Ninja Forms File Uploads - temporary fix to ensure file uploads still work after the unique email error is triggered in a form submission

nf_fu_unique_email_error_fix.php

<?php

add_action( 'plugins_loaded', function () {
	/**
	 * Submission class extension so we can access the protected errors property.
	 *
	 * Class NF_FU_AJAX_Controllers_Submission
	 */
	class NF_FU_AJAX_Controllers_Submission extends NF_AJAX_Controllers_Submission {

		public function get_errors() {
			return $this->_errors;
		}
	}

	/**
	 * Convert a Submission object to our class.
	 *
	 * @param NF_AJAX_Controllers_Submission $submission
	 *
	 * @return NF_FU_AJAX_Controllers_Submission
	 */
	function nf_fu_convert_submission_object( $submission ) {
		$class = 'NF_FU_AJAX_Controllers_Submission';

		return unserialize( preg_replace( '/^O:\d+:"[^"]++"/', 'O:' . strlen( $class ) . ':"' . $class . '"', serialize( $submission ) ) );
	}

	add_action( 'ninja_forms_before_response', 'nf_fu_unique_email_error_fix' );

	function nf_fu_unique_email_error_fix( $data ) {
		$submission = Ninja_Forms()->controllers['submission'];

		if ( ! $submission ) {
			return;
		}

		$fu_submission = nf_fu_convert_submission_object( $submission );

		if ( ! $fu_submission || empty( $fu_submission->get_errors() ) ) {
			return;
		}

		$errors = $fu_submission->get_errors();

		if ( ! isset( $errors['fields'] ) || empty( $errors['fields'] ) ) {
			return;
		}

		$unique_field_error = false;

		foreach ( $errors['fields'] as $field_id => $field_error ) {
			if ( $field_error['slug'] === 'unique_field' ) {
				$unique_field_error = true;
				break;
			}
		}

		if ( ! $unique_field_error ) {
			return;
		}

		$tmp_dir = NF_File_Uploads()->controllers->uploads->get_temp_dir();

		foreach ( $data['fields'] as $field_id => $field ) {
			if ( $field['type'] !== NF_FU_File_Uploads::TYPE ) {
				continue;
			}

			foreach ( $field['files'] as $file ) {
				$tmp_file = $tmp_dir . '/' . $file['tmp_name'];
				copy( $file['data']['file_path'], $tmp_file );
			}
		}

		return;
	}
} );