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LSPS Documentation
Charts

Important: Chart components are based on Vaadin Charts, which are developed by a third party. Before designing your charts, make sure to obtain the respective licenses for Vaadin Charts.

Chart components render data as defined by their plotting options; hence you need to define these:

  • The data is defined as data series or data values depending on the chart.
  • Plotting is defined in the plotting options of each the chart or data series.

Generic Chart Features

All charts can be redrawn on request and trigger an action, when the user clicks a data point in the chart.

Redrawing Charts

To redraw a chart, call the refresh() method on the chart.

Performing Actions on Chart Click

To handle a click on a chart item, define the onPointClick property of the chart with its setter method setOnPointClick(). The property is a closure with the ChartPointClickEvent produced by the click as its input parameter.

Typically, you will define the action on the Init tab of the component so the clicks are processed from the moment the chart is displayed.

myChart.setOnPointClick( 
  {
    click:ChartPointClickEvent ->
      clickedSeries.setCaption(click.series)
  }
);

If you need to pass further data about the data item, define payload on the data series items: The payload is passed as the payload property of the ChartPointClickEvent.

[
  new ListDataSeries(
    [
       new ListDataSeriesItem( 1 , "This is some payload."),
       new ListDataSeriesItem( 5 , "This is also some payload.")
    ]
  )
]
PointClickWithPayload.png
Item payload sent to a popup and displayed on click

Pie Chart (forms::PieChart)

The Pie Chart component is plotted as a pie chart; its data is defined in a list of PieSliceSeries. Each PieSliceSeries is plotted as its own pie with a set of PieSlices with the data. The pies are stack on each other in the order they are arranged in the data set. Mind that in such cases you will like need to adjust the plotting of the data series in order to make the pies visible.

Creating a Pie Chart

To create a pie chart, do the following:

  1. Insert the pie chart component into your form.
  2. Define the pie data series:
    • either in the Pie slice series field of the Properties view
    • or using the addPieSliceSeries() method on a pie chart

      Data for a pie chart with a single series

      def PieSliceSeries mySeries := new PieSliceSeries("My only series", [
               new forms::PieSlice("Big slice", 50, "Business data", new Color("#162955")),
               new forms::PieSlice("Middle slice", 30, "Business data", new Color("#4F628E")),
               new forms::PieSlice("Small slice", 20, "Business data", new Color("#7887ab"))
      ]);
      [ mySeries ]
      
      simplePieChart.png

Adding a Pie Data Series on Action

To add a data series when the user or the system performs some action, run the addPieSliceSeries() method on the chart from the appropriate location, such as, Click Listener of a button.

{ e -> myAlreadyRenderedPeiChart.addPieSliceSeries(myPieSliceSeries)}

Plotting Pie Slice Series

To define how individual pie slice series are presented, define their plotting options as a PlotOptionsPie object and assign it to the series.

In the PlotOptionsPie object, you can define the following properties:

  • innerSize: distance of the inner border from the center (size of the "hole" in the donut chart)

    You can define it either in percent relative to the pie size or in pixels as Integer value.

  • dataLabels: formatting of slice labels
  • startAngle: rotation of the chart series (angle where the first slice starts)

    0 is the top; 90 is right;

  • size: perimeter of the chart series

    You can define it either in percent relative to the plot area or in pixels as Integer value.

  • shadow: shadow behind the chart series
  • center: position of the chart center relative to left-upper corner of the component slot
  • endAngle: degree that marks the end of the chart

    0 is the top; 90 is right; null and the default value result in startAngle + 360.

  • showInLegend: whether the slices are included in the chart legend
    def PlotOptionsPie mySeriesPlotting := new PlotOptionsPie(
                          //inner border is at 40% of the perimeter size:
                          innerSize -> new AttributeSize("40%"),
                          //rotation:
                          startAngle -> 90,
                          //chart series size:
                          size -> new AttributeSize(350),
                          shadow -> true,
                          borderWidth -> 5,
                          //position of the series:
                          center -> new AttributeCenter(0, 0),
                          endAngle -> 180,
                          showInLegend -> true);
    mySeries.plotOptions := mySeriesPlotting;
    
    customizedPlotPieChart.png

Formatting Pie Slice Labels

To define formatting of data labels on data series of Pie Charts, define the dataLabels property on the pie data series as a PieDataLabels object.

