Incorrect formatting of _links on OPTIONS request to embedded collections

[nsundberg]

When sending an OPTIONS request to a non-variable route (eg. /wp/v2/posts) with ?_embed=true and WP_DEBUG enabled the following warning appears (example from 5.3.2):

Warning: Invalid argument supplied for foreach() in /wp-includes/rest-api/class-wp-rest-server.php on line 569

This is caused by the following lines which sets the link as a string instead of an associative array with a href key, like the embed_links method expects: class-wp-rest-server.php:L1216-L1218​

$data['_links'] = array(
  'self' => rest_url( $route ),
);

Expected:

$data['_links'] = array(
  'self' => array(
    'href' => rest_url( $route ),
  ),
);

Was about to submit a patch but when looking into it I got a bit unsure if the _links property even should be included in these responses. From what I can tell no other endpoints include the _links property in the response for OPTIONS requests, but please advise.

[TimothyBlynJacobs]

Thanks for the ticket @nsundberg!

I think it'd be best to fix the link to be an associate array as you suggested. I think it'd be a good separate enhancement to add those self links to the OPTIONS response.

[TimothyBlynJacobs]

Thanks for the patch @nsundberg. There should be another layer of a wrapping array around the wrapping you added. In other words, each relation should be an array of links, where each link is an array with an href key.

For example the following JSON is expected.

{
  "_links": {
    "self": [
      {
        "href": "https://"
      }
    ]
  }
}

[nsundberg]

Ah, sorry, didn't look close enough!

[TimothyBlynJacobs]

Thanks for the patch @nsundberg! Do you want to try tackling a ​unit test for this?

[johnwatkins0]

Adds unit test for the change attached earlier

[birgire]

Replying to TimothyBlynJacobs:

Thanks for the patch @nsundberg. There should be another layer of a wrapping array around the wrapping you added. In other words, each relation should be an array of links, where each link is an array with an href key.

For example the following JSON is expected.

{
  "_links": {
    "self": [
      {
        "href": "https://"
      }
    ]
  }
}

Hi, I was just wondering about the array wrappers for the self key.

I skimmed through:

​https://developer.wordpress.org/rest-api/using-the-rest-api/linking-and-embedding/

and

​http://stateless.co/hal_specification.html
​https://tools.ietf.org/html/draft-kelly-json-hal-08

but I didn't see a similar self array HAL examples there, just "self": { "href" :"https://..." }

So out of curiosity, is this self array wrapping a special WordPress implementation? Thanks.

[birgire]

Replying to johnwatkins0:

Thanks for the unit test in 49147.3.diff​.

I was just wondering about the GET method test there:

Shouldn't the OPTIONS method be targetted specifically here, according to the ticket's title?

ps: the @ticket 49147 annotation is missing in 49147.3.diff​ and array() should be used instead of the array alias [] according to the code standard.

[johnwatkins0]

Removed debug code left in previous atttachment

[johnwatkins0]

Thanks for looking, @birgire . I've added 49147.5.diff with updates based on your feedback.

[TimothyBlynJacobs]

@birgire We don't treat self special, the REST API allows for any link relation to have multiple links for it so we enforce that each link relation is an array, even if it would only ever have one link.

Thanks for adding the tests @johnwatkins0! Instead of creating a new WP_REST_Server can we use rest_get_server() here?

[johnwatkins0]

Use rest_get_server instead of new WP_REST_Server

[johnwatkins0]

Thanks, @TimothyBlynJacobs. Updated in 49147.6.diff.

[TimothyBlynJacobs]

Uploaded a refreshed patch to use rest_url to build the link we compare against and some minor consistency changes.

[TimothyBlynJacobs]

Closed by r47326.