PieChart

The structure of a PieChart class is as follows:

public class PieChart: IChartPoint, IPieStyles
{
    public string title { get; set; } = "without title";
    public VisibilityZoomLevels visibilityZoomLevels { get; set; } = new VisibilityZoomLevels();
    public int dimension { get; set; }
    public int scaling { get; set; } = 100;
    public int  fontSize { get; set; } = 6;
    public int expandedIndex { get; set; } = -1;    //slice index to be expanded, -1 means no slice is expanded
    public PieStyle? styles { get; set; } = null;
    public object paramOrValues { get; set; }       //values for pie chart or parameter ${parameterValues}
    public object paramOrLabels { get; set; }       //labels for pie chart or parameter ${parameterLabels}
    public object paramOrColors { get; set; }       //colors for pie chart or parameter ${parameterColors}
}

Where the properties paramOrValues, paramOrLabels, paramOrColors can accept arrays of values ​​(numeric and text) or can accept template literals/templates strings, but without backtick (`) characters.

The "paramOr..." properties are of type object, and their meaning is that they can use either values ​​(numbers, text, array etc.) or parameters of data sources.

Working with values

One possibility (rarely encountered) is to set parameters by values ​​(numbers, texts, arrays, etc.)

For example:

   await map.Geometric.Points.Appearance(e => e.type == "Industrial").SetStyle(new PieChart()
     {
         dimension = 40,

         title = "Park",
         visibilityZoomLevels = new VisibilityZoomLevels() { minZoomLevel = 8, maxZoomLevel = 10 },
         expandedIndex = 0,
         fontSize = 8,
         paramOrValues = new double[4] { 400, 200, 300, 50 },
         paramOrLabels = new string[3] { "Low", "Medium", "High" },
         paramOrColors = new string[4] { "white", "yellow", "red", "gray" }
     });

Working with parameters

As mentioned, the input data parameterization for Chart is based on template literals/template strings. In JavaScript the definition of a template literal is given by the following rules: 1. using backtick () characters to delimit the string 2. the parameter is passed using the${parameter}` convention

However, being an implementation made in C#, the first rule is excluded, and the string delimitation will be done with ":

`${parameter}` becomes "${parameter}"

For example:

   await map.Geometric.Points.Appearance(e => e.type == "Industrial").SetStyle(new PieChart()
     {
         dimension = 40,

         title = "Park",
         visibilityZoomLevels = new VisibilityZoomLevels() { minZoomLevel = 8, maxZoomLevel = 10 },
         expandedIndex = 0,
         fontSize = 8,
         paramOrValues = "${production}",
         paramOrLabels = "${texts}",
         paramOrColors = "${classes}"
     });

Where:

public List<StreamPoint> streamPoints = new List<StreamPoint>()
 {
            new StreamPoint()
            {
                coordinates = new Coordinates()
                {
                    xy = new double[2] { 50.860847591747186,  4.227255449993002 }
                },
                guid = new Guid("00000000-0000-0000-0000-000000000001"),
                type = "Industrial",
                value = new IndustrialValues()
                {
                    production = new double[4] { 400, 200, 300, 50 },
                    texts = new string[3] { "Low", "Medium", "High" },
                    classes = new string[4] { "white", "yellow", "red", "gray" }
                }

            }
}

and the IndustrialValues class is a custom class (user-defined):

In this example, the custom class is:

 public class  IndustrialValues
 {
     public double[]? production { get; set; }
     public string[]? texts { get; set; }
     public string[]? classes { get; set; }
 }