[GH Usage] Updated analytics click link index

Author: mogah

src/NuGetGallery/Scripts/gallery/page-display-package.js

@@ -119,16 +119,13 @@ $(function () {
         });
 
         // Emit a Google Analytics event when the user clicks on a repo link in the GitHub Usage section.
-        $(".btn-gh-repo").on('click', function (e) {
-            let elem = e.delegateTarget.parentElement.parentElement;
-            let linkIndex = 0;
-            while ((elem = elem.previousSibling) != null) {
-                if (elem.nodeName === "DIV") {
-                    linkIndex++;
-                }
+        $(".btn-gh-repo").on('click', function (elem) {
+            if (!elem.delegateTarget.dataset.indexNumber) {
+                console.error("indexNumber property doesn't exist!");
+            } else {
+                let linkIndex = elem.delegateTarget.dataset.indexNumber;
+                ga('send', 'event', 'github-usage', 'link-click-' + linkIndex);
             }
-
-            ga('send', 'event', 'github-usage', 'link-click-' + linkIndex);
         });
     }
 });

src/NuGetGallery/Views/Packages/DisplayPackage.cshtml

@@ -535,16 +535,16 @@
                             @(Model.Id), including the following:
                         </p>
 
-                        @foreach (var dep in Model.GitHubDependenciesInformation.Repos)
+                        @foreach (var item in Model.GitHubDependenciesInformation.Repos.Select((elem, i) => new { Value = elem, Idx = i}))
                         {
                             <div class="row top-buffer">
                                 <div class="col-xs-12">
-                                    <a class="btn btn-gh-repo text-left" href="@dep.Url" target="_blank">
+                                    <a data-index-number="@item.Idx" class="btn btn-gh-repo text-left" href="@item.Value.Url" target="_blank">
                                         <span class="pull-left">
-                                            @(dep.Id)
+                                            @(item.Value.Id)
                                         </span>
                                         <span class="badge pull-right badge-gh-repo">
-                                            @(dep.Stars.ToKiloFormat()) <i class="ms-Icon ms-Icon--FavoriteStarFill star-gh-repo" aria-hidden="true"></i>
+                                            @(item.Value.Stars.ToKiloFormat()) <i class="ms-Icon ms-Icon--FavoriteStarFill star-gh-repo" aria-hidden="true"></i>
                                         </span>
                                     </a>
                                 </div>