gw-fuzzy-match.php: Added snippet for fuzzy comparison.

gravity-forms/gw-fuzzy-comparison.php

@@ -0,0 +1,188 @@
+<?php
+/**
+ * Gravity Wiz // Gravity Forms // Fuzzy Comparison for operator "is"
+ *
+ * This snippet adds fuzzy comparison for "is" operator with the GF conditional logic rules.
+ */
+class GW_Fuzzy_Match {
+
+	private $_args;
+
+	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(
+			'form_id'   => false,
+			'field_id'  => false,
+			'threshold' => 1,
+		) );
+
+		// 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() {
+		// Add hooks for PHP filtering
+		add_filter( 'gform_is_value_match', array( $this, 'apply_fuzzy_match' ), 10, 6 );
+
+		// Add hooks for JS script
+		add_filter( 'gform_pre_render', array( $this, 'load_form_script' ), 10, 2 );
+		add_action( 'gform_register_init_scripts', array( $this, 'add_init_script' ), 10, 2 );
+	}
+
+	public function apply_fuzzy_match( $is_match, $field_value, $target_value, $operation, $source_field, $rule ) {
+		if ( $rule['operator'] !== 'is' ) {
+			return $is_match;
+		}
+		return $this->fuzzy_match( $field_value, trim( $target_value ) );
+	}
+
+	public function fuzzy_match( $input, $target ) {
+		$normalized_input  = $this->normalize_string( $input );
+		$normalized_target = $this->normalize_string( $target );
+		$distance          = levenshtein( $normalized_input, $normalized_target );
+		return $distance <= $this->_args['threshold'];
+	}
+
+	public function normalize_string( $str ) {
+		$str = iconv( 'UTF-8', 'ASCII//TRANSLIT', $str );
+		return strtolower( preg_replace( '/[^a-zA-Z0-9]/', '', $str ) );
+	}
+
+	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 output_script() {
+		?>
+		<script type="text/javascript">
+			( function( $ ) {
+
+				window.GW_Fuzzy_Match = function( args ) {
+					var self = this;
+
+					// Copy all args to current object: (list expected props)
+					for( var prop in args ) {
+						if( args.hasOwnProperty( prop ) ) {
+							self[ prop ] = args[ prop ];
+						}
+					}
+
+					self.isApplicableField = function(fieldId) {
+						if ( typeof fieldId !== 'number' ) {
+							fieldId = parseInt( fieldId );
+						}
+
+						if ( ! self.fieldId ) {
+							return true;
+						}
+
+						if ( typeof self.fieldId !== 'object' ) {
+							self.fieldId = [ self.fieldId ];
+						}
+
+						// Ensure fieldIds are all numbers
+						self.fieldId = self.fieldId.map( function( fieldId ) {
+							if ( typeof fieldId === 'string' ) {
+								fieldId = parseInt( fieldId );
+							}
+							return fieldId;
+						} );
+
+						return self.fieldId.indexOf( fieldId ) !== -1;
+					};
+
+					self.init = function() {
+						gform.addFilter('gform_is_value_match', function (isMatch, formId, rule) {
+							if ( rule.operator !== 'is' ) {
+								return isMatch;
+							}
+							var source = jQuery( '#input_' + formId + '_' + rule.fieldId );
+							if ( source ) {
+								return self.fuzzyMatch( source.val(), rule.value );
+							}
+							return isMatch;
+						});
+					};
+
+					self.normalizeString = function( str ) {
+						return str.normalize("NFD").replace( /[\u0300-\u036f]/g, "" ).toLowerCase();
+					};
+
+					self.levenshtein = function( a, b ) {
+						const an = a.length;
+						const bn = b.length;
+						if (an === 0) return bn;
+						if (bn === 0) return an;
+						const matrix = [];
+						for (let i = 0; i <= bn; i++) {
+							matrix[i] = [i];
+						}
+						for (let j = 0; j <= an; j++) {
+							matrix[0][j] = j;
+						}
+						for (let i = 1; i <= bn; i++) {
+							for (let j = 1; j <= an; j++) {
+								if (b.charAt(i - 1) === a.charAt(j - 1)) {
+									matrix[i][j] = matrix[i - 1][j - 1];
+								} else {
+									matrix[i][j] = Math.min(
+										matrix[i - 1][j - 1] + 1,
+										Math.min(
+											matrix[i][j - 1] + 1,
+											matrix[i - 1][j] + 1
+										)
+									);
+								}
+							}
+						}
+						return matrix[bn][an];
+					};
+
+					self.fuzzyMatch = function( input, target ) {
+						const normalizedInput  = self.normalizeString( input );
+						const normalizedTarget = self.normalizeString( target );
+						const distance         = self.levenshtein( normalizedInput, normalizedTarget );
+						return distance <= self.threshold;
+					};
+
+					self.init();
+				};
+
+			} )( jQuery );
+		</script>
+		<?php
+	}
+
+	public function add_init_script( $form ) {
+		if ( ! $this->is_applicable_form( $form ) ) {
+			return;
+		}
+
+		$args = array(
+			'formId'    => $this->_args['form_id'],
+			'fieldId'   => $this->_args['field_id'],
+			'threshold' => $this->_args['threshold'],
+		);
+
+		$script = 'new GW_Fuzzy_Match( ' . json_encode( $args ) . ' );';
+		$slug   = implode( '_', array( strtolower( __CLASS__ ), $this->_args['form_id'], $this->_args['field_id'] ) );
+
+		GFFormDisplay::add_init_script( $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'] ) || (int) $form_id === (int) $this->_args['form_id'];
+	}
+}
+
+# Configuration
+new GW_Fuzzy_Match( array(
+	'form_id'   => 1,  // Replace with your form ID.
+	'field_id'  => 2,  // Replace with your field ID for which conditional logic needs to be fuzzy.
+	'threshold' => 1,  // Define your threshold - It is the maximum number of allowed differences between two strings for them to be considered similar.
+) );