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View Reference Arcade expressions in PopupTemplate sample in sandbox
Reference Arcade expressions in PopupTemplate

Description

This sample demonstrates how to display values returned from an Arcade expression in a PopupTemplate defined on a FeatureLayer. Arcade is useful for creating visualizations in a FeatureLayer based on a value calculated from an expression executed on the client. PopupTemplates can reference the same expressions used in renderers to effectively communicate the data-driven visualization.

In this sample, a layer representing U.S. counties is added to the map. Each feature contains attributes related to labor statistics in the county. The fields include the unemployment rate, population, and total employment. Arcade is used to calculate the labor force participation of each county.

Four arcade expressions are used in the app. Each Arcade expression must be referenced in the expressionInfos property of the PopupTemplate. The expressionInfos is an array of objects that assigns a name and a title to each expression.

The name property is used to reference the expression value in the popupTemplate's content. The name must be prefaced by expression/.

See the Popup profile of the Arcade expressions guide for more information.

Code

<!DOCTYPE html>
<html>
<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no"/>
<title>Arcade in Popup</title>

<link rel="stylesheet" href="https://js.arcgis.com/3.25/esri/css/esri.css">
<link rel="stylesheet" href="https://js.arcgis.com/3.25/dijit/themes/claro/claro.css">
<script src="https://js.arcgis.com/3.25/"></script>

<style>
  html, body, #viewDiv {
    height: 100%;
    width: 100%;
    margin: 0;
    padding: 0;
  }
  #info{
    top: 0px;
    right: 0px;
    position: absolute;
    z-index: 99;
    opacity: 0.9;
    background-color: white;
    padding: 0px 0px 0px 10px;
    max-width: 200px;
  }
</style>


<script type="text/plain" id="predominance-arcade">
  // Arcade expression that determines the predominant category
  // in each feature. In this case we want to know whether more people living in
  // a given county are participating in the labor force.


  // The fields from which to calculate predominance
  // The expression will return the alias of the predominant field

  var fields = [
    { value: $feature.NOT_LABORFORCE_16, alias: "NOT participating in the labor force" },
    { value: $feature.CIVLBFR_CY, alias: "participating in the labor force" }
  ];

  // Returns the predominant category as the alias
  // defined in the fields array. If there is a tie,
  // then both names are concatenated and used to
  // indicate the tie

  function getPredominantCategory(fieldsArray){
    var maxValue = -Infinity;
    var maxCategory = "";
    for(var k in fieldsArray){
      if(fieldsArray[k].value > maxValue){
        maxValue = fieldsArray[k].value;
        maxCategory = fieldsArray[k].alias;
      } else if (fieldsArray[k].value == maxValue){
        maxCategory = maxCategory + "/" + fieldsArray[k].alias;
      }
    }
    return maxCategory;
  }

  getPredominantCategory(fields);
</script>

<script type="text/plain" id="strength-arcade">
  // Arcade expression determining the strength of the predominant count
  // in each feature based on the proportion of that count to all others.
  // A simple percentage is calculated and returned for the max value.

  // Returns the share of the dominant demographic as a percentage
  var fieldValues = [ $feature.NOT_LABORFORCE_16, $feature.CIVLBFR_CY ];
  var winner = Max(fieldValues);
  var total = Sum(fieldValues);
  return (winner/total) * 100;
</script>

<script>
require([
  "esri/map",
  "esri/layers/FeatureLayer",
  "esri/renderers/UniqueValueRenderer",
  "esri/symbols/SimpleMarkerSymbol",
  "esri/symbols/SimpleLineSymbol",
  "esri/Color",
  "esri/dijit/Legend",
  "esri/dijit/PopupTemplate",
  "dojo/domReady!"
], function(
  Map, FeatureLayer, UniqueValueRenderer, SimpleMarkerSymbol,
  SimpleLineSymbol, Color, Legend, PopupTemplate
) {

  // The expressionInfos reference Arcade expressions and
  // assign each of them a title and name. The name is used
  // to reference it in the PopupTemplate and the title is
  // used to describe the value in the popup and legend.

  var arcadeExpressionInfos = [
    // Get Arcade expression returning the predominant demographic in the county:
    // Whether the majority of people are in the labor force or not
    {
      name: "predominance-arcade",
      title: "Is the majority (>50%) of the population 16+ participating in the labor force?",
      expression: document.getElementById("predominance-arcade").text
    },
    // Get Arcade expression returning the share of the total comprised
    // by the predominant category
    {
      name: "strength-arcade",
      title: "% of population belonging to majority category",
      expression: document.getElementById("strength-arcade").text
    },
    // Arcade expression that returns the total number of people not working
    {
      name: "not-working-arcade",
      title: "Total population 16+ not employed or in labor force",
      expression: "$feature.POP_16UP - $feature.EMP_CY"
    },
    // Arcade expression that returns the % of people not working
    {
      name: "%-not-working-arcade",
      title: "% of population 16+ not employed or in labor force",
      expression: "Round((($feature.POP_16UP - $feature.EMP_CY)/$feature.POP_16UP)*100) + '%'"
    }
  ];

