Class ArcadeEvaluator

Allows you to evaluate an ArcadeExpression under a given ArcadeProfile.

Inheritance

System.Object

ArcadeEvaluator

Implements

ILoadable

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: Esri.ArcGISRuntime.Arcade

Assembly: Esri.ArcGISRuntime.dll

Syntax

public sealed class ArcadeEvaluator : ILoadable

Remarks

This object allows you to set up, execute and query information about an Arcade script. For more general information on Arcade and its usages we refer you to the Arcade online documentation.

To construct the ArcadeEvaluator object you need to supply an ArcadeExpression along with an ArcadeProfile. ArcadeExpression is an object that contains the Arcade script plus some additional metadata while ArcadeProfile specifies availability of profile variables and limits what functions are available.

The basic workflow is:

• Construct an ArcadeEvaluator object using ArcadeExpression and ArcadeProfile.
• Query information about a script.
• Insert the required profile values into a dictionary.
• Call EvaluateAsync(IEnumerable<KeyValuePair<String, Object>>).
• Use the returned ArcadeEvaluationResult.

From an ArcadeEvaluator object you can query information to determine:

• Which profile variables are accessed by the script.
• Which attributes are used by a particular profile variable.
• If the script is considered stable.

Not all scripts use all the profiles variables. ProfileVariablesUsed returns an array of the names of the profile variables used in the current script. Possible uses include:

• Informing dependency analysis to determine which scripts need to run when a value of a profile variable changes.
• Minimizing expensive calculation of unneeded profile variables.

GetAttributesAsync(String, FeatureTable) lets you dig deeper to determine which attributes are required on a specific profile variable. If you are querying a subset of attributes when querying a feature, use this information to ensure the profile variable will have the attributes it requires.

IsStable property indicates if the given script will return the same value for an identical set of profile variables. For this to be true a script must avoid using unstable builtin functions such as now() or random().

IsStable can be combined with the knowledge of the used profile variables to construct caches of results. This lets you avoid running scripts when repeated calls with the same profiles variables will not alter the evaluation result.

Constructors

Name	Description
ArcadeEvaluator(ArcadeExpression, ArcadeProfile)	Initializes a new instance of the ArcadeEvaluator class with the specified expression and profile.

Properties

Name	Description
IsStable	Gets a value indicating whether the script is considered stable.
LoadError	Gets the System.Exception associated with the last load error.
LoadStatus	Gets the load status.
Profile	Gets the Arcade profile under which the script should evaluate.
ProfileVariablesUsed	Gets a collection containing the names of all profile variables used in the script.

Methods

Name	Description
CancelLoad()	Cancel loading metadata for the object.
CreateAsync(ArcadeExpression, ArcadeProfile)	Creates a new instance of the ArcadeEvaluator class with the specified Arcade expression and execution context.
EvaluateAsync(IEnumerable<KeyValuePair<String, Object>>)	Evaluates the script using the supplied profile variables.
GetAttributesAsync(String, FeatureTable)	Returns a collection of attributes used in the script for a given profile variable.
GetAttributesAsync(String, GeoElement)	Returns a collection of attributes used in the script for a given profile variable.
LoadAsync()	Load the metadata for the object asynchronously.
RetryLoadAsync()	Loads or retries loading metadata for the object asynchronously.

Events

Name	Description
Loaded	Occurs when the Arcade evaluator is loaded.
LoadStatusChanged	Occurs when the LoadStatus property is changed.

Applies to

Target	Versions
.NET Standard 2.0	100.14 - 200.6
.NET	100.14 - 200.6
.NET Windows	100.14 - 200.6
.NET Android	200.0 - 200.6
.NET iOS	200.0 - 200.6
.NET Framework	100.14 - 200.6
Xamarin.Android	100.14 - 100.15
Xamarin.iOS	100.14 - 100.15
UWP	100.14 - 200.6