layout: default title: VisualVariable parent: Core Classes —
dymaptic.GeoBlazor.Core
dymaptic.GeoBlazor.Core.Components.Layers
VisualVariable Class
The visual variable base class. See each of the subclasses that extend this class to learn how to create continuous
data-driven thematic visualizations.
ArcGIS Maps SDK for JavaScript
public abstract class VisualVariable : dymaptic.GeoBlazor.Core.Components.MapComponent
Inheritance System.Object 🡒 Microsoft.AspNetCore.Components.ComponentBase 🡒 MapComponent 🡒 VisualVariable
Derived
↳ ColorVariable
↳ OpacityVariable
↳ RotationVariable
↳ SizeVariable
Properties
VisualVariable.Field Property
The name of the numeric attribute field that contains the data values used to determine the
color/opacity/size/rotation of each feature.
public string Field { get; set; }
Property Value
VisualVariable.LegendOptions Property
An object providing options for displaying the visual variable in the Legend.
public dymaptic.GeoBlazor.Core.Components.Layers.LegendOptions? LegendOptions { get; set; }
Property Value
VisualVariable.ValueExpression Property
An Arcade expression following the specification defined by the Arcade Visualization Profile. Expressions in visual variables may reference field values using the $feature profile variable and must return a number.
The values returned from this expression are the data used to drive the visualization as defined in the stops. This takes precedence over field. Therefore, this property is typically used as an alternative to field in visual variables.
public string? ValueExpression { get; set; }
Property Value
VisualVariable.ValueExpressionTitle Property
The title identifying and describing the associated Arcade expression as defined in the valueExpression property. This is displayed as the title of the corresponding visual variable in the Legend in the absence of a provided title in the legendOptions property.
public string? ValueExpressionTitle { get; set; }
Property Value
VisualVariable.VariableType Property
The visual variable type.
public virtual dymaptic.GeoBlazor.Core.Components.Layers.VisualVariableType VariableType { get; }
Property Value
Methods
VisualVariable.RegisterChildComponent(MapComponent) Method
Called from dymaptic.GeoBlazor.Core.Components.MapComponent.OnInitializedAsync to “Register” the current component with it’s parent.
public override System.Threading.Tasks.Task RegisterChildComponent(dymaptic.GeoBlazor.Core.Components.MapComponent child);
Parameters
child MapComponent
The calling, child component to register
Returns
Exceptions
InvalidChildElementException
Throws if the current child is not a valid sub-component to the parent.
Remarks
This method is an implementation detail and should not be called directly by consumers. In future versions, this may be changed to an internal method. If you see no other way to register a child component, please open an issue on GitHub.
VisualVariable.UnregisterChildComponent(MapComponent) Method
Undoes the “Registration” of a child with its parent.
public override System.Threading.Tasks.Task UnregisterChildComponent(dymaptic.GeoBlazor.Core.Components.MapComponent child);
Parameters
child MapComponent
The child to unregister
Returns
Remarks
This method is an implementation detail and should not be called directly by consumers. In future versions, this may be changed to an internal method.