Docs module add alternative links for search engines

resolved https://github.com/abpframework/abp/issues/2316

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml

@@ -262,10 +262,13 @@
                                 }
                                 @Html.Raw(Model.Document.Content)
                             </article>
+
+                            <div id="crawler_link" style="display:none;">
+
+                            </div>
                         </div>
                     </div>
                 </div>
-
             </div>
 
             <div class="col-md-2 docs-page-index position-relative bg-light">
@@ -301,4 +304,3 @@
     </div>
 </div>
 
- 

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/index.js

@@ -183,6 +183,108 @@
             setQueryString();
         };
 
+        var initCrawlerLinks = function () {
+
+            var isCrawler = function () {
+                var crawlers = [
+                    'Google',
+                    'Googlebot',
+                    'YandexBot',
+                    'msnbot',
+                    'Rambler',
+                    'Yahoo', 
+                    'AbachoBOT', 
+                    'accoona', 
+                    'AcoiRobot',
+                    'ASPSeek',
+                    'CrocCrawler', 
+                    'Dumbot',
+                    'FAST-WebCrawler', 
+                    'GeonaBot', 
+                    'Gigabot',
+                    'Lycos', 
+                    'MSRBOT', 
+                    'Scooter',
+                    'AltaVista',
+                    'IDBot', 
+                    'eStyle', 
+                    'Scrubby', 
+                    'Slurp', 
+                    'DuckDuckBot', 
+                    'Baiduspider', 
+                    'VoilaBot', 
+                    'ExaLead', 
+                    'Search Dog', 
+                    'MSN Bot' , 
+                    'BingBot' 
+                ];
+
+                var agent = navigator.userAgent;
+
+                for (var i = 0; i < crawlers.length; i++) {
+
+                    if (agent.indexOf(crawlers[i]) >= 0) {
+                        return true;
+                    }
+                }
+
+                return false;
+            };
+
+            if (!isCrawler()) {
+                return;
+            }
+
+            var comboboxes = $(".doc-section-combobox");
+
+            if (comboboxes.length <= 0) {
+                return;
+            }
+
+            $("#crawler_link").show();
+
+            var html = '';
+
+            var currentUrl = window.location.href.toString();
+
+            if (currentUrl.indexOf("?") > 0) {
+                currentUrl = currentUrl.substring(0, currentUrl.indexOf("?"));
+            }
+
+            var getQueryStringsFromComboboxes = function (x) {
+                if (x >= comboboxes.length) {
+                    return [];
+                }
+
+                var key = $(comboboxes[x]).data("key");
+
+                var queryStrings = getQueryStringsFromComboboxes(x + 1);
+                var returnList = [];
+
+                $(comboboxes[x]).find("option").each(function () {
+
+                    if (queryStrings.length <= 0) {
+                        returnList.push(key + "=" + $(this).val());
+                        
+                    }
+                    else {
+                        for (var k = 0; k < queryStrings.length; k++) {
+                            returnList.push(key + "=" + $(this).val() + "&" + queryStrings[k]);
+                        }
+                    }
+                });
+
+                return returnList;
+            };
+
+            var queryStrings = getQueryStringsFromComboboxes(0);
+
+            for (var i = 0; i < queryStrings.length; i++) {
+                html += "<a href=\"" + currentUrl + "?" + queryStrings[i] +"\">" + queryStrings[i]+"</a> "
+            }
+
+            $("#crawler_link").html(html);
+        };
 
         initNavigationFilter("sidebar-scroll");
 
@@ -192,6 +294,8 @@
 
         initSections();
 
+        initCrawlerLinks();
+
     });
 
 })(jQuery);