Defines a script expression that can be used to compute values. Depending on the context, the script may refer to external data which will be available when the expression is being evaluated.
Referenced by: Aggregate Field, Device Location Geotrigger Feed, Dictionary Renderer, Geotrigger Notification Options, Knowledge Graph Sub Table (KnowledgeGraphSubTable), KnowledgeGraph Sub Layer (KnowledgeGraphSubLayer), labelAngleInfo, Link Chart Aggregation Layer (LinkChartAggregationLayer), Link Chart Sub Layer (LinkChartSubLayer)
Properties
| Property | Details |
|---|---|
| expression | Optional expression in the Arcade expression language. If no expression is provided, then the default empty expression produces a null, empty string, zero or false when evaluated (depending on usage and context). |
| returnType | Optional return type of the Arcade expression. Defaults to string value. Number values are assumed to be double. This can be determined by the authoring client by executing the expression using a sample feature, although it can be corrected by the user. Knowing the returnType allows the authoring client to present fields in relevant contexts. For example, numeric fields in numeric contexts such as charts.Valid values:
|
| title | Optional title of the expression. Typically used when presenting the expression to end-users e.g. in dialogs, table-of-contents or editing tools. |
Scaling expression info Example
{
"title": "Scaling expression",
"expression": "$feature.size * 1.5",
"returnType": "number"
}Field lookup expression info Example
{
"title": "Population (Expr)",
"expression": "$feature.pop2000",
"returnType": "number"
}Concatenation expression info Example
{
"title": "Name (Abbr) (Expr)",
"expression": "$feature.state_name + ' (' + $feature.state_abbr + ')'",
"returnType": "string"
}