Fix xml formatter.

src/Serilog.Ui.Web/wwwroot/js/main.js

@@ -45,7 +45,7 @@
         let message = $(this).find("span").text();
 
         if (dataType === "xml") {
-            message = formatXml(message);
+            message = formatXml(message, '  ');
             $(modalBody).removeClass('wrapped');
         } else if (dataType === "json") {
             const prop = JSON.parse(message);
@@ -58,4 +58,15 @@
         modalBody.find('pre').text(message);
         modal.modal("show");
     });
-})(jQuery);
+})(jQuery);
+
+function formatXml(xml, tab) { // tab = optional indent value, default is tab (\t)
+    var formatted = '', indent = '';
+    tab = tab || '\t';
+    xml.split(/>\s*</).forEach(function (node) {
+        if (node.match(/^\/\w/)) indent = indent.substring(tab.length); // decrease indent by one 'tab'
+        formatted += indent + '<' + node + '>\r\n';
+        if (node.match(/^<?\w[^>]*[^\/]$/)) indent += tab;              // increase indent
+    });
+    return formatted.substring(1, formatted.length - 3);
+}