Permit rest_do_request() to be used in non-REST API contexts

[danielbachhuber]

rest_do_request() currently requires $wp_rest_server to be properly instantiated:

function rest_do_request( $request ) {
    global $wp_rest_server;
    $request = rest_ensure_request( $request );
    return $wp_rest_server->dispatch( $request );
}

We should improve it such that it initializes $wp_rest_server if it isn't already loaded, such that you could use rest_do_request() in a non-REST API context.

@joehoyle wrote an ​equivalent function we can crib from.

[westonruter]

+1

In my looong career with the REST API (*wink*), I've already had to write an equivalent to this rest_internal_request() function a couple times to ensure the $wp_rest_server is constructed for internal requests.

[TimothyBlynJacobs]

Would it be worth it to have a rest_get_server() function?

[rmccue]

Replying to TimothyBlynJacobs:

Would it be worth it to have a rest_get_server() function?

I think this is a good idea.

[swissspidy]

35329.diff​ adds the rest_internal_request() function created by joehoyle and a new rest_get_server() function to get (and maybe set) the server instance. Not sure if the former is needed, but rest_get_server() feels like a great idea. Just think of all the places where global $wp_rest_server wouldn't be needed anymore.

[danielbachhuber]

I think we should add the logic of rest_internal_request() to rest_do_request(), given rest_do_request() already exists in core.

[rmccue]

New patch added. I dropped rest_internal_request() (I don't think we need this given the other pieces) and replaced the rest_api_loaded() internals to avoid duplication of the API initialisation.

I don't think we need unit tests for this version (now that we don't have rest_internal_request())?

[rmccue]

Patch without rest_internal_request

[danielbachhuber]

Patch uses rest_get_server() when initializing REST server tests

[swissspidy]

Just that it's not forgotten, the version used in the @since docs for the hooks of course shouldn't change.

[danielbachhuber]

Use corrected @since tags

[rachelbaker]

@rmccue @joehoyle @swissspidy The latest patch here looks good to me, but I understand the use-case well enough to be comfortable committing it. Can you help get this in 4.5?

[rmccue]

Fixed in r36529.

[rmccue]

In 36531:

REST API: Fix tests from r36529.

See #35329.

[DrewAPicture]

In 36947:

Docs: Improve syntax in the DocBlock for rest_get_server(), introduced in [36529].

See #35329. See #35986.