gw-query-param-merge-tag.php: Added supported for targeting complex query params like filters[1]['foo'].

Author: spivurno

gravity-forms/gw-query-param-merge-tag.php

@@ -13,7 +13,7 @@
  * Description: Adds {query_param:PARAM} merge tags for pulling values from query/GET params.
  * Author: Gravity Wiz
  * Version: 0.1
- * Author URI: http://gravitywiz.com
+ * Author URI: https://gravitywiz.com
  */
 add_filter( 'gform_replace_merge_tags', function( $text, $form, $entry, $url_encode, $esc_html, $nl2br, $format ) {
 	preg_match_all( '/\{query_param:(.*?)\}/', $text, $dyn_pop_matches, PREG_SET_ORDER );
@@ -23,11 +23,52 @@
 			$full_tag = $match[0];
 			$modifier = $match[1];
 
-			$value = sanitize_text_field( esc_sql( rgget( $modifier ) ) );
+			$value = sanitize_text_field( esc_sql( gw_get_get_query_param( $modifier ) ) );
 
 			$text = str_replace( $full_tag, $url_encode ? urlencode( $value ) : $value, $text );
 		}
 	}
 
 	return $text;
 }, 10, 7 );
+
+if ( ! function_exists( 'gw_get_query_param' ) ) :
+	/**
+	 * Get a query parameter value from $_GET when the key may use
+	 * array syntax like filters[53][foo], possibly URL-encoded.
+	 *
+	 * Examples:
+	 *   gw_get_get_query_param( 'filters[53]' );
+	 *   gw_get_get_query_param( 'filters%5B53%5D' );
+	 *   gw_get_get_query_param( 'filters[53][foo]' );
+	 */
+	function gw_get_get_query_param( $key ) {
+
+		// Normalize the incoming key using WP helpers.
+		$key = wp_unslash( $key );      // In case it came from a request.
+		$key = urldecode( $key );       // Decode URL-encoded names like filters%5B53%5D.
+		$key = trim( $key, "\"'" );     // Strip surrounding quotes.
+
+		// Work with an unslashed copy of $_GET.
+		$get = wp_unslash( $_GET );
+
+		// No array syntax – return directly.
+		if ( strpos( $key, '[' ) === false ) {
+			return isset( $get[ $key ] ) ? $get[ $key ] : null;
+		}
+
+		// Convert "filters[53][foo]" → [ 'filters', '53', 'foo' ].
+		$parts = preg_split( '/\[|\]/', $key, -1, PREG_SPLIT_NO_EMPTY );
+
+		$value = $get;
+
+		foreach ( $parts as $part ) {
+			if ( ! is_array( $value ) || ! array_key_exists( $part, $value ) ) {
+				return null;
+			}
+			$value = $value[ $part ];
+		}
+
+		return $value;
+	}
+endif;