.md"
subtree: "I:\\Dev\\blog\\src\\posts"

EDIT2: fixed with #587

[epage]

Just to be sure, the flag to activate is still publish_date_in_filename and not add-date-prefix as stated in the commit message? I've checked master, and it seems to be publish_date_in_filename.

I didn't pay attention when rewriting the commit message, I just took from the existing commit message.

[epage]

EDIT2: fixed with #587

Thanks! Will go and look at it.