src/properties/class-papi-property-link.php
public function update_value( $values, $slug, $post_id ) {
		if ( is_object( $values ) ) {
			$values = (array) $values;
		}

		if ( ! isset( $values['url'] ) ) {
			$values = $this->link_fields;

			foreach ( $values as $index => $key ) {
				$values[sprintf( '%s_%s', $slug, $key )] = '';
				unset( $values[$index] );
			}

			// Delete the required field.
			$values[$slug] = '';

			return $values;
		}

		// If a url exists we can continue making the meta fields
		// that should be saved.
		$values = $this->prepare_link_array( $values, $slug );

		foreach ( $values as $key => $val ) {
			$values[sprintf( '%s_%s', $slug, $key )] = $val;
			unset( $values[$key] );
		}

		// Required field so Papi can load a value from the
		// original property slug.
		$values[$slug] = 1;

		return $values;
	}
public function update_value( $values, $slug, $post_id ) {
		if ( is_object( $values ) ) {
			$values = (array) $values;
		}

		if ( ! isset( $values['url'] ) ) {
			$values = $this->link_fields;

			foreach ( $values as $index => $key ) {
				$values[sprintf( '%s_%s', $slug, $key )] = '';
				unset( $values[$index] );
			}

			// Delete the required field.
			$values[$slug] = '';

			return $values;
		}

		// If a url exists we can continue making the meta fields
		// that should be saved.
		$values = $this->prepare_link_array( $values, $slug );

		foreach ( $values as $key => $val ) {
			$values[sprintf( '%s_%s', $slug, $key )] = $val;
			unset( $values[$key] );
		}

		// Required field so Papi can load a value from the
		// original property slug.
		$values[$slug] = 1;

		return $values;
	}
Prepare value for the database.

@param  mixed  $values
@param  string $slug
@param  int    $post_id

@return array