The transparencyInfo visual variable defines the transparency, or opacity, of each feature's symbol based on a numeric attribute field value.
Referenced by: visualVariable
Properties
| Property | Details |
|---|---|
| field | Attribute field used for setting the transparency of a feature if no valueExpression is provided. |
| legendOptions | Options available for the legend. |
| normalizationField | Attribute field used to normalize the data. |
| stops[] | An array of transparencyStop objects. |
| type | Specifies the type of visual variable. Valid value of this property transparencyInfo |
| valueExpression | An Arcade expression evaluating to a number. |
| valueExpressionTitle | The title identifying and describing the associated Arcade expression as defined in the valueExpression property. |
Example
Live sample web maps showing use of the transparencyInfo visual variable.
{
"type": "transparencyInfo",
"valueExpression": "var fieldNames = [ \"GRADDEG_CY\", \"BACHDEG_CY\", \"SMCOLL_CY\", \"HSGRAD_CY\" ];\nvar numFields = 4;\nvar maxValueField = null;\nvar maxValue = -Infinity;\nvar value, i, totalValue = null;\nfor(i = 0; i < numFields; i++) {\nvalue = $feature[fieldNames[i]];\nif(value > 0) {\nif(value > maxValue) {\nmaxValue = value;\nmaxValueField = fieldNames[i];\n}\nelse if (value == maxValue) {\nmaxValueField = null;\n}\n}\nif(value != null && value >= 0) {\nif (totalValue == null) { totalValue = 0; }\ntotalValue = totalValue + value;\n}\n}\nvar strength = null;\nif (maxValueField != null && totalValue > 0) {\nstrength = (maxValue / totalValue) * 100;\n}\nreturn strength;",
"stops": [
{
"value": 25,
"transparency": 85
},
{
"value": 50,
"transparency": 0
}
],
"legendOptions": {
"title": "Strength of predominance"
}
}