GravityForms Unique ID - Generates a alphanumeric, numeric, or sequential "Unique ID" for the entry when submitted

gravityforms-unique-id-sequence.php

<?php

/*
 - Add this to your functions.php
 - Add a form input normal
 - give it a gf-sequence class
 
*/

$gfex_gsf = false;

add_filter( 'gform_pre_render', 'gfex_sequence_field' );
function gfex_sequence_field( $form = null ) {
	global $gfex_gsf;
	foreach ( $form[ 'fields' ] as &$field ) {
		if ( strpos( $field->cssClass, 'gf-sequence' ) !== false ) {
			$field->defaultValue = gfex_sequence_next( $field->defaultValue, $field);
			$gfex_gsf = true;
			continue;
			$field->allowsPrepopulate = true;
			//if ( !empty( $field->inputName ) ) add_filter( 'gform_field_value_' . $field->inputName, 'gfex_sequence_next', 50, 3 );
			//else if ( !isset( $gfex_gsf ) || !$gfex_gsf ) {
			//	add_filter( 'gform_field_value', 'gfex_sequence_next', 50, 2 );
			//	$gfex_gsf = true;
			//}
		}
	}
	if ( $gfex_gsf ) {
		?>
		<script type="text/javascript">
			jQuery(document).ready(function(){
				jQuery( ".gf-sequence input" ).attr( "readonly","readonly" );
			});
		</script>
    <?php
	}
    return( $form );
}

add_filter( 'gform_save_field_value', 'gfex_sequence_save_field_value', 10, 3 );
function gfex_sequence_save_field_value( $value, $lead, $field ) {
	if ( strpos( $field->cssClass, 'gf-sequence' ) === false ) return( $value );
	return( gfex_sequence_next( $value, $field, false ) );
}

function gfex_sequence_next( $value, $field, $inc = 1 ) {
	global $gfex_gsf;
	if ( strpos( $field->cssClass, 'gf-sequence' ) === false ) return( $value );
	$form_id = $field->formId;
	$field_id =  $field->id;
	$prefix = apply_filters( 'gfex_sequence_prefix', '', $value, $field ); // date('Y') . '-';
	do {
		$count = RGFormsModel::get_form_counts( $form_id );
		$unique = $count[ 'total' ] + ( $inc ? $inc : 0 ); // count of the lead form entries incremented by one
		$unique = $prefix . str_pad( $unique, 3, '0', STR_PAD_LEFT ); // padding for number format 001,002...015 so 3 digit number format
	} while ( !gfex_sequence_check( $unique, $form_id, $field_id ) );
	return( $unique );
}

function gfex_sequence_check( $unique, $form_id, $field_id ) {
	global $wpdb;
	$table = $wpdb->prefix . 'rg_lead_detail';
	$result = $wpdb->get_var( "SELECT value FROM $table WHERE form_id = '$form_id' AND field_number = '$field_id' AND value = '$unique'" );
	return( empty( $result) );
}