Formatting expression can access the following variables:

  • percentage: percentage the slice takes
  • point: pie slice object
  • series: pie series object
  • total: total of the series
  • formatter: label template
  • format: label template that overrides formatter

    From format, the variables are available on point object, for example {point.percentage}.

dataLabels -> new PieDataLabels(
    //javascript code used as label:
    formatter -> "'Percentage: ' + this.percentage +
    '<br>Point name: '+ this.point.name +
    '<br>Series: ' + this.series.name +
    '<br>Total: ' + this.total +
    '<br>x: ' + this.x ",
    //formatter -> "'this.x'",
    //rotation in degrees counterclockwise:
    rotation -> 45,
    format -> "Name: {point.name} Percentage: {point.percentage} Y: {point.y}",
    enabled -> true,
    color -> new Color(8, 8, 8),
    //Distance of the data label from the slice edge; can be also negative:
    distance -> 150)

Cartesian Chart (forms::CartesianChart)

Cartesian Charts serve to plot data as line, bar, area, or bubble charts.

The charts can plot multiple data sets, called data series, with different plotting. Data series are groups of related data that represent one graph.

When creating a data series, pick the data series type depending on the data values:

  • ListDataSeries: a sole decimal value
  • DecimalDataSeries: a decimal and, a range or another decimal values
  • CategoryDataSeries: a category, and ranges or sole decimal values
  • TimeDataSeries: a point in time, and a sole decimal value or range

The data in a series is defined as a list of data-series items. Each type of data series can work only with data items of the respective type: CategoryDataSeries can contain only CategoryDataSeriesItems; DecimalDataSeries can contain only DecimalDataSeriesItems; ListDataSeries can contain only ListDataSeriesItems.

The data series items can hold ranges or values where applicable:

  • ListDataSeriesItems: a sole decimal value, for example, new ListDataSeriesItem(0.21); the value is the y value and x is the index of the item in the list.
  • CategoryDataSeriesItems:
    • a decimal value with an optional name; for example, new CategoryDataSeriesItem("Greenland", 56196)
    • or a range of values with an optional name; for example, new CategoryDataSeriesItem("Greenland", 56196, 56239).
  • DecimalDataSeriesItems :
    • decimals with the x and y coordinates, for example, new DecimalDataSeriesItem(2, 5)
    • or a range of decimal values; for example,new DecimalDataSeriesItem(7, 3, 8)
  • TimeDataSeriesItems:
    • date with a value, for example, new TimeDataSeriesItem(now() + seconds(1), 7)
    • or a range and a date; for example,new TimeDataSeriesItem(now(), 1, 3)

Each data series defines its plotting options; hence, each data series can be plotted differently from the others: override the plot options if you want to change the plotting.

Example data series

new CategoryDataSeries (
  [
    new CategoryDataSeriesItem("Greenland", 56196, 56239),
    new CategoryDataSeriesItem("China", 1388232693, 194202093),
    new CategoryDataSeriesItem("India", 1342512706, 1358354355),
    new CategoryDataSeriesItem("USA", 326474013, 328857273)
  ]
);

Adding a Cartesian Data Series on Action

To add a data series when the user or the system performs some action, run the addDataSeries() method on the chart from the appropriate location, such as, Click Listener of a button.

{ e -> myRenderedChart.addDataSeries(myCatesianSeries)}

Adding a Data Series Item on Action

To add a data series item to a data series when the user or the system performs some action, run the addItem() method on the data series from the appropriate location, such as, Click Listener of a button.

{ e -> myAlreadyRenderedDataSeries.addItem(new ListDataSeriesItem(5, "This is new item with value 5."))}

Changing the Current Data Series

To use another data series in a Cartesian chart, call the setDataSeries() method on the chart.

Changing Plotting of a Cartesian Chart Series

Each type of data series has default plotting which depends on the data in their items. Note that data series items can define their default plot options:

  • ListDataSeriesItem: PlotOptionsLine
  • CategoryDataSeriesItem: PlotOptionsColumn
  • DecimalDataSeriesItem and TimeDataSeries: with range (low and high) PlotOptionsLineArea; with values PlotOptionsLine

If you are not happy with the default plotting, you can adjust plotting of individual series, by setting the plotOptions property of the data series.

Note that some plotting options apply only to some types of data series item: for example, if you are working with series items that have decimals values only, it is not possible to use the Bubble plotting since this plotting requires a range to define the size of the Bubble marker.

You can plot the series items as the following:

  • PlotOptionsColumn: bar chart plotting

    It applies to items with a single value and CategoryDataSeriesItems with a range.

  • PlotOptionsBubble: bubble chart plotting (requires range data series items; items with values are ignored)

    It applies to items with ranges.

  • PlotOptionsScatter: scatter chart plotting (requires value data series items; items with ranges are ignored)

    It applies to items with values.

  • PlotOptionsLine: line chart plotting

    It applies to items with values.

