REST API: Add action-delete flag to declare delete_post capability for post objects

[ocean90]

Previously: #44287

To allow REST API clients to display a delete link for posts in their UI based on current user's capabilities we should provide an action-delete flag similar to the existing actions like action-publish.

One consumer would be the block editor as reported in ​https://github.com/WordPress/gutenberg/issues/23144.

[TimothyBlynJacobs]

Why can't this be discovered through the Allow header?

Trac ticket: https://core.trac.wordpress.org/ticket/50388

[ocean90]

Replying to TimothyBlynJacobs:

Why can't this be discovered through the Allow header?

Haven't seen your comment until now but indeed, the Allow header can be used and was actually implemented via ​https://github.com/WordPress/gutenberg/pull/23174.

Superseded by ​https://github.com/WordPress/gutenberg/pull/23174.

[swissspidy]

@TimothyBlynJacobs @ocean90 The Allow header works for wp/v2/posts/<id> requests. But what if I fetch a list of posts from wp/v2/posts/ and for each item want to know whether I can delete it?

[TimothyBlynJacobs]

We should implement targetHints, ​https://tools.ietf.org/id/draft-handrews-json-schema-hyperschema-00.html#rfc.section.6.5.5. Essentially we'd add something like this to self links.

{
  "self": [
    {
      "href": "https://example.org/wp-json/wp/v2/posts/1",
      "targetHints": {
        "allow": [
          "GET",
          "PUT",
          "DELETE"
        ]
      }
    }
  ]
}

Another use case: #41740.

[swissspidy]

That'd work I think! Does this warrant a new ticket or reopening this one?

[TimothyBlynJacobs]

Awesome! I think a new ticket for adding targetHints would make sense.