Why can't I access the query params from WP_REST_Request?

Question

On my blog, I'm trying to create an endpoint in order to load more articles using ajax. However, the query string parameters don't seem to be passed down to my function. Here's my code, all of it is in the function.php file:

add_action( 'rest_api_init', function () {
  register_rest_route( 'blog', '/articles', array(
    'methods' => WP_REST_Server::READABLE,
    'callback' => 'load_more'
  ));
});

function load_more(WP_REST_Request $request) {
  var_dump($request->has_valid_params());
  var_dump($request->get_params());
  var_dump($request);
}

And here is what this returns when I call /wp-json/blog/articles/?lang=en&tag=test :

bool(true)

array(0) {}

object(WP_REST_Request)#2259 (8) {
  ["method":protected]=>
  string(3) "GET"
  ["params":protected]=>
  array(6) {
    ["URL"]=>
    array(0) {
    }
    ["GET"]=>
    array(0) {
    }
    ["POST"]=>
    array(0) {
    }
    ["FILES"]=>
    array(0) {
    }
    ["JSON"]=>
    NULL
    ["defaults"]=>
    array(0) {
    }
  }
  ["body":protected]=>
  string(0) ""
  ["route":protected]=>
  string(14) "/blog/articles"
  ["attributes":protected]=>
  array(6) {
    ["methods"]=>
    array(1) {
      ["GET"]=>
      bool(true)
    }
    ["accept_json"]=>
    bool(false)
    ["accept_raw"]=>
    bool(false)
    ["show_in_index"]=>
    bool(true)
    ["args"]=>
    array(0) {
    }
    ["callback"]=>
    string(9) "load_more"
  }
  ["parsed_json":protected]=>
  bool(true)
  ["parsed_body":protected]=>
  bool(false)
}

It's almost like the parameters were deleted from the request object before reaching my function.

Mainis

try using a different route, perhaps it is conflicting with existing slug somewhere? – Jeffry

Did you find a solution? I am facing the exact same issue. Happens only when the rest route is accessed in logged out state. – February

Could you refresh me a thing? This load_more(WP_REST_Request $request), what's the main purpose for WP_REST_Request? is it a function, a parameter, something expected or a callback? – Senna

Answer 1

You can access query parameters via WP_REST_Request::get_query_params():

$queryParams = $request->get_query_params();
$tag = $queryParams['tag'];

Alternatively you can use

$tag = $request->get_param('tag');

but that merges $_POST, $_GET and path parameters in that order

Dela

Answer 2

If you pass some value via POST REQUEST you can access them by using get_body_params() method

add_action( 'rest_api_init', function () {
    register_rest_route( "nh", "v2/slug", array(
      'methods' => 'POST',
      'callback' => 'my_awesome_func',
    ) );
  } );



function my_awesome_func( $request  ) {
    $queryParams = $request->get_body_params();
    return $queryParams;
}

Disjunctive

Answer 3

The object properties are protected therefore it is not possible to get them using the standard method, even if you want to access you will confront a Fatal Error.

I however tried to access values by first converting the object to array then loop through each item and get what is needed.

WP_REST_Request $request;
$request2 = (array)$request;
foreach($request2 as $req2) {
   if (is_array($req2)) {
     foreach($req2 as $req2_k => $req2_v) {
       if ($req2_k == 'cpt') {
          echo $req2_v;
       }
     }
   }
}

As you can see I wanted to obtain cpt value from attributes array index, you need to adjust the loop to your liking.

Wretch