GP Nested Forms: Limit Entries Based on Another Field's Numeric Value

gpnf-limit-entry-min-max-from-field.php

<?php

class GP_Nested_Forms_Dynamic_Entry_Min_Max {

	public function __construct( $args = array() ) {

		// set our default arguments, parse against the provided arguments, and store for use throughout the class
		$this->_args = wp_parse_args( $args, array(
			'parent_form_id'       => false,
			'nested_form_field_id' => false,
			'default_max'          => 0, // Max to fallback to if the dependent field isn't populated
			'default_min'          => 0, // Min to fallback to if the dependent field isn't populated
			'max_field_id'         => null,
			'min_field_id'         => null, // (Optional)
		) );

		// do version check in the init to make sure if GF is going to be loaded, it is already loaded
		add_action( 'init', array( $this, 'init' ) );

	}

	public function init() {

		// make sure we're running the required minimum version of Gravity Forms
		if ( ! property_exists( 'GFCommon', 'version' ) || ! version_compare( GFCommon::$version, '1.8', '>=' ) ) {
			return;
		}

		// time for hooks
		add_filter( 'gform_pre_render', array( $this, 'load_form_script' ), 10, 2 );
		add_filter( 'gform_register_init_scripts', array( $this, 'add_init_script' ), 5, 2 );
		add_action( 'gform_validation', array( $this, 'validate' ) );

	}

	public function load_form_script( $form, $is_ajax_enabled ) {

		if ( $this->is_applicable_form( $form ) && ! has_action( 'wp_footer', array( $this, 'output_script' ) ) ) {
			add_action( 'wp_footer', array( $this, 'output_script' ) );
			add_action( 'gform_preview_footer', array( $this, 'output_script' ) );
		}

		return $form;
	}

	public function validate( $validation_result ) {

		if ( $validation_result['form']['id'] != $this->_args['parent_form_id'] ) {
			return $validation_result;
		}

		if ( ! $this->_args['max_field_id'] && ! $this->_args['min_field_id'] ) {
			return $validation_result;
		}

		$form                    = $validation_result['form'];
		$nested_form_field_id    = $this->_args['nested_form_field_id'];
		$nested_form_field_value = rgpost( "input_{$nested_form_field_id}" );
		$nested_form_field       = GFAPI::get_field( $form, $nested_form_field_id );

		$entry_ids   = explode( ',', $nested_form_field_value );
		$entry_count = empty( $nested_form_field_value ) ? 0 : count( $entry_ids );

		$raw_min = rgpost( "input_{$this->_args['min_field_id']}" );
		$raw_max = rgpost( "input_{$this->_args['max_field_id']}" );

		if ( empty( $raw_min ) ) {
			$raw_min = $this->_args['default_min'];
		}

		if ( empty( $raw_max ) ) {
			$raw_max = $this->_args['default_max'];
		}

		$min = apply_filters( 'gpnf_entry_limit_min', $raw_min, $entry_count, $entry_ids, null, $form );
		$max = apply_filters( 'gpnf_entry_limit_max', $raw_max, $entry_count, $entry_ids, null, $form );

		$has_validation_error = false;

		foreach ( $validation_result['form']['fields'] as &$field ) {

			if ( $field['failed_validation'] ) {
				$has_validation_error = true;
			}

			if ( $field['id'] !== $nested_form_field_id ) {
				continue;
			}

			if ( $min !== null && $min !== '' && $entry_count < $min ) {
				$field['failed_validation']  = true;
				$field['validation_message'] = sprintf( __( 'Please enter a minimum of %d %s', 'gp-nested-forms' ), $min, $min > 1 ? $nested_form_field->get_items_label() : $nested_form_field->get_item_label() );

				$has_validation_error = true;
			}

			if ( $max !== null && $max !== '' && $entry_count > $max ) {
				$field['failed_validation']  = true;
				$field['validation_message'] = sprintf( __( 'Please enter a maximum of %d %s', 'gp-nested-forms' ), $max, $max > 1 ? $nested_form_field->get_items_label() : $nested_form_field->get_item_label() );

				$has_validation_error = true;
			}

		}

		$validation_result['is_valid'] = ! $has_validation_error;

		return $validation_result;

	}

	public function output_script() {
		?>

        <script type="text/javascript">

            (function ($) {

                window.GPNFDynamicEntryMax = function (args) {

                    var self = this;

                    // copy all args to current object: (list expected props)
                    for (prop in args) {
                        if (args.hasOwnProperty(prop))
                            self[prop] = args[prop];
                    }

                    self.init = function () {

                        var $maxField = $('#input_' + self.parentFormId + '_' + self.maxFieldId);

                        gform.addFilter('gpnf_entry_limit_max', function (max, currentFormId, currentFieldId) {
                            if (self.parentFormId != currentFormId || self.nestedFormFieldId != currentFieldId) {
                                return max;
                            }

                            var value = parseInt($maxField.val());

                            return value ? value : self.defaultMax;
                        });

                        $maxField.on('change', function () {
                            // Force Knockout to recalculate the max when the number has changed
                            window['GPNestedForms_' + self.parentFormId + '_' + self.nestedFormFieldId].viewModel.entries.valueHasMutated();
                        });

                    };

                    self.init();

                }

            })(jQuery);

        </script>

		<?php
	}

	public function add_init_script( $form ) {

		if ( ! $this->is_applicable_form( $form ) ) {
			return;
		}

		$args = array(
			'parentFormId'      => $this->_args['parent_form_id'],
			'nestedFormFieldId' => $this->_args['nested_form_field_id'],
			'defaultMax'        => $this->_args['default_max'],
			'maxFieldId'        => $this->_args['max_field_id'],
		);

		$script = 'new GPNFDynamicEntryMax( ' . json_encode( $args ) . ' );';
		$slug   = implode( '_', array(
			'gpnf_dynamic_entry_max_template',
			$this->_args['parent_form_id'],
			$this->_args['nested_form_field_id']
		) );

		GFFormDisplay::add_init_script( $this->_args['parent_form_id'], $slug, GFFormDisplay::ON_PAGE_RENDER, $script );

	}

	public function is_applicable_form( $form ) {

		$form_id = isset( $form['id'] ) ? $form['id'] : $form;

		return empty( $this->_args['form_id'] ) || $form_id == $this->_args['form_id'];
	}

}

new GP_Nested_Forms_Dynamic_Entry_Min_Max( array(
	'parent_form_id'       => 4,
	'nested_form_field_id' => 3,
	'max_field_id'         => 1,
	'min_field_id'         => 2, // (Optional)
) );

Hi @jkyllonen,

Please send us an e-mail via https://gravitywiz.com/support and we'd be happy to help out with the snippet. 😃