PHP API

The primary API uses the ncr_ prefix. Legacy wp_* wrappers remain for backward compatibility.

Quick reference

Function	Purpose
ncr_add_relation( $from_id, $from_type, $to_id, $to_type, $relation_type )	Create one relationship
ncr_get_related( $from_id, $from_type, $relation_type, $args = [] )	Get related IDs or objects
ncr_remove_relation( $from_id, $from_type, $to_id, $to_type, $relation_type )	Remove one or all (use $to_id = null for all)
ncr_register_relation_type( $args )	Register a custom relation type
ncr_get_registered_relation_types()	List registered types

Object types: 'post', 'user', 'term'. See Relationships for copy-paste examples.

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ncr_add_relation()

Creates a relationship between two objects.

ncr_add_relation( $from_id, $from_type, $to_id, $to_type, $relation_type );

Parameter	Type	Description
$from_id	int	Source object ID
$from_type	string	'post', 'user', or 'term'
$to_id	int	Target object ID
$to_type	string	'post', 'user', or 'term'
$relation_type	string	Registered relation type slug

Returns: int relation ID on success, WP_Error on failure.

Example:

// Link post 123 to post 456 as "related_to"
$relation_id = ncr_add_relation( 123, 'post', 456, 'post', 'related_to' );
if ( is_wp_error( $relation_id ) ) {
	// Handle error
}

ncr_get_related()

Retrieves related objects.

ncr_get_related( $from_id, $from_type, $relation_type, $args = [] );

Parameter	Type	Description
$from_id	int	Source object ID
$from_type	string	'post', 'user', or 'term'
$relation_type	string	Relation type slug
$args	array	limit, orderby, order, direction

Returns: Array of related IDs or objects, or WP_Error.

Example:

$related = ncr_get_related( get_the_ID(), 'post', 'related_to', [ 'limit' => 5, 'orderby' => 'created', 'order' => 'DESC' ] );
foreach ( (array) $related as $post_id ) {
	echo get_the_title( $post_id );
}

ncr_remove_relation()

Removes one or more relationships.

ncr_remove_relation( $from_id, $from_type, $to_id, $to_type, $relation_type );

Use $to_id = null to remove all relations of that type from $from_id.

Returns: true on success, WP_Error on failure.

Example:

// Remove one relation
ncr_remove_relation( 123, 'post', 456, 'post', 'related_to' );

// Remove all "related_to" from post 123
ncr_remove_relation( 123, 'post', null, 'post', 'related_to' );

Legacy wrappers

• wp_add_relation( $from_id, $to_id, $type, $direction, $to_type )
• wp_get_related( $post_id, $type, $args, $to_type )
• wp_remove_relation( $from_id, $to_id, $type, $to_type )
• wp_get_related_users(), wp_get_related_terms(), wp_get_related_products() (WooCommerce)

Prefer ncr_* for new code.

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See also

• Relationships — Create, query, remove from code with examples
• Fluent API — Chainable naticore() wrapper
• Shortcodes — [naticore_related_posts], [naticore_related_users], [naticore_related_terms]
• WP_Query — Query by relationship in the loop
• Hooks & Filters — ncr_relation_added, naticore_relation_is_allowed