layout: default title: FieldElement parent: Core Classes —
dymaptic.GeoBlazor.Core
dymaptic.GeoBlazor.Core.Components.Widgets
FieldElement Class
A FieldElement form element defines how a feature layer’s field participates in the FeatureForm. This is the recommended approach to set field configurations within a feature form’s or feature layer’s formTemplate.
ArcGIS Maps SDK for JavaScript
public class FieldElement : dymaptic.GeoBlazor.Core.Components.Widgets.FormElement
Inheritance System.Object 🡒 Microsoft.AspNetCore.Components.ComponentBase 🡒 MapComponent 🡒 FormElement 🡒 FieldElement
Constructors
FieldElement() Constructor
Parameterless constructor for use as a razor component
public FieldElement();
FieldElement(string, string, string, string, string, string, string, Domain, FormInput) Constructor
Creates a new FieldElement in code with parameters
public FieldElement(string? fieldName, string? label=null, string? description=null, string? hint=null, string? editableExpression=null, string? requiredExpression=null, string? valueExpression=null, dymaptic.GeoBlazor.Core.Components.Widgets.Domain? domain=null, dymaptic.GeoBlazor.Core.Components.Widgets.FormInput? input=null);
Parameters
fieldName System.String
The field name as defined by the feature layer. Set this property to indicate which field to edit.
label System.String
The string template for defining how to format the title displayed at the top of a form.
description System.String
The description of the form.
hint System.String
Contains a hint used to help editors while editing fields. Set this as a temporary placeholder for text/number inputs in either TextAreaInput or TextBoxInput.
editableExpression System.String
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Constraint Profile. Expressions may reference field values using the $feature global input and must return either true or false.
requiredExpression System.String
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Constraint Profile. Expressions may reference field values using the $feature global input and must return either true or false.
valueExpression System.String
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Calculation Profile. This expression references field values within an individual feature or in other layers and must return either a date, number, or string value.
domain Domain
The coded value domain or range domain of the field.
input FormInput
The input to use for the element. The client application is responsible for defining the default user interface.
Properties
FieldElement.Domain Property
The coded value domain or range domain of the field.
public dymaptic.GeoBlazor.Core.Components.Widgets.Domain? Domain { get; set; }
Property Value
FieldElement.EditableExpression Property
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Constraint Profile. Expressions may reference field values using the $feature global input and must return either true or false.
public string? EditableExpression { get; set; }
Property Value
Remarks
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Constraint Profile. Expressions may reference field values using the $feature global input and must return either true or false.
The referenced expression must be defined in the form template’s expressionInfos. It cannot be set inline within the element object.
FieldElement.FieldName Property
The field name as defined by the feature layer. Set this property to indicate which field to edit.
public string? FieldName { get; set; }
Property Value
FieldElement.Hint Property
Contains a hint used to help editors while editing fields. Set this as a temporary placeholder for text/number inputs in either TextAreaInput or TextBoxInput.
public string? Hint { get; set; }
Property Value
FieldElement.Input Property
The input to use for the element. The client application is responsible for defining the default user interface.
public dymaptic.GeoBlazor.Core.Components.Widgets.FormInput? Input { get; set; }
Property Value
FieldElement.RequiredExpression Property
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Constraint Profile. Expressions may reference field values using the $feature global input and must return either true or false.
When this expression evaluates to true and the field value is required, the element must have a valid value in order for the feature to be created or edited. When the expression evaluates to false, the element is not required. If no expression is provided, the required behavior is defined via the required property.
If the referenced field is non-nullable, the requiredExpression is ignored and the element is always required.
public string? RequiredExpression { get; set; }
Property Value
Remarks
The referenced expression must be defined in the form template’s expressionInfos. It cannot be set inline within the element object.
FieldElement.Type Property
Indicates the type of form element.
public override string Type { get; }
Property Value
FieldElement.ValueExpression Property
A reference to the name of an Arcade expression defined in the expressionInfos of the FormTemplate. The expression must follow the specification defined in the Form Calculation Profile. This expression references field values within an individual feature or in other layers and must return either a date, number, or string value.
public string? ValueExpression { get; set; }
Property Value
Remarks
Once the expression evaluates, the form’s field value updates to the expressions’ result.
It is required to set the view property when instantiating a FeatureForm widget and using expressions that use the $map variable.
The referenced expression must be defined in the form template’s expressionInfos. It cannot be set inline within the element object.
Methods
FieldElement.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.
FieldElement.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.