WordPress REST Api get posts by ID

Question

Hi I'm building up a WordPress rest API's custom endpoint on my project. I'm using the following code to get the single response from the website.

function get_single_post( $request ) {
    
    $response = array();
    $args = [
        'id' => $request['id'],
        'post_type' => 'payment',
    ];
    $post = get_posts($args);

    $metas = get_post_meta($request['id'],'');
    $post_id = $post->ID;

    $response[$post_id]['response'] = $post[0];
    $response[$post_id]['metas'] = $metas;

    return $response;
}

add_action('rest_api_init', function(){
    register_rest_route('booking/v1', 'posts',[
        'methods'=> 'GET',
        'callback' => 'booking_posts',
    ]);
    
    register_rest_route('booking/v1','/posts/(?P<id>\d+)',[
        'methods' => 'GET',
        // Register the callback for the endpoint.
        'callback' => 'get_single_post',
    ]);
});

I'm not getting the post with the posts/ in my response. Kindly advise what I'm doing wrong here?

Here's my response:

{
"": {
"response": {
"ID": 12042,
"post_author": "10",
"post_date": "2020-06-12 15:15:42",
"post_date_gmt": "2020-06-12 14:15:42",
"post_content": "",
"post_title": "xxxxxxxxxxxxxxx",
"post_excerpt": "",
"post_status": "publish",
"comment_status": "closed",
"ping_status": "closed",
"post_password": "",
"post_name": "xxxxxxxxxxx",
"to_ping": "",
"pinged": "",
"post_modified": "2020-06-12 15:15:42",
"post_modified_gmt": "2020-06-12 14:15:42",
"post_content_filtered": "",
"post_parent": 0,
"guid": "https://xxxxxxxx/payment/xxxxxxxxxx/",
"menu_order": 0,
"post_type": "payment",
"post_mime_type": "",
"comment_count": "0",
"filter": "raw"
},
"metas": {
"chauffeur_payment_status": [
"Unpaid"
],
"chauffeur_payment_num_passengers": [
"1"
],
"chauffeur_payment_num_bags": [
"0"
],
"chauffeur_payment_first_name": [
"xxxxxxx"
],
"chauffeur_payment_last_name": [
"xxxxxxxx"
],
"chauffeur_payment_email": [
"xxxxxxxxx"
],
"chauffeur_payment_phone_num": [
"xxxxxx"
],
"chauffeur_payment_flight_number": [
""
],
"chauffeur_payment_additional_info": [
""
],
"chauffeur_payment_pickup_address": [
"xxxxxxx"
],
"chauffeur_payment_dropoff_address": [
"xxxxxxxx"
],
"chauffeur_payment_pickup_date": [
"12/06/2020"
],
"chauffeur_payment_pickup_time": [
"12:00"
],
"chauffeur_payment_trip_distance": [
"3,907 km"
],
"chauffeur_payment_trip_time": [
"1 day 12 hours"
],
"chauffeur_payment_item_name": [
"Standard-size taxi"
],
"chauffeur_payment_trip_type": [
"one_way"
],
"chauffeur_payment_return_journey": [
"One Way"
],
"chauffeur_payment_num_hours": [
""
],
"chauffeur_payment_amount": [
"xxxx"
],
"chauffeur_payment_full_pickup_address": [
""
],
"chauffeur_payment_pickup_instructions": [
""
],
"chauffeur_payment_full_dropoff_address": [
""
],
"chauffeur_payment_dropoff_instructions": [
""
]
}
}
}

The id of response->ID should be same as posts/. It's not.

Answer 1

You're getting that mismatched values because you're using the wrong argument for the post ID in your $args array (i.e. the query args for WP_Query). And the correct argument is p (lowercase P) and not id:

$args = [
//  'id' => $request['id'], // wrong argument name - 'id'
    'p' => $request['id'],  // and the correct one is 'p'
    'post_type' => 'payment',
];

And in addition to that main issue, another one I noticed is the $post_id = $post->ID; whereby that $post is an array and not object. So did you mean to use $post_id = $post[0]->ID; ?

Also, why do you have to use get_posts()? Why not just use get_post() — $post = get_post( $request['id'] ); ? That way, the above $post_id = $post->ID; would be valid. So for example, this is how your code would look like when using get_post():

if ( ! $post = get_post( $request['id'] ) ) {
    return new WP_Error( 'your_error_code_here', 'Please define a valid post ID.' );
}

$metas = get_post_meta( $request['id'] );
$post_id = $post->ID;

$response[ $post_id ]['response'] = $post;

Answer 2

Hope this helps someone, this uses ACF Custom Fields as well:

routes/site-route.php

<?php

class SiteRestRouter
{

  public function __construct()
  {
    $this->register_routes();
  }

  public function get_site($request)
  {
    $args = array(
      'p' => $request['id'],
      'post_type' => 'site',
    );

    if ( ! $post = get_post( $request['id'] ) ) {
      return new WP_Error( 'invalid_id', 'Please define a valid post ID.' );
    }

    $query = new WP_Query($args);

    if ($query -> have_posts()) {
      $query->the_post();
      $post = get_post(get_the_ID());
      $id = get_the_ID();
      $title = $post->post_title;
      $last_updated = get_field('last_updated');
      $deployment_location = get_field('location');
      $git_location = get_field('git_location');
      $database_location = get_field('database_location');
      $host = get_field('host');
      $protected_by_cloudflare = get_field('cloudflare');
      $maintenance = get_field('maintenance');
      $php_version = get_field('php_version');
      $wordpress_version = get_field('wordpress_version');
      $assigned_to = get_field('assigned_to');
      $notes = get_field('notes');
      $logs = get_field('logs');

      $response['id'] = $id;
      $response['title'] = $title;
      $response['last_updated'] = $last_updated;
      $response['deployment_location'] = $deployment_location;
      $response['git_location'] = $git_location;
      $response['database_location'] = $database_location;
      $response['host'] = $host;
      $response['protected_by_cloudflare'] = $protected_by_cloudflare;
      $response['maintenance'] = $maintenance;
      $response['php_version'] = $php_version;
      $response['wordpress_version'] = $wordpress_version;
      $response['assigned_to'] = $assigned_to->post_title;
      $response['notes'] = $notes;
      $response['logs'] = $logs;
    }

    wp_reset_postdata();

    return $response;
  }

  protected function register_routes()
    {
      add_action('rest_api_init', function () {
        $namespace = 'api/v1/';

        register_rest_route($namespace, '/sites/(?P<id>\d+)', array(
          'methods' => 'GET',
          'callback' => array( $this, 'get_site' ),
        ));
      });
    }
}

new SiteRestRouter();

Add this to functions.php

require_once 'routes/site-route.php';