diff --git a/src/octoprint/static/js/app/main.js b/src/octoprint/static/js/app/main.js
index 4dc14dbe..5f3c85f9 100644
--- a/src/octoprint/static/js/app/main.js
+++ b/src/octoprint/static/js/app/main.js
@@ -498,36 +498,32 @@ $(function() {
         //~~ view model binding
 
         settingsViewModel.requestData(function() {
-            ko.applyBindings(settingsViewModel, document.getElementById("settings_dialog"));
+            var viewModelsToInit = additionalViewModels.concat([
+                [settingsViewModel, document.getElementById("settings_dialog")],
+                [connectionViewModel, document.getElementById("connection_wrapper")],
+                [printerStateViewModel, document.getElementById("state_wrapper")],
+                [gcodeFilesViewModel, document.getElementById("files_wrapper")],
+                [temperatureViewModel, document.getElementById("temp")],
+                [controlViewModel, document.getElementById("control")],
+                [gcodeViewModel, document.getElementById("gcode")],
+                [terminalViewModel, document.getElementById("term")],
+                [navigationViewModel, document.getElementById("navbar")],
+                [appearanceViewModel, document.getElementsByTagName("head")[0]],
+                [printerStateViewModel, document.getElementById("drop_overlay")],
+                [logViewModel, document.getElementById("logs")],
+                [timelapseViewModel, document.getElementById("timelapse")],
+                [slicingViewModel, document.getElementById("slicing_configuration_dialog")]
+            ]);
 
-            ko.applyBindings(connectionViewModel, document.getElementById("connection_wrapper"));
-            ko.applyBindings(printerStateViewModel, document.getElementById("state_wrapper"));
-            ko.applyBindings(gcodeFilesViewModel, document.getElementById("files_wrapper"));
-            ko.applyBindings(temperatureViewModel, document.getElementById("temp"));
-            ko.applyBindings(controlViewModel, document.getElementById("control"));
-            ko.applyBindings(terminalViewModel, document.getElementById("term"));
-            var gcode = document.getElementById("gcode");
-            if (gcode) {
-                gcodeViewModel.initialize();
-                ko.applyBindings(gcodeViewModel, gcode);
-            }
-            //ko.applyBindings(settingsViewModel, document.getElementById("settings_dialog"));
-            ko.applyBindings(navigationViewModel, document.getElementById("navbar"));
-            ko.applyBindings(appearanceViewModel, document.getElementsByTagName("head")[0]);
-            ko.applyBindings(printerStateViewModel, document.getElementById("drop_overlay"));
-            ko.applyBindings(logViewModel, document.getElementById("logs"));
+            // apply bindings
+            var rerenderControls = false;
+            _.each(viewModelsToInit, function(viewModelData) {
+                if (!Array.isArray(viewModelData) || viewModelData.length != 2) {
+                    return;
+                }
 
-            var timelapseElement = document.getElementById("timelapse");
-            if (timelapseElement) {
-                ko.applyBindings(timelapseViewModel, timelapseElement);
-            }
-
-            ko.applyBindings(slicingViewModel, document.getElementById("slicing_configuration_dialog"));
-
-            // apply bindings and signal startup
-            _.each(additionalViewModels, function(additionalViewModel) {
-                var viewModel = additionalViewModel[0];
-                var targets = additionalViewModel[1];
+                var viewModel = viewModelData[0];
+                var targets = viewModelData[1];
 
                 if (targets === undefined) {
                     return;
@@ -542,17 +538,30 @@ $(function() {
                 }
 
                 _.each(targets, function(target) {
-                    try {
-                        ko.applyBindings(viewModel, target);
-                    } catch (exc) {
-                        console.log("Could not apply bindings for additional view model " + viewModel + ": " + exc.message);
+                    if (target) {
+                        try {
+                            ko.applyBindings(viewModel, target);
+                        } catch (exc) {
+                            console.log("Could not apply bindings for additional view model " + viewModel + ": " + exc.message);
+                        }
+                    } else {
+                        console.log("Could not apply binding for view model " + viewModel + ", target does not exist");
                     }
                 });
 
                 if (viewModel.hasOwnProperty("onAfterBinding")) {
                     viewModel.onAfterBinding();
                 }
+
+                if (viewModel.hasOwnProperty("getAdditionalControls")) {
+                    controlViewModel.additionalControls = controlViewModel.additionalControls.concat(viewModel.getAdditionalControls());
+                    rerenderControls = true
+                }
             });
+
+            if (rerenderControls) {
+                controlViewModel.rerenderControls();
+            }
         });
 
         //~~ UI stuff
diff --git a/src/octoprint/static/js/app/viewmodels/control.js b/src/octoprint/static/js/app/viewmodels/control.js
index c12767cb..a66e5d3b 100644
--- a/src/octoprint/static/js/app/viewmodels/control.js
+++ b/src/octoprint/static/js/app/viewmodels/control.js
@@ -26,6 +26,9 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
 
     self.feedbackControlLookup = {};
 
