ArcGIS Widgets & UI

Use this skill when building user interfaces with widgets, Map Components, and Calcite.

Best Practice: Prefer Map Components (web components like arcgis-legend, arcgis-search) over Core API widgets. Esri has transitioned to web components as the primary approach.

Import Patterns

Map Components (ESM)

import "@arcgis/map-components/dist/components/arcgis-map";
import "@arcgis/map-components/dist/components/arcgis-legend";
import "@arcgis/map-components/dist/components/arcgis-search";
import "@arcgis/map-components/dist/components/arcgis-layer-list";
import "@arcgis/map-components/dist/components/arcgis-expand";

Core API Widgets (ESM)

import Legend from "@arcgis/core/widgets/Legend.js";
import LayerList from "@arcgis/core/widgets/LayerList.js";
import Search from "@arcgis/core/widgets/Search.js";
import BasemapGallery from "@arcgis/core/widgets/BasemapGallery.js";

Dynamic Imports (CDN)

const Legend = await $arcgis.import("@arcgis/core/widgets/Legend.js");
const Search = await $arcgis.import("@arcgis/core/widgets/Search.js");

Note: CSS for Map Components loads automatically via npm. Core API widgets require: @import "@arcgis/core/assets/esri/themes/light/main.css";

Map Components Overview

Slot-Based Positioning

<arcgis-map basemap="streets-vector">
  <!-- Position widgets using slots -->
  <arcgis-zoom slot="top-left"></arcgis-zoom>
  <arcgis-home slot="top-left"></arcgis-home>
  <arcgis-compass slot="top-left"></arcgis-compass>

  <arcgis-search slot="top-right"></arcgis-search>
  <arcgis-layer-list slot="top-right"></arcgis-layer-list>

  <arcgis-legend slot="bottom-left"></arcgis-legend>
  <arcgis-scale-bar slot="bottom-right"></arcgis-scale-bar>

  <!-- Popup must use popup slot -->
  <arcgis-popup slot="popup"></arcgis-popup>
</arcgis-map>

Available slots: top-left, top-right, bottom-left, bottom-right, top-start, top-end, bottom-start, bottom-end, popup

Widgets in the same slot stack vertically in DOM order.

Expand Component

Wrap widgets in arcgis-expand for collapsible behavior:

<arcgis-map basemap="streets-vector">
  <arcgis-expand slot="top-right" expand-tooltip="Show Legend" mode="floating">
    <arcgis-legend></arcgis-legend>
  </arcgis-expand>

  <arcgis-expand slot="top-left" expanded>
    <arcgis-layer-list></arcgis-layer-list>
  </arcgis-expand>
</arcgis-map>

Reference Element (External Components)

Place components outside the map and reference them:

<calcite-shell>
  <calcite-shell-panel slot="panel-start">
    <arcgis-legend reference-element="arcgis-map"></arcgis-legend>
  </calcite-shell-panel>

  <arcgis-map id="arcgis-map" basemap="topo-vector">
    <arcgis-zoom slot="top-left"></arcgis-zoom>
  </arcgis-map>
</calcite-shell>

Common Widgets

Legend

<!-- Map Component -->
<arcgis-legend slot="bottom-left"></arcgis-legend>

// Core API
import Legend from "@arcgis/core/widgets/Legend.js";

const legend = new Legend({
  view: view,
  layerInfos: [
    {
      layer: featureLayer,
      title: "Custom Title",
    },
  ],
});

view.ui.add(legend, "bottom-left");

LayerList

<!-- Map Component -->
<arcgis-layer-list slot="top-right"></arcgis-layer-list>

// Core API with actions
import LayerList from "@arcgis/core/widgets/LayerList.js";

const layerList = new LayerList({
  view: view,
  listItemCreatedFunction: (event) => {
    const item = event.item;
    item.actionsSections = [
      [
        {
          title: "Zoom to layer",
          icon: "zoom-to-object",
          id: "zoom-to",
        },
      ],
    ];
  },
});

layerList.on("trigger-action", (event) => {
  if (event.action.id === "zoom-to") {
    view.goTo(event.item.layer.fullExtent);
  }
});

view.ui.add(layerList, "top-right");

BasemapGallery

<!-- Map Component -->
<arcgis-basemap-gallery slot="top-right"></arcgis-basemap-gallery>

// Core API
import BasemapGallery from "@arcgis/core/widgets/BasemapGallery.js";

const basemapGallery = new BasemapGallery({ view: view });
view.ui.add(basemapGallery, "top-right");

Search

<!-- Map Component -->
<arcgis-search slot="top-right"></arcgis-search>

// Core API with custom sources
import Search from "@arcgis/core/widgets/Search.js";

const search = new Search({
  view: view,
  sources: [
    {
      layer: featureLayer,
      searchFields: ["name", "address"],
      displayField: "name",
      exactMatch: false,
      outFields: ["*"],
      name: "My Layer",
      placeholder: "Search features",
    },
  ],
});

view.ui.add(search, "top-right");

// Events
search.on("select-result", (event) => {
  console.log("Selected:", event.result);
});