  • PlotOptionsLineArea: line-area chart plotting (area below the line is filled)

    It applies to items with values.

Defining plotOptions property of a data series

myDataSeries.plotOptions := new PlotOptionsLineArea(spline -> true, range -> true)

Changing Plotting of Point Markers on Scatter, Line and Line Area Charts

To change the plotting of point markers on Scatter, Line and Line Area Charts, set the marker property of the plot options:

//changing marker plotting:
myDataSeries.plotOptions := new PlotOptionsScatter(marker -> Marker.diamond);
//"smoothing" out the graph line:
itemListDataSeries.plotOptions := new PlotOptionsLine(spline -> true);
//setting graph line color:
itemListDataSeries.plotOptions.color := new Color(0,0,0);
//to interrupt the flow of the graph, set the item where to interrupt to null:
def ListDataSeries dataSeries := new ListDataSeries([1, 2, 3, 2, null, 4, 6]);
//to stack bars of a bar chart on the y axis behind each other,
//set the plotOptions.stacked to true:
def forms::PlotOptionsColumn plotOptionsColumn := new forms::PlotOptionsColumn();
plotOptionsColumn.stacked := true;:

Polar Chart (forms::PolarChart)

Since Polar chart is a special case of the Cartesian chart, the uses the same types of data series just like in the Cartesian Chart and has the same plotting options.

Creating a Polar Chart

To create a polar chart, insert the component to your form and define its data series. Any other required properties will use their default values.

Gauge Chart (forms::GaugeChart)

The Gauge Chart component has a single decimal as its value.

To define an action to double-clicking the point, set the onPointClick field of the Gauge Chart with the setter method:

c.setOnPointClick({ e:ChartPointClickEvent -> doSomething()})

Creating a Gauge Chart

To create a gauge chart, do the following:

  1. Insert the gauge chart component into your form.
  2. Define the Properties:
    • Value: where the needle should point
    • Value name: value description displayed when hovering over the needle
    • Y Axis: axis

Note that ticks have by default 0 length and are hence not displayed.

Example axis definition

new Axis(
  min -> 0,
  max -> 100,
 
  tickLength -> 0,
  tickInterval -> 5,
  tickWidth -> 2,
  tickColor -> new Color(0, 100, 100, 1),
 
  plotBands -> [
    new forms::PlotBand(from -> 180, to -> 240, color -> new Color(255, 51, 102, 0.8)),
    new forms::PlotBand(from -> 130, to -> 180, color -> new Color(255, 255, 102, 1))
  ]
);
GaugeRendered.png
To remove the ticks, set gridLineWidth to 0.

Axes (forms::Axis)

Axes are rendered in some default way for each type of data series in your chart

Changing Axis Range

To change the range of the chart axis, set its min and max properties.

//new axis with its maximum and minimum set:
new Axis(
min -> 0,
max -> 240)

Axis Values

By default, both the axes display decimals as their values: This is intuitive for the y axis: after all, we are visualizing numbers, but might not be the required values for your x axis.

Note that the following values are used on the x axis by default:

  • for ListDataSeriesItem and CategoryDataSeriesItem, the index of the item in the List
  • for DateDataSeriesItem, the date in epoch milliseconds
  • for DecimalDataSeriesItem, the date in epoch milliseconds

These properties can be overridden in the axis properties or with the addXAxis() or addYAxis() method of the chart.

Changing Axis Values

If you want to change the values on an axis, define a new axis in the axis properties or with the addXAxis() or addYAxis() method of the chart.

new Axis('type' -> AxisType.category, categories -> ["My first name", null, "My third name"])

If you want to change only the value types on the axis, it is enough to change the AxisType. For example, if you want to display Date object as dates on the axis, define a new axis of the datetime type: `new Axis('type' -> AxisType.datetime)`.

Creating Multiple Axis

You can add multiple axes to you chart with the addXAxis() or addYAxis() method: by default such axes are rendered next to each other. You might want to render one of the Axis on the opposite side of the chart: to do so, set its opposite property to true.

def forms::Axis yAxisTemperature := new forms::Axis();
yAxisTemperature.labels := new forms::ChartLabels(format -> "{value} °C");
yAxisTemperature.title := "Temperature";
yAxisTemperature.max := 20;
yAxisTemperature.min := -55;
chart.addYAxis(yAxisTemperature);
def forms::Axis yAxisPressure := new forms::Axis();
yAxisPressure.labels := new forms::ChartLabels(format -> "{value} kPa");
yAxisPressure.opposite := true;
yAxisPressure.title := "Pressure";
yAxisPressure.max := 102;
yAxisPressure.min := 20;
chart.addYAxis(yAxisPressure);