  // Add the expressions to a unique value renderer and create a
  // symbol for each possible value.

  var renderer = new UniqueValueRenderer({
    valueExpression: arcadeExpressionInfos[0].expression,
    valueExpressionTitle: arcadeExpressionInfos[0].title,
    defaultSymbol: createSymbol("lightgray"),
    defaultLabel: "Other/or tie",
    uniqueValueInfos: [{
      value: "participating in the labor force",
      symbol: createSymbol("#6b4da2")
    }, {
      value: "NOT participating in the labor force",
      symbol: createSymbol("#e86b0c")
    }],
    // Add an Arcade expression to an opacity visual variable. Counties where
    // the predominant category is nearly equal with the others (54%) are very
    // transparent. Counties where the predominant category makes up at least 66%
    // of all people 16 and older are fully opaque.
    visualVariables: [{
      type: "opacityInfo",
      valueExpression: arcadeExpressionInfos[1].expression,
      valueExpressionTitle: arcadeExpressionInfos[1].title,
      stops: [
        { value: 54, opacity: 0.05, label: "< 54%" },
        { value: 66, opacity: 1.0, label: "> 66%" }
      ]
    }, {
      type: "sizeInfo",
      field: "UNEMPRT_CY",
      minDataValue: 5,
      maxDataValue: 28.8,
      minSize: 6,
      maxSize: 50
    }]
  });

  // Create FeatureLayer instance with popupTemplate
  // Note the Arcade expression placeholders used in the text and fieldInfos
  // e.g. {expression/predominance-arcade}
  // Expression names are defined in the expressionInfos property

  var serviceUrl = "https://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/US_counties_employment_2016/FeatureServer/0";

  var layer = new FeatureLayer(serviceUrl, {
    outFields: [ "CIVLBFR_CY", "NOT_LABORFORCE_16", "COUNTY", "STATE", "POP_16UP", "UNEMPRT_CY", "UNEMP_CY", "EMP_CY" ],
    infoTemplate: new PopupTemplate({
      title: "{COUNTY}, {STATE}",
      description: [ "In this county, {UNEMPRT_CY}% of the labor force is unemployed. ",
        " {expression/strength-arcade}% of the {POP_16UP} people ages 16+",
        " living here are {expression/predominance-arcade}.<br><br>",
        "<b>Pop in labor force (16+):</b> {CIVLBFR_CY}<br>",
        "<b>Employed Pop:</b> {EMP_CY}<br>",
        "<b>Unemployed Pop:</b> {UNEMP_CY}<br>",
        "<b>Pop 16+ not working:</b> {expression/not-working-arcade}<br>",
        "<b>% of Pop 16+ not working:</b> {expression/%-not-working-arcade}<br>" ].join(""),
      fieldInfos: [{
        fieldName: "CIVLBFR_CY",
        label: "Population in labor force (16+)",
        format: {
          digitSeparator: true,
          places: 0
        }
      },  {
        fieldName: "EMP_CY",
        label: "Employed population",
        format: {
          digitSeparator: true,
          places: 0
        }
      }, {
        fieldName: "UNEMP_CY",
        label: "Unemployed population",
        format: {
          digitSeparator: true,
          places: 0
        }
      }, {
        fieldName: "expression/not-working-arcade",
        format: {
          digitSeparator: true,
          places: 0
        }
      }, {
        fieldName: "expression/%-not-working-arcade",
        format: {
          digitSeparator: true,
          places: 0
        }
      }, {
        fieldName: "POP_16UP",
        format: {
          digitSeparator: true,
          places: 0
        }
      }, {
        fieldName: "expression/strength-arcade",
        format: {
          digitSeparator: true,
          places: 0
        }
      }],
      expressionInfos: arcadeExpressionInfos
    })
  });

  layer.setRenderer(renderer);

  var map = new Map("viewDiv", {
    basemap: "gray",
    center: [ -83.5742, 35.05197 ],
    zoom: 6
  });

  map.addLayer(layer);

  // Create a legend when the map loads

  map.on("load", function(evt){
    var legend = new Legend({
      map: map,
      layerInfos: [{
        layer: layer,
        title: "Labor force statistics by U.S. county (2016)"
      }]
    }, "legendDiv");

    legend.startup();
  });

  // Creates a SimpleMarkerSymbol based on an input color

  function createSymbol (color){
    var outline = new SimpleLineSymbol()
      .setColor(new Color([ 0, 0, 0, 0.2 ]))
      .setWidth(0.5);

    return new SimpleMarkerSymbol()
      .setColor(new Color(color))
      .setOutline(outline);
  }

});
</script>
</head>

<body class="claro">
  <div id="viewDiv"></div>
  <div id="info"><div id="legendDiv"></div></div>
</body>

</html> 
          
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