Placeholder support for fields

[bdot]

- Do you want to request a feature or report a bug?

This is a feature request

- What is the current behavior?
Currently placeholders are not supported at field level. That is we can have a slug something like below at collection level but it doesn't work if used at field level.

slug: "{{year}}-{{month}}-{{day}}-{{slug}}"

- What is the expected behavior?
For example having a Field definition:

- {label: "Slug", name: "slug", widget: "hidden", default: "{{slug}}"}

Should produce an entry in the actual document body
Expected outcome in the body for an article titled "Netlify CMS is awesome" should be

slug: netlify-cms-is-awesome

[erquhart]

The slug placeholder is very specific to slugs - maybe we should consider just putting slugs in the frontmatter? Not certain if that would negatively affect various build tools.

The ability to edit slugs is covered under #445.

[dardub]

In Gatsby it's very common pattern to use the slug in the frontmatter. Right now I think we have to create the slug independently to use in Gatsby.

So adding the slug to frontmatter in some way would help Gatsby integration at the very least.

Edit:

I think in the use-case for gatsby. Allowing the use of template placeholders would be helpful.

So for a news collection I may want a field with the path 'news/{{slug}}'.
But for a gallery collection I may want the path 'gallery/{{slug}}'.

[anarchivist]

Slugs in frontmatter is also common for Jekyll; see https://jekyllrb.com/docs/permalinks/#template-variables for more details.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[martinjagodic]

Closing as stale and/or outdated.