Custom fields and Featured Image from Relationship Field

[amydws]

My custom post type has associated posts from a different post type via ACF Relationship Field. I see that the associated post's title and content is automatically shown under "acf": {} but that post's custom fields and featured image are not shown. Is there a way to get those fields as well?

[amydws]

I figured out from other Issues how to get the custom fields from the relationship objects #223

I'm still trying to figure out how to get the featured image from the relationship object.

[amydws]

I added the thumbnail image URL to the Rest API for my custom post type, then used this thread to make the output match in the relationship post object output.
#153

This is solved.

[posadallano]

Thanks @amydws very helpful.

[fredericpfisterer]

Hello,

I'm trying to retrieve ACF data and featured image from post object from a relationship field. The acf-to-rest-api-recursive plugin solves the first part but how can I add the featured image information ? I tried the links provided by @amydws but without success.

Thanks in advance :)

[roryheaney]

@fredericpfisterer did you get this figured out?

[fredericpfisterer]

Not really :(

[SimonIMG]

I managed to do this with the help of this post by Rory Heaney.

First, I created a new relationship field called Related Posts, ensuring I ticked the Featured Image checkbox in Elements and set the Return Format to Post Object.

Next, I installed the ACF to REST API recursive plugin so I was able to query the ACF fields of posts in the relationship field (not required to get the Featured Image, but I thought it was worth mentioning).

Then I added this to my functions.php

/**
 * Add ability to query the featured image on posts added by the ACF relationship field.
 */
add_filter(
	'acf/rest_api/post/get_fields',
	function ( $item, $request ) {

		if ( isset( $item['acf']['related_posts'] ) ) {
			foreach ( $item['acf']['related_posts'] as $key => $relation ) {
				$relation_id = $relation->ID;

				$featured = wp_get_attachment_image_src( get_post_thumbnail_id( $relation->ID ), 'full' );

				if ( $featured ) $item['acf']['related_posts'][ $key ]->featured_image = $featured[0];
			}
		}

		return $item;
	},
	10,
	2
);

[SimonIMG]

^^ Following on from what I added above.

No need for (ACF to REST API recursive plugin)[https://github.com/airesvsg/acf-to-rest-api-recursive.git] at all. I've disabled it (it was causing Gatsby issues).

I also needed to get the related image of custom posts. I found both (Rory Heaney)[https://fancysquares.blog/posts/wordpress-rest-api-add-featured-image-to-acf-relationship-post-object] and (another support reply)[https://wordpress.org/support/topic/show-the-field-label-values-in-acf-rest-api/#post-9602402] said to use add_filter( 'acf/rest_api/{type}/get_fields', (using the wiildcard {type} instead of the post type slug post).

But my gatsby develop didn't like this. So we need to use an add_filter hook for each custom post type we want to query the featured images for.

/**
 * Add ability to query the featured image on posts added by the ACF relationship field.
 *
 * Reference: https://github.com/airesvsg/acf-to-rest-api/issues/251
 */
function get_featured_image_of_related( $item, $request ) {
	if ( isset( $item['acf']['related_posts'] ) ) {
		foreach ( $item['acf']['related_posts'] as $key => $relation ) {
			$relation_id = $relation->ID;

			$featured = wp_get_attachment_image_src( get_post_thumbnail_id( $relation->ID ), 'full' );

			if ( $featured ) {
				$item['acf']['related_posts'][ $key ]->featured_media = $featured[0];
			}
		}
	}

	return $item;
}

/**
 * Add a custom hook for each post type where we want to query the related post featured image
 */
add_filter(
	'acf/rest_api/post/get_fields',
	get_featured_image_of_related,
	10,
	2
);

add_filter(
	'acf/rest_api/case_study/get_fields',
	get_featured_image_of_related,
	10,
	2
);

For more custom post types, simply add a new hook (ie. copy the add_filer block and update the path: 'acf/rest_api/[YOUR_POST_TYPE_SLUG]/get_fields',

[reslear]

or use deep for include Featured Image in Relationship Field

function set_featured_image(&$item, $key){
	if(isset($item->post_type) && isset($item->ID) ) {
		$id = $item->ID;
		$featured = wp_get_attachment_image_src( get_post_thumbnail_id($id), 'full' );
		$item->featured_media = $featured ? $featured[0] : null;
	}
}


function get_featured_image_of_related( $item, $request ) {
	if( !empty($item) ) {
		array_walk_recursive($item['acf'], 'set_featured_image');
		return $item;
	}
}

$featured_image_post_types = array('post', 'page');

foreach($featured_image_post_types as $item) {
	add_filter("acf/rest_api/{$item}/get_fields", get_featured_image_of_related, 10, 2);
}

[joehannouch]

Thanks for all the suggestions, i still didn't manage to make this work,

I have a custom post type with a relationship field that I'm not able to expose the featured image (of the relationship items) in rest

here's my code taken from the links you shared.

add_filter( 'acf/rest_api/{type}/get_fields', function ( $item, $request ) {
if ( isset( $item['acf']['relationship'] ) ) {
foreach( $item['acf']['relationship'] as $key => $relation ) {
$relation_id = $relation->ID;
$featured = wp_get_attachment_image_src( get_post_thumbnail_id( $relation->ID ), 'full' );
if ( $featured ) $item['acf']['relationship'][$key]->featured_image = $featured[0];
}
}
return $item;
}, 10, 2 );

The relationship object still looks like this:

"relationship": [
{
"ID": 312,
"post_author": "1",
"post_date": "2021-01-14 13:58:45",
"post_date_gmt": "2021-01-14 13:58:45",
"post_content": "",
"post_title": "Original Bowl",
"post_excerpt": "",
"post_status": "publish",
"comment_status": "open",
"ping_status": "closed",
"post_password": "",
"post_name": "acai-original-bowl-copy",
"to_ping": "",
"pinged": "",
"post_modified": "2021-01-14 13:58:49",
"post_modified_gmt": "2021-01-14 13:58:49",
"post_content_filtered": "",
"post_parent": 0,
"guid": "localhost/?post_type=product&p=312",
"menu_order": 0,
"post_type": "product",
"post_mime_type": "",
"comment_count": "0",
"filter": "raw"
},

I tried the above-proposed code too but I get warnings at get_featured_image_of_related

Thank you!

[niran00]

@joehannouch
Where you able to find a solution?
I am trying to do the exact same thing, but instead of a featured image in the relationship object, I need to call in acf google maps field.

[joehannouch]

@joehannouch
Where you able to find a solution?
I am trying to do the exact same thing, but instead of a featured image in the relationship object, I need to call in acf google maps field.

No, i ended up calling both apis and building manually the json in the frontend.

[yannickninot]

You can juste do this
<?php foreach ( $featured_posts as $post ) { setup_postdata($post); if ( !empty(get_the_post_thumbnail($post->ID)) ) { echo get_the_post_thumbnail($post->ID); } } ?>