@@ -65,4 +65,37 @@ serialize: function(data){return data;},
         config: xhrcfg
       });
   };
+  
+  Doc.patch = function(id, updatedTags){
+    console.log(updatedTags);
+    return Doc.get(id).then(function(doc){
+      var tags = doc.tags;
+      console.log(tags);
+      var count = 0;
+      var ops = [];
+      tags.forEach(function(tag){
+        if (updatedTags[count]){
+          if (updatedTags[count] != tag){
+            // update tag
+            ops.push({"op": "replace", "path": "/tags/"+count, "value": updatedTags[count]});
+          }
+        } else {
+          // delete tag
+          ops.push({"op": "remove", "path": "/tags/"+count});
+        }
+        count++;
+      });
+      if (updatedTags.length > tags.length) {
+        for (i = tags.length; i< updatedTags.length; i++){
+          // add tag
+          ops.push({"op": "add", "path": "/tags/"+i, "value": updatedTags[i]});
+        }
+      }
+      return m.request({
+        method: "PATCH",
+        url: "/v1/docs/"+id,
+        data: ops
+      });
+    });
+  };
 }());

@@ -13,27 +13,25 @@ vm.action = m.route.param("action");
     vm.readOnly = true;
     vm.contentType = m.prop("");
     vm.updatedTags = m.prop("");
+    vm.content = "";
+    vm.tags = [];
     try {
       vm.ext = vm.id().match(/\.(.+)$/)[1];
     } catch(e) {
       vm.ext = "";
     }
+    
+    // Retrieve single document & populate
     vm.getDoc = function(cb){
       vm.doc = Doc.get(vm.id());
       vm.doc.then(function(doc){
         vm.content = doc.data;
         vm.tags = doc.tags;
+        vm.updatedTags(vm.tags.filter(function(t){return !/^\$/.test(t)}).join(", "));
       }, vm.flashError);
     };
-    vm.viewDocument = function(){
-      if (vm.ext === "md" && vm.id().match(new Regexp("^"+vm.dir+"\/md\/"))) {
-        // If editing a documentation page, go back to the guide.
-        m.route("/guide/"+vm.id().replace(/\.md$/, "").replace(new Regexp("^"+vm.dir+"\/md\/"), ""));
-      } else {
-        m.route("/document/view/"+vm.id());
-      }
-    };
-    vm.tags = [];
+    
+    // Reset some properties based on action
     switch (vm.action) {
       case 'create':
         vm.readOnly = false;
@@ -47,26 +45,25 @@ case 'view':
         vm.getDoc();
         break;
     }
-    vm.editTagsDialogCfg = {
-      title: "Edit Tags",
-      id: "edit-tags-modal",
-      action: function(){
-        // TODO
-        console.log(vm.updatedTags());
-      },
-      actionText: "Update",
-      content: m("input", {
-            type: "text", 
-            class:"form-control", 
-            onchange: m.withAttr("value", vm.updatedTags),
-            placeholder: "Enter comma-separated tags..."
-          })
+    
+    // View document in editor
+    vm.viewDocument = function(){
+      if (vm.ext === "md" && vm.id().match(new RegExp("^"+vm.dir+"\/md\/"))) {
+        // If editing a documentation page, go back to the guide.
+        m.route("/guide/"+vm.id().replace(/\.md$/, "").replace(new Regexp("^"+vm.dir+"\/md\/"), ""));
+      } else {
+        m.route("/document/view/"+vm.id());
+      }
     };
+    
+    // Set current document editable
     vm.edit = function(){
       vm.editor.setReadOnly(false);
       vm.action = "edit";
       vm.flash("");
     };
+    
+    // Save document
     vm.save = function(){
       var doc = {};
       doc.id = vm.id();
@@ -79,7 +76,7 @@ vm.viewDocument();
         }, vm.flashError);
       };
       if (vm.action === "create") {
-        doc.id = vm.dir+"/"+vm.id();
+        doc.id = vm.id();
         vm.id(doc.id);
         Doc.get(doc.id)
           .then(function(){
@@ -91,17 +88,16 @@ } else {
         put();
       }
     };
+    
+    // Delete Document
     vm.delete = function(){
-      var msg = "Do you want to delete document '"+vm.id()+"'?";
-      if (confirm(msg)) {
-        Doc.delete(vm.id()).then(function(){
-          LS.flash({type: "success", content: "Document '"+vm.id()+"' deleted successfully."});
-          m.route("/info");
-        }, vm.flashError);
-      } else {
-        m.route("/document/view/"+vm.id());
-      }
+      Doc.delete(vm.id()).then(function(){
+        LS.flash({type: "success", content: "Document '"+vm.id()+"' deleted successfully."});
+        m.route("/info");
+      }, vm.flashError);
     };
+    
+    // Cancel editing
     vm.cancel = function(){
       if (vm.action === "create"){
         m.route("/info");
@@ -109,6 +105,21 @@ } else {
         vm.viewDocument();
       }
     };
+    
+    // Patch document (update tags)
+    vm.patch = function(){
+      var sysTags = vm.tags.filter(function(t){return /^\$/.test(t)});
+      var newTags = sysTags.concat(vm.updatedTags().split(/,\s*/));
+      Doc.patch(vm.id(), newTags).then(function(){
+        LS.flash({type: "success", content: "Tags for document '"+vm.id()+"' updated successfully."});
+        Info.get().then(function(info){
+          app.system = info;
+          vm.viewDocument();
+        });
+      }, vm.flashError);
+    };
+    
+    // Populate tools based on current action
     vm.tools = function(){
       if (app.system.read_only) {
         return [];
@@ -121,8 +132,8 @@ switch (vm.action){
         case "view":
           return [
             {title: "Edit Content", icon: "edit", action: vm.edit},
-            {title: "Edit Tags", icon: "tags", action: function(){$("#edit-tags-modal").modal()}},
-            {title: "Delete", icon: "trash", action: vm.delete}
+            {title: "Edit Tags", icon: "tags", action: u.showModal("#edit-tags-modal")},
+            {title: "Delete", icon: "trash", action: u.showModal("#delete-document-modal")}
           ];
         default:
           return [
@@ -132,12 +143,43 @@ ];
       }
     };
   };
+  
+  // Module main view
   app.document.main = function(){
     var vm = app.document.vm;
     var titleLeft = vm.id();
     var titleRight = m("span.pull-right", vm.tags.map(function(t){return u.taglink(t);}));
+    // Delete confirmation dialog
+    var deleteDialogCfg = {
+      title: "Delete Document",
+      id: "delete-document-modal",
+      action: vm.delete,
+      actionText: "Delete",
+      content: m("p", "Do you want to delete document '"+vm.id()+"'?")
+    };
+    // Configuration for the Edit Tags dialog
+    var editTagsDialogCfg = {
+      title: "Add/Edit User Tags",
+      id: "edit-tags-modal",
+      action: vm.patch,
+      actionText: "Update",
+      content: m("div", [
+        m("input", {
+            type: "text", 
+            class:"form-control", 
+            onchange: m.withAttr("value", vm.updatedTags),
+            value: vm.updatedTags(),
+            placeholder: "Enter comma-separated tags..."
+        }),
+        m("div.tip", [
+          m("p", "Tip") ,
+          m("p", "Each user tag can contain letters, numbers, and any of the following special characters:"),
+        m("p", "?, ~, :, ., @, #, ^, !, +, _, or -")
+        ])
+      ])
+    };
     if (vm.action === "create"){
-        titleLeft = m("span", [vm.dir+"/",m("input", {
+        titleLeft = m("span", [m("input", {
           placeholder: "Document ID",
           onchange: m.withAttr("value", function(value){
             vm.id(value);
@@ -155,11 +197,12 @@ })]);
     }
     var title = m("span",[titleLeft, titleRight]);
     return m("div", [
-      u.modal(vm.editTagsDialogCfg),
+      u.modal(deleteDialogCfg),
+      u.modal(editTagsDialogCfg),
       m(".row", [u.toolbar({links: vm.tools()})]),
       m(".row", [u.panel({title: title, content:app.editor.view(vm)})])
     ]);
   };
   
-    u.layout(app.document);
+  u.layout(app.document);
 }());

@@ -165,7 +165,8 @@ ]);
   };
 
   u.taglink = function(tag) {
-    return m("span.label.label-primary", 
+    var color = /^\$/.test(tag) ? "warning" : "primary";
+    return m("span.tag-label.label.label-"+color, 
       [m("i.fa.fa-tag"), " ", m("a", {href: "/tags/"+tag, config:m.route}, tag)]);
   };
   
@@ -204,13 +205,9 @@ return "";
     }
   };
   
-  /**
-   * obj:
-   * - id
-   */
-  u.showModal = function(id){
-    return function(el, isInitialized){
-      $(id).modal();
+  u.showModal = function(sel){
+    return function(){
+      $(sel).modal();
     };
   };
   
@@ -236,7 +233,7 @@ ]),
             m(".modal-body", [obj.content]),
             m(".modal-footer", [
               m("button.btn.btn-default[data-dismiss='modal']", "Close"),
-              m("button.btn.btn-default[data-dismiss='modal']", {onclick: obj.action}, obj.actionText)
+              m("button.btn.btn-primary[data-dismiss='modal']", {onclick: obj.action}, obj.actionText)
             ])
           ])
         ])

@@ -122,7 +122,7 @@ span.ext, span.kwd {
   font-weight: bold;
 }
 
-span.label-primary {
+span.tag-label {
   margin: auto 2px;
   font-weight: normal;
   &:hover {

@@ -1867,14 +1867,14 @@ span.ext,
 span.kwd {
   font-weight: bold;
 }
-span.label-primary {
+span.tag-label {
   margin: auto 2px;
   font-weight: normal;
 }
-span.label-primary a {
+span.tag-label a {
   color: #efefef;
 }
-span.label-primary a:hover {
+span.tag-label a:hover {
   color: #fff;
   text-decoration: none;
 }

@@ -1,10 +1,6 @@ 
 import json, db_sqlite, strutils, pegs, asyncdispatch, asynchttpserver2, times, logging, math, sqlite3
 import types, queries, contenttypes
 
-proc dbg*(args: varargs[string, `$`]) =
-  if logging.level <= lvlDebug:
-    echo "DEBUG - "&args.join(" ")
-
 proc dbQuote*(s: string): string =
   result = "'"
   for c in items(s):
@@ -48,7 +44,7 @@ if options.limit > 0:
     result = result & "LIMIT " & $options.limit & " "
     if options.offset > 0:
       result = result & "OFFSET " & $options.offset & " "
-  dbg(result)
+  debug(result.replace("$", "$$"))
 
 proc prepareSelectTagsQuery*(options: QueryOptions): string =
   result = "SELECT tag_id, COUNT(document_ID) "
@@ -60,7 +56,7 @@ if options.orderby.len > 0:
     result = result & "ORDER BY " & options.orderby&" " 
   if options.limit > 0:
     result = result & "LIMIT " & $options.limit & " "
-  dbg(result)
+  debug(result.replace("$", "$$"))
 
 proc prepareJsonDocument*(store:Datastore, doc: TRow, cols:seq[string]): JsonNode =
   var raw_tags = store.db.getAllRows(SQL_SELECT_DOCUMENT_TAGS, doc[0])
@@ -83,11 +79,9 @@ res.add(("tags", %tags))
   return %res
 
 proc toPlainText*(s: string): string =
-  let subs = @[
-    (pattern: peg"""\<\/?[^<>]+\>""", repl: ""),
-    (pattern: peg"""{[_*/+!=?%$^-]+} {(!$1 .)+} $1""", repl: "$2")
-  ]
-  return s.parallelReplace(subs)
+  var tags = peg"""'<' [^<>]+ '>'"""
+  var markup = peg"""{[_*/+!=?%$^~]+} {(!$1 .)+} $1"""
+  return s.replace(tags).replacef(markup, "$2")
 
 proc checkIfBinary*(binary:int, contenttype:string): int =
   if binary == -1 and contenttype.isBinary:
@@ -116,9 +110,9 @@ stderr.writeln(msg)
   quit(code)
 
 proc resError*(code: HttpCode, message: string, trace = ""): Response =
-  warn(message)
+  warn(message.replace("$", "$$"))
   if trace.len > 0:
-    dbg(trace)
+    debug(trace.replace("$", "$$"))
   result.code = code
   result.content = """{"error":"$1"}""" % message
   result.headers = ctJsonHeader()