+    self.controlsFromServer = [];
+    self.additionalControls = [];
+
     self.keycontrolActive = ko.observable(false);
     self.keycontrolHelpActive = ko.observable(false);
     self.keycontrolPossible = ko.computed(function() {
@@ -84,6 +87,11 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
         }
     };
 
+    self.rerenderControls = function() {
+        var allControls = self.controlsFromServer.concat(self.additionalControls);
+        self.controls(self._processControls(allControls))
+    };
+
     self.requestData = function() {
         $.ajax({
             url: API_BASEURL + "printer/command/custom",
@@ -96,7 +104,8 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
     };
 
     self._fromResponse = function(response) {
-        self.controls(self._processControls(response.controls));
+        self.controlsFromServer = response.controls;
+        self.rerenderControls();
     };
 
     self._processControls = function(controls) {
@@ -117,9 +126,49 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
         } else if (control.type == "section") {
             control.children = self._processControls(control.children);
         }
+
+        var js;
+        if (control.hasOwnProperty("javascript")) {
+            js = control.javascript;
+
+            // if js is a function everything's fine already, but if it's a string we need to eval that first
+            if (!_.isFunction(js)) {
+                control.javascript = function(data) {
+                    eval(js);
+                };
+            }
+        }
+
+        if (control.hasOwnProperty("enabled")) {
+            js = control.enabled;
+
+            // if js is a function everything's fine already, but if it's a string we need to eval that first
+            if (!_.isFunction(js)) {
+                control.enabled = function(data) {
+                    return eval(js);
+                }
+            }
+        }
+
         return control;
     };
 
+    self.isCustomEnabled = function(data) {
+        if (data.hasOwnProperty("enabled")) {
+            return data.enabled(data);
+        } else {
+            return self.isOperational() && self.loginState.isUser();
+        }
+    };
+
+    self.clickCustom = function(data) {
+        if (data.hasOwnProperty("javascript")) {
+            data.javascript(data);
+        } else {
+            self.sendCustomCommand(data);
+        }
+    };
+
     self.sendJogCommand = function(axis, multiplier, distance) {
         if (typeof distance === "undefined")
             distance = $('#jog_distance button.active').data('distance');
@@ -185,17 +234,17 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
     self.sendSelectToolCommand = function(data) {
         if (!data || !data.key()) return;
 
-        var data = {
+        var payload = {
             command: "select",
             tool: data.key()
-        }
+        };
 
         $.ajax({
             url: API_BASEURL + "printer/tool",
             type: "POST",
             dataType: "json",
             contentType: "application/json; charset=UTF-8",
-            data: JSON.stringify(data)
+            data: JSON.stringify(payload)
         });
     };
 
@@ -211,7 +260,7 @@ function ControlViewModel(loginStateViewModel, settingsViewModel) {
                 contentType: "application/json; charset=UTF-8",
                 data: JSON.stringify(data)
             })
-        }
+        };
         var data = undefined;
         if (command.type == "command" || command.type == "parametric_command" || command.type == "feedback_command") {
             // single command
diff --git a/src/octoprint/templates/tabs/control.jinja2 b/src/octoprint/templates/tabs/control.jinja2
index 93c54ef6..1c0d78a1 100644
--- a/src/octoprint/templates/tabs/control.jinja2
+++ b/src/octoprint/templates/tabs/control.jinja2
@@ -105,12 +105,12 @@
 </script>
 <script type="text/html" id="customControls_commandTemplate">
     <form class="form-inline">
-        <button class="btn" data-bind="text: name, enable: $root.isOperational() && $root.loginState.isUser(), click: function() { $root.sendCustomCommand($data) }"></button>
+        <button class="btn" data-bind="text: name, enable: $root.isCustomEnabled($data), click: function() { $root.clickCustom($data) }"></button>
     </form>
 </script>
 <script type="text/html" id="customControls_feedbackCommandTemplate">
     <form class="form-inline">
-        <button class="btn" data-bind="text: name, enable: $root.isOperational() && $root.loginState.isUser(), click: function() { $root.sendCustomCommand($data) }"></button> <span data-bind="text: output"></span>
+        <button class="btn" data-bind="text: name, enable: $root.isCustomEnabled($data), click: function() { $root.clickCustom($data) }"></button> <span data-bind="text: output"></span>
     </form>
 </script>
 <script type="text/html" id="customControls_feedbackTemplate">
@@ -124,7 +124,7 @@
         <label data-bind="text: name"></label>
         <input type="text" class="input-small" data-bind="attr: {placeholder: name}, value: value">
         <!-- /ko -->
-        <button class="btn" data-bind="text: name, enable: $root.isOperational() && $root.loginState.isUser(), click: function() { $root.sendCustomCommand($data) }"></button>
+        <button class="btn" data-bind="text: name, enable: $root.isCustomEnabled($data), click: function() { $root.clickCustom($data) }"></button>
     </form>
 </script>
 <script type="text/html" id="customControls_emptyTemplate"><div></div></script>