feat(singlestat): add serie name as an value option

closes #4740

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Enhancements
 * **Login**: Adds option to disable username/password logins, closes [#4674](https://github.com/grafana/grafana/issues/4674)
+* **SingleStat**: Add seriename as option in singlestat panel, closes [#4740](https://github.com/grafana/grafana/issues/4740)
 
 
 # 3.1.0 stable (unreleased)

public/app/plugins/panel/singlestat/editor.html

@@ -16,7 +16,10 @@
 					Value
 				</li>
 				<li>
-					<select class="input-small tight-form-input" ng-model="ctrl.panel.valueName" ng-options="f for f in ['min','max','avg', 'current', 'total']" ng-change="ctrl.render()"></select>
+					<select class="input-small tight-form-input"
+            ng-model="ctrl.panel.valueName"
+            ng-options="f for f in ctrl.valueNameOptions"
+            ng-change="ctrl.render()"></select>
 				</li>
 				<li class="tight-form-item">
 					Postfix

public/app/plugins/panel/singlestat/module.ts

@@ -19,6 +19,9 @@ class SingleStatCtrl extends MetricsPanelCtrl {
   fontSizes: any[];
   unitFormats: any[];
   invalidGaugeRange: boolean;
+  panel: any;
+  events: any;
+  valueNameOptions: any[] = ['min','max','avg', 'current', 'total', 'name'];
 
   // Set and populate defaults
   panelDefaults = {
@@ -186,7 +189,11 @@ class SingleStatCtrl extends MetricsPanelCtrl {
       var lastPoint = _.last(this.series[0].datapoints);
       var lastValue = _.isArray(lastPoint) ? lastPoint[0] : null;
 
-      if (_.isString(lastValue)) {
+      if (this.panel.valueName === 'name') {
+        data.value = 0;
+        data.valueRounded = 0;
+        data.valueFormated = this.series[0].alias;
+      } else if (_.isString(lastValue)) {
         data.value = 0;
         data.valueFormated = lastValue;
         data.valueRounded = 0;

public/app/plugins/panel/singlestat/specs/singlestat-specs.ts

@@ -51,6 +51,22 @@ describe('SingleStatCtrl', function() {
     });
   });
 
+  singleStatScenario('showing serie name instead of value', function(ctx) {
+    ctx.setup(function() {
+      ctx.datapoints = [[10,1], [20,2]];
+      ctx.ctrl.panel.valueName = 'name';
+    });
+
+    it('Should use series avg as default main value', function() {
+      expect(ctx.data.value).to.be(0);
+      expect(ctx.data.valueRounded).to.be(0);
+    });
+
+    it('should set formated falue', function() {
+      expect(ctx.data.valueFormated).to.be('test.cpu1');
+    });
+  });
+
   singleStatScenario('MainValue should use same number for decimals as displayed when checking thresholds', function(ctx) {
     ctx.setup(function() {
       ctx.datapoints = [[99.999,1], [99.99999,2]];