FeatureTable

<!-- Map Component -->
<arcgis-feature-table reference-element="arcgis-map"></arcgis-feature-table>

// Core API
import FeatureTable from "@arcgis/core/widgets/FeatureTable.js";

const featureTable = new FeatureTable({
  view: view,
  layer: featureLayer,
  container: "tableDiv",
  visibleElements: {
    header: true,
    columnMenus: true,
    selectionColumn: true,
  },
  tableTemplate: {
    columnTemplates: [
      { fieldName: "name", label: "Name" },
      { fieldName: "population", label: "Population" },
    ],
  },
});

// Watch selection via highlightIds
featureTable.highlightIds.on("change", (event) => {
  console.log("Selected IDs:", featureTable.highlightIds.toArray());
});

TimeSlider

<!-- Map Component -->
<arcgis-time-slider
  slot="bottom-right"
  layout="auto"
  mode="time-window"
  time-visible
  loop
>
</arcgis-time-slider>

<script type="module">
  const timeSlider = document.querySelector("arcgis-time-slider");
  const mapEl = document.querySelector("arcgis-map");
  await mapEl.viewOnReady();

  await layer.load();
  timeSlider.fullTimeExtent = layer.timeInfo.fullTimeExtent;
  timeSlider.stops = { interval: layer.timeInfo.interval };
</script>

// Core API
import TimeSlider from "@arcgis/core/widgets/TimeSlider.js";

const timeSlider = new TimeSlider({
  view: view,
  mode: "time-window", // instant, time-window, cumulative-from-start, cumulative-from-end
  fullTimeExtent: layer.timeInfo.fullTimeExtent,
  stops: {
    interval: { value: 1, unit: "hours" },
  },
  playRate: 1000,
  loop: true,
});

view.ui.add(timeSlider, "bottom-right");

// Events
import * as reactiveUtils from "@arcgis/core/core/reactiveUtils.js";

reactiveUtils.watch(
  () => timeSlider.timeExtent,
  (timeExtent) => {
    console.log("Time changed:", timeExtent.start, timeExtent.end);
  },
);

Core Widget Approach

Adding Widgets to View

import Legend from "@arcgis/core/widgets/Legend.js";

const legend = new Legend({ view: view });

// Add to view UI
view.ui.add(legend, "bottom-left");

// Add multiple widgets
view.ui.add([
  { component: legend, position: "bottom-left" },
  { component: search, position: "top-right" },
]);

// Add at specific index (order in position)
view.ui.add(legend, { position: "bottom-left", index: 0 });

// Remove widget
view.ui.remove(legend);

Widget in Custom Container

<div id="legendDiv"></div>

<script type="module">
  import Legend from "@arcgis/core/widgets/Legend.js";

  const legend = new Legend({
    view: view,
    container: "legendDiv",
  });
</script>

Calcite Design System Integration

Basic Layout with Calcite

<!DOCTYPE html>
<html>
  <head>
    <link
      rel="stylesheet"
      href="https://js.arcgis.com/5.0/@arcgis/core/assets/esri/themes/light/main.css"
    />
    <script src="https://js.arcgis.com/5.0/"></script>
    <script
      type="module"
      src="https://js.arcgis.com/map-components/5.0/arcgis-map-components.esm.js"
    ></script>
    <style>
      html,
      body {
        height: 100%;
        margin: 0;
      }
    </style>
  </head>
  <body class="calcite-mode-light">
    <calcite-shell>
      <!-- Header -->
      <calcite-navigation slot="header">
        <calcite-navigation-logo
          slot="logo"
          heading="My Map App"
        ></calcite-navigation-logo>
      </calcite-navigation>

      <!-- Side Panel -->
      <calcite-shell-panel slot="panel-start">
        <calcite-panel heading="Layers">
          <arcgis-layer-list reference-element="map"></arcgis-layer-list>
        </calcite-panel>
      </calcite-shell-panel>

      <!-- Map -->
      <arcgis-map id="map" basemap="streets-vector">
        <arcgis-zoom slot="top-left"></arcgis-zoom>
      </arcgis-map>

      <!-- End Panel -->
      <calcite-shell-panel slot="panel-end">
        <calcite-panel heading="Legend">
          <arcgis-legend reference-element="map"></arcgis-legend>
        </calcite-panel>
      </calcite-shell-panel>
    </calcite-shell>
  </body>
</html>

Calcite Action Bar

<calcite-shell>
  <calcite-shell-panel slot="panel-start">
    <calcite-action-bar slot="action-bar">
      <calcite-action
        icon="layers"
        text="Layers"
        data-panel="layers"
      ></calcite-action>
      <calcite-action
        icon="legend"
        text="Legend"
        data-panel="legend"
      ></calcite-action>
      <calcite-action
        icon="bookmark"
        text="Bookmarks"
        data-panel="bookmarks"
      ></calcite-action>
    </calcite-action-bar>

    <calcite-panel id="layers" heading="Layers">
      <arcgis-layer-list reference-element="map"></arcgis-layer-list>
    </calcite-panel>

    <calcite-panel id="legend" heading="Legend" hidden>
      <arