Use List Field as Choices for Gravity Forms

<?php
/**
 * Gravity Wiz // Gravity Forms // Use List Field as Choices for Gravity Forms
 * https://gravitywiz.com/use-list-field-choices-gravity-forms/
 */

# Basic Usage
new GW_List_Field_As_Choices( array(
	'form_id'          => 1,
	'list_field_id'    => 2,
	'choice_field_ids' => 3,
) );

# Enable Sorting of Choices Alphanumerically
new GW_List_Field_As_Choices( array(
	'form_id'          => 1,
	'list_field_id'    => 2,
	'choice_field_ids' => 3,
	'sort'             => true,
) );

# Populating Multiple Choice Fields
new GW_List_Field_As_Choices( array(
	'form_id'          => 384,
	'list_field_id'    => 3,
	'choice_field_ids' => array( 6, 7 ),
) );

# Customizing the Choice Label and Value
new GW_List_Field_As_Choices( array(
	'form_id'          => 384,
	'list_field_id'    => 2,
	'choice_field_ids' => array( 4, 5 ),
	'label_template'   => '{Name} <span style="color:#999;font-style:italic;">({Age})</span>',
	'value_template'   => '{Name}',
) );

# Filter Usage

## Customize List field values to be populated as choices based on Gravity Flow User Input step.
add_filter( 'gwlfac_list_field_values', function( $values, $form, $args ) {
	if ( is_array( $values ) ) {
		return $values;
	}

	// Confirm we are within a Gravity Flow Inbox.
	if ( rgget( 'lid' ) && rgget( 'page' ) == 'gravityflow-inbox' ) {
		$entry = GFAPI::get_entry( (int) rgget( 'lid' ) );
		// Verify the entry list field has previously stored values to use.
		if ( $entry ) {
			$values = unserialize( $entry[ $args['list_field_id'] ] );
			if ( ! is_array( $values ) ) {
				return false;
			} else {
				return $values;
			}
		}
	}
	return false;
}, 10, 3 );