Mode d’emploi
- Copiez la commande et examinez le paquet avant de l’installer dans votre environnement agent.
- Consultez le document original pour les outils, identifiants et environnements requis.
- Décrivez les entrées et le livrable souhaité ; comparez la sortie aux sources.
npx skills add https://github.com/saschabrunnerch/arcgis-maps-sdk-js-ai-context --skill arcgis-arcadeAvant de commencer
- L’installation n’inclut ni abonnement au modèle, ni quota API, ni accès aux fichiers.
- Étoiles et installations reflètent l’activité, pas un test indépendant de qualité ou de sécurité.
Document Skill original
Rendu depuis le dépôt source en conservant titres, exemples, code, tableaux, liens et images.
ArcGIS Arcade Expressions
Use this skill for writing Arcade expressions for popups, renderers, labels, and calculations.
Import Patterns
Direct ESM Imports
javascript
import * as arcade from "@arcgis/core/arcade.js";Dynamic Imports (CDN)
javascript
const arcade = await $arcgis.import("@arcgis/core/arcade.js");Arcade Basics
Arcade is an expression language for ArcGIS. It's used for:
- Dynamic popup content
- Data-driven rendering
- Custom labels
- Field calculations
- Form validation
Basic Syntax
arcade
// Variables
var population = $feature.population;
var area = $feature.area_sqkm;
// Calculations
var density = population / area;
// Return result
return Round(density, 2);Arcade in PopupTemplates
Expression Infos
javascript
const popupTemplate = {
title: "{name}",
expressionInfos: [
{
name: "population-density",
title: "Population Density",
expression: "Round($feature.population / $feature.area_sqkm, 2)",
},
{
name: "formatted-date",
title: "Formatted Date",
expression: "Text($feature.created_date, 'MMMM D, YYYY')",
},
],
content: "Density: {expression/population-density} people/km²",
};Complex Expressions
javascript
const popupTemplate = {
title: "{name}",
expressionInfos: [
{
name: "predominant-category",
title: "Predominant Category",
expression: `
var fields = [
{ value: $feature.category_a, alias: "Category A" },
{ value: $feature.category_b, alias: "Category B" },
{ value: $feature.category_c, alias: "Category C" }
];
var maxValue = -Infinity;
var maxCategory = "";
for (var i in fields) {
if (fields[i].value > maxValue) {
maxValue = fields[i].value;
maxCategory = fields[i].alias;
}
}
return maxCategory;
`,
},
],
content: [
{
type: "text",
text: "The predominant category is: {expression/predominant-category}",
},
{
type: "fields",
fieldInfos: [
{
fieldName: "expression/predominant-category",
},
],
},
],
};Arcade in Renderers
Value Expression
javascript
const renderer = {
type: "unique-value",
valueExpression: `
var labor = $feature.labor_force;
var notLabor = $feature.not_in_labor_force;
if (labor > notLabor) {
return "In labor force";
} else {
return "Not in labor force";
}
`,
valueExpressionTitle: "Labor Force Status",
uniqueValueInfos: [
{
value: "In labor force",
symbol: { type: "simple-fill", color: "blue" },
},
{
value: "Not in labor force",
symbol: { type: "simple-fill", color: "orange" },
},
],
};Visual Variable Expression
javascript
const renderer = {
type: "simple",
symbol: { type: "simple-marker", color: "red" },
visualVariables: [
{
type: "size",
valueExpression: "Sqrt($feature.population) * 0.1",
valueExpressionTitle: "Population (scaled)",
stops: [
{ value: 10, size: 4 },
{ value: 100, size: 40 },
],
},
{
type: "opacity",
valueExpression: "($feature.value / $feature.max_value) * 100",
valueExpressionTitle: "Percentage of max",
stops: [
{ value: 20, opacity: 0.2 },
{ value: 80, opacity: 1 },
],
},
],
};Arcade in Labels
javascript
layer.labelingInfo = [
{
symbol: {
type: "text",
color: "black",
font: { size: 10 },
},
labelExpressionInfo: {
expression: `
var name = $feature.name;
var pop = $feature.population;
if (pop > 1000000) {
return name + " (" + Round(pop/1000000, 1) + "M)";
} else if (pop > 1000) {
return name + " (" + Round(pop/1000, 0) + "K)";
}
return name;
`,
},
where: "population > 50000",
},
];Common Arcade Functions
Math Functions
arcade
Round(3.14159, 2) // 3.14
Floor(3.9) // 3
Ceil(3.1) // 4
Abs(-5) // 5
Sqrt(16) // 4
Pow(2, 3) // 8
Min(1, 2, 3) // 1
Max(1, 2, 3) // 3
Sum([1, 2, 3]) // 6
Mean([1, 2, 3]) // 2Text Functions
arcade
Upper("hello") // "HELLO"
Lower("HELLO") // "hello"
Trim(" hello ") // "hello"
Left("hello", 2) // "he"
Right("hello", 2) // "lo"
Mid("hello", 2, 2) // "ll"
Find("l", "hello") // 2
Replace("hello", "l", "L") // "heLLo"
Split("a,b,c", ",") // ["a", "b", "c"]
Concatenate(["a", "b"]) // "ab"Date Functions
arcade
Now() // Current date/time
Today() // Current date
Year($feature.date_field) // Extract year
Month($feature.date_field) // Extract month (1-12)
Day($feature.date_field) // Extract day
DateDiff(Now(), $feature.date, "days") // Days between dates
Text($feature.date, "MMMM D, YYYY") // Format dateGeometry Functions
arcade
Area($feature, "square-kilometers")
Length($feature, "kilometers")
Centroid($feature)
Buffer($feature, 100, "meters")
Intersects($feature, $otherFeature)
Contains($feature, $point)Conditional Functions
arcade
// IIf (inline if)
IIf($feature.value > 100, "High", "Low")
// When (multiple conditions)
When(
$feature.type == "A", "Type A",
$feature.type == "B", "Type B",
"Other"
)
// Decode (value matching)
Decode($feature.code,
1, "One",
2, "Two",
3, "Three",
"Unknown"
)Array Functions
arcade
var arr = [1, 2, 3, 4, 5];
Count(arr) // 5
First(arr) // 1
Last(arr) // 5
IndexOf(arr, 3) // 2
Includes(arr, 3) // true
Push(arr, 6) // [1, 2, 3, 4, 5, 6]
Reverse(arr) // [5, 4, 3, 2, 1]
Sort(arr) // [1, 2, 3, 4, 5]
Slice(arr, 1, 3) // [2, 3]Feature Access
arcade
// Current feature
$feature.fieldName
// All features in layer (for aggregation)
var allFeatures = FeatureSet($layer);
var filtered = Filter(allFeatures, "type = 'A'");
var total = Sum(filtered, "value");
// Related records
var related = FeatureSetByRelationshipName($feature, "relationshipName");
// Global variables
$map // Reference to map
$view // Reference to view
$datastore // Reference to data storeExecute Arcade Programmatically
javascript
import * as arcade from "@arcgis/core/arcade.js";
// Create profile
const profile = {
variables: [
{
name: "$feature",
type: "feature",
},
],
};
// Compile expression
const executor = await arcade.createArcadeExecutor(
"Round($feature.value * 100, 2)",
profile,
);
// Execute with feature
const result = await executor.executeAsync({
$feature: graphic,
});
console.log("Result:", result);Note: In v5.0,ExecuteContext.lruCacheis deprecated. UseExecuteContext.cacheinstead.
Arcade in HTML (Script Tags)
html
<script type="text/plain" id="my-expression">
var total = $feature.value_a + $feature.value_b;
var percentage = Round((total / $feature.max_value) * 100, 1);
return percentage + "%";
</script>
<script type="module">
const expression = document.getElementById("my-expression").text;
const popupTemplate = {
expressionInfos: [
{
name: "my-calc",
expression: expression,
},
],
content: "Value: {expression/my-calc}",
};
</script>Arcade Expression Profiles
Different Arcade profiles expose different global variables and functions:
| Profile | Global Variables | Used For |
|---|---|---|
popup | $feature, $layer, $map, $datastore | Popup content |
visualization | $feature, $view | Renderers, visual variables |
labeling | $feature, $view | Label expressions |
field-calculate | $feature, $layer | Field calculations |
form-calculation | $feature, $layer, $originalFeature | Form calculated expressions |
constraint | $feature, $layer, $originalFeature | Form validation |
alias | $feature, $layer | Cluster popup aliases |
Reference Samples
popuptemplate-arcade- Arcade expressions in PopupTemplatespopuptemplate-arcade-expression-content- Arcade expression content in popupsvisualization-arcade- Arcade-driven visualizationarcade-execute-chart- Execute Arcade with charting
Common Pitfalls
- Null values: Always check for nulls with
IsEmpty($feature.field)before arithmetic operations. Dividing by null or adding to null produces null.
arcade
// Anti-pattern: no null check
return $feature.population / $feature.area;arcade
// Correct: check for null
if (IsEmpty($feature.area) || $feature.area == 0) {
return "N/A";
}
return Round($feature.population / $feature.area, 2);- Type coercion: Use
Number()orText()for explicit conversion when mixing types.
- Case sensitivity: Arcade function names are case-insensitive, but field names must match the source data exactly.
- Performance: Complex expressions in renderers and labels evaluate per feature per frame. Keep them simple for large datasets.
- Debugging: Use the
Console()function to debug expressions. Output appears in the browser's developer console.
- FeatureSet queries:
FeatureSet()andFilter()execute server-side queries. They can be slow in popup expressions if the layer has many features.
Related Skills
- See
arcgis-popup-templatesfor popup template configuration - See
arcgis-visualizationfor renderer and symbol configuration - See
arcgis-smart-mappingfor data-driven visualization - See
arcgis-coding-componentsfor the<arcgis-arcade-editor>component
