The Representation Object

The representation object defines the relation between the requested data and the representation type, for example, a particular chart type or a list. The format is as follows:

{
  "type" : "representation",    // optional
  "id" : "<id>"
  "representationTypeId" : "<representation type ID>",
  "parameter" : {
    "type" : "parameter"
    "dimensions" : [ <dimensions>* ]
    "measures" : [ <measures><representation type ID>"    // optional
    "width" : * ]
    "alternateRepresentationType" : "<width>        //optional
    "top" : "<number>"       //optional
    "orderby" : [ <orderby>* ]             //optional
            }
}

The properties used in the representation object denote the following:

Property	Description
id	Unique ID of type string.
representationTypeId	ID of the representation type
parameter	Defines specific information for the representation, for example, dimensions, measures, the optional alternate representation, and the column width for table representations. At runtime, the constructor defined in the object, which contains a label, an image, and a reference to the constructor function of the representation type.representation type object is called with the parameters defined by this property.

Dimensions and Measures

The parameter property can contain dimensions and measures for the representation.

The dimensions property has the following format:

*  object, which contains a"dimensions" : [
    {
        "fieldName" : "<field name>",
        "kind" : "<value>",
        "fieldDesc" : {
            "type" : "label",
            "kind" : "text",
            "key" : "<key>"
        }
    }
]

The kind attribute provides the option to maintain multiple dimensions.

If you use VizFrame charts, the kind attribute is mapped to feedItemId. The following table lists the feedItemId for the available charts:

Chart Type	Dimension	feedItemId
Line chart, line chart with two vertical axes, column chart, bar chart, stacked column chart, stacked bar chart, percentage stacked column chart, percentage stacked bar chart	First dimension	categoryAxis
	Second dimension	color
Line chart with time axis	First dimension	timeAxis
Line chart with time axis	Second dimension	color
Heatmap chart	First dimension	categoryAxis
Heatmap chart	Second dimension	valueAxis
Pie chart	Dimension	color
Scatter chart	First dimension	color
Scatter chart	Second dimension	shape
Bubble chart	First dimension	color
Bubble chart	Second dimension	shape

If you use VIZ charts, supported values for the different chart types are:

Representation Type	Values
Column chart	xAxis, legend
Stacked column chart	xAxis, legend
Percentage stacked column chart	xAxis, legend
Line chart	xAxis, legend
Pie chart	sectorColor
Bubble chart	regionColor, regionShape
Scatter plot chart	regionColor, regionShape

The measures property has the following format:

"measures" : [
    {
        "fieldName" : "<field name>",
        "kind" : "<value>",
        "fieldDesc" : {
            "type" : "label",
            "kind" : "text",
            "key" : "<key>"
        }
    }
]

The kind attribute provides the option to maintain multiple measures.

If you use VizFrame charts, the kind attribute is mapped to feedItemId. The following table lists the feedItemId for the available charts:

Chart Type	Measure	feedItemId
Line chart, line chart with time axis, column chart, bar chart, stacked column chart, stacked bar chart, percentage stacked column chart, percentage stacked bar chart	Measure	valueAxis
Heatmap chart	Measure	Color
Pie chart	Measure	size
Scatter chart, line chart with two vertical axes	First measure	valueAxis
Scatter chart, line chart with two vertical axes	Second measure	valueAxis2
Bubble chart	First measure	valueAxis
	Second measure	valueAxis2
	Third measure	bubbleWidth

If you use VIZ charts, supported values for the different representation types are:

Representation Type	Values
Column chart	yAxis
Stacked column chart	yAxis
Percentage stacked column chart	yAxis
Line chart	yAxis
Pie chart	sectorSize
Bubble chart	xAxis, yAxis, bubbleWidth
Scatter plot chart	xAxis, yAxis, bubbleWidth, bubbleHeight

The optional fieldDesc property of the dimensions and measures properties can be used for rendering the axis titles in the chart. For more information, see Rendering of Charts.

Alternate Representation

For each representation, you can define an alternate representation. A user can switch to the alternate representation directly from any representation without having to access the gallery of available representation types.

To define an alternate representation, the configuration file must contain the following parameter:

"alternateRepresentationType" : "<representationTypeId>"

The property alternateRepresentationType contains a reference to the representation type ID that is configured with details such as the constructor. The constructor of an alternate representation type is handed over to the representation instance using the parameter object.

Ordering

Using the orderby property, you can define the properties by which the data depicted in the representation is ordered. You can also specify the ordering direction (true = ascending, false = descending).

The orderby property has the following format:

"orderby" : [{             //optional
        "property" : "<property name>",
        "ascending" : <boolean>
        }*]