Object management in Kontrast

Creating objects

In Kontrast, objects are created according to the hierarchy listed below. All objects are ultimately the child of the global kontrast object.

• kontrast
  • Slider
  • Figure
    • Graph
      • Axis
        • Abscissa
        • Ordinate
        • Applicate
        • Color axis
        • Opacity axis
        • Thickness axis
      • Plot
        • Points
        • Lines
        • Bars
        • Pixels
        • Tiles
        • Cubes
        • Cursor
      • Annotation

There are two ways to create objects in Kontrast:

1. You can call the function createX, where X is Figure, Graph, Points, Lines, …

   The createX function needs to be called on the parent object. For example, to create a graph inside a figure, you can call figure.createGraph({ … }):

   let figure = kontrast.createFigure() figure.createGraph({ name: 'upperGraph', aspectRatio: 1 })

2. You can include an object inside an initializer property. The following code achieves the same result as the snippet above:

   kontrast.createFigure({ graphs: { upperGraph: { aspectRatio: 1 } } })

   Note that the name property (name: 'upperGraph') is automatically assigned when using the initializer property.

A more elaborate example is the basic setup of a figure with a single graph that contains an abscissa, an ordinate and a point plot.

Accessing child objects

You can access all child objects that belong to a certain parent object by accessing the corresponding collection. For example, each figure has a property named graphs. A collection property is simply a JavaScript object, i.e. a list of key–value pairs. The key is the child object name, the corresponding value is the child object.

The following code snippet iterates over all graphs of a figure. It prints a list of their names and their aspect ratio to the console:

The following code snippet colors all line plots blue.