feat: add support for stacking in timeseries panel

Signed-off-by: Martin Chodur <m.chodur@seznam.cz>

decoder/timeseries.go

@@ -11,6 +11,7 @@ import (
 var ErrInvalidGradientMode = fmt.Errorf("invalid gradient mode")
 var ErrInvalidLineInterpolationMode = fmt.Errorf("invalid line interpolation mode")
 var ErrInvalidTooltipMode = fmt.Errorf("invalid tooltip mode")
+var ErrInvalidStackMode = fmt.Errorf("invalid stack mode")
 var ErrInvalidAxisDisplay = fmt.Errorf("invalid axis display")
 var ErrInvalidAxisScale = fmt.Errorf("invalid axis scale")
 
@@ -177,6 +178,7 @@ func (timeseriesPanel DashboardTimeSeries) target(t Target) (timeseries.Option,
 type TimeSeriesVisualization struct {
  GradientMode string `yaml:"gradient_mode,omitempty"`
  Tooltip string `yaml:"tooltip,omitempty"`
+ Stack string `yaml:"stack,omitempty"`
  FillOpacity *int `yaml:"fill_opacity,omitempty"`
  PointSize *int `yaml:"point_size,omitempty"`
  LineInterpolation string `yaml:"line_interpolation,omitempty"`
@@ -213,6 +215,14 @@ func (timeseriesViz *TimeSeriesVisualization) toOptions() ([]timeseries.Option,
 
  opts = append(opts, gradient)
  }
+ if timeseriesViz.Stack != "" {
+ stack, err := timeseriesViz.stackOption()
+ if err != nil {
+ return nil, err
+ }
+
+ opts = append(opts, stack)
+ }
  if timeseriesViz.LineInterpolation != "" {
  interpolationOpt, err := timeseriesViz.lineInterpolationOption()
  if err != nil {
@@ -280,6 +290,22 @@ func (timeseriesViz *TimeSeriesVisualization) tooltipOption() (timeseries.Option
  return timeseries.Tooltip(mode), nil
 }
 
+func (timeseriesViz *TimeSeriesVisualization) stackOption() (timeseries.Option, error) {
+ var mode timeseries.StackMode
+ switch timeseriesViz.Stack {
+ case "normal":
+ mode = timeseries.Normal
+ case "percent":
+ mode = timeseries.Percent
+ case "none":
+ mode = timeseries.Unstacked
+ default:
+ return timeseries.Stack(mode), ErrInvalidStackMode
+ }
+
+ return timeseries.Stack(mode), nil
+}
+
 type TimeSeriesAxis struct {
  SoftMin *int `yaml:"soft_min,omitempty"`
  SoftMax *int `yaml:"soft_max,omitempty"`

decoder/timeseries_test.go

@@ -335,6 +335,57 @@ func TestTimeSeriesTooltipRejectsInvalidValues(t *testing.T) {
  req.Equal(ErrInvalidTooltipMode, err)
 }
 
+func TestTimeSeriesStackCanBeDecided(t *testing.T) {
+ testCases := []struct {
+ mode string
+ expectedMode timeseries.StackMode
+ }{
+ {
+ mode: "none",
+ expectedMode: timeseries.Unstacked,
+ },
+ {
+ mode: "normal",
+ expectedMode: timeseries.Normal,
+ },
+ {
+ mode: "percent",
+ expectedMode: timeseries.Percent,
+ },
+ }
+
+ for _, testCase := range testCases {
+ tc := testCase
+
+ t.Run(tc.mode, func(t *testing.T) {
+ req := require.New(t)
+
+ viz := TimeSeriesVisualization{
+ Stack: tc.mode,
+ }
+ opts, err := viz.toOptions()
+
+ req.NoError(err)
+
+ tsPanel, err := timeseries.New("", opts...)
+
+ req.NoError(err)
+ req.Equal(string(tc.expectedMode), tsPanel.Builder.TimeseriesPanel.FieldConfig.Defaults.Custom.Stacking.Mode)
+ })
+ }
+}
+
+func TestTimeSeriesStackRejectsInvalidValues(t *testing.T) {
+ req := require.New(t)
+
+ viz := TimeSeriesVisualization{
+ Stack: "invalid",
+ }
+ _, err := viz.toOptions()
+
+ req.Equal(ErrInvalidStackMode, err)
+}
+
 func TestTimeSeriesAxisSupportsDisplay(t *testing.T) {
  testCases := []struct {
  value string

timeseries/timeseries.go

@@ -28,6 +28,18 @@ const (
  NoSeries TooltipMode = "none"
 )
 
+// StackMode configures mode of series stacking.
+type StackMode string
+
+const (
+ // Unstacked will not stack series
+ Unstacked StackMode = "none"
+ // Normal will stack series as absolute numbers
+ Normal StackMode = "normal"
+ // Percent will stack series as percents
+ Percent StackMode = "percent"
+)
+
 // LineInterpolationMode defines how Grafana interpolates series lines when drawn as lines.
 type LineInterpolationMode string
 
@@ -189,6 +201,15 @@ func LineWidth(value int) Option {
  }
 }
 
+// Stack defines if the series should be stacked and using which mode (default not stacked). the opacity level of the series. The lower the value, the more transparent.
+func Stack(value StackMode) Option {
+ return func(timeseries *TimeSeries) error {
+ timeseries.Builder.TimeseriesPanel.FieldConfig.Defaults.Custom.Stacking.Mode = string(value)
+
+ return nil
+ }
+}
+
 // FillOpacity defines the opacity level of the series. The lower the value, the more transparent.
 func FillOpacity(value int) Option {
  return func(timeseries *TimeSeries) error {