Add option stateful, implement in changeState private function.

dist/README.md

@@ -231,6 +231,14 @@ default: 'bx-wrapper'
 options: string
 ```
 
+**stateful**
+Adds browser history state for any paging action, which views previous slides based on pager when users use browser 'back' or 'forward' buttons. Also appends the specified string to the address URL history. This is most useful for linking a specific slide, or when dynamic content is being loaded based on which slide is being viewed.
+
+```
+default: false
+options: string
+```
+
 ###Pager
 
 **pager**

dist/jquery.bxslider.js

@@ -53,6 +53,7 @@
     pagerSelector: null,
     buildPager: null,
     pagerCustom: null,
+    stateful: false,
 
     // CONTROLS
     controls: true,
@@ -340,6 +341,7 @@
       if (slider.settings.keyboardEnabled && !slider.settings.ticker) {
         $(document).keydown(keyPress);
       }
+      if (slider.settings.stateful){ changeState(0, true); }
     };
 
     /**
@@ -1316,6 +1318,47 @@
       }
     };
 
+    var changeState = function(slideNumber, firstLoad){
+      url = location.search;
+      theParam = slider.settings.stateful.toString(); // allows you to change the query string based on 
+      if(url){
+        searchIndex = url.indexOf('&' + theParam + '=');
+        // Decides if the param is listed in the url query, appends it if necessary.
+        if(searchIndex !== -1){
+          queryString = url.substring(0, searchIndex);
+          queryString += '&';
+        }else if(url.indexOf('?' + theParam + '=') > -1){
+          queryString = '?';
+        }else{
+          queryString = url  + '&';
+        }
+      }else{
+        queryString = '?';
+      }
+      if(firstLoad){ // on first loading, and boolean.
+        slideSetTo = unescape(window.location.search.replace(new RegExp("^(?:.*[&\\?]" + escape(theParam).replace(/[\.\+\*]/g, "\\$&") + "(?:\\=([^&]*))?)?.*$", "i"), "$1"));  
+
+        goState = true;
+        // set up event listener
+        window.onpopstate = function(e) {
+          // make sure pushstate doesn't trigger when using browser buttons
+          goState = false; 
+          el.goToSlide(parseInt(e.state));
+        };
+        if(slideSetTo){
+          goState = false;
+          window.history.replaceState(slideSetTo, slideSetTo, queryString + theParam + "=" + slideSetTo); // ensures state is set when someone comes in with query string.
+          el.goToSlide(slideSetTo);
+        }
+
+      }else {
+        if(goState){ // won't run if using back or forward button, otherwise it's a redundant call.
+          window.history.pushState(slideNumber, slideNumber, queryString +  theParam + "=" + slideNumber);
+        }
+        goState = true;
+      }
+    };
+
     /**
      * ===================================================================================
      * = PUBLIC FUNCTIONS
@@ -1439,6 +1482,9 @@
         }
       }
       if (slider.settings.ariaHidden) { applyAriaHiddenAttributes(slider.active.index * getMoveBy()); }
+
+      // if stateful is enabled
+      if (slider.settings.stateful){ changeState(slider.active.index, false); }
     };
 
     /**
@@ -1592,6 +1638,7 @@
       $(this).removeData('bxSlider');
     };
 
+
     /**
      * Reload the slider (revert all DOM changes, and re-initialize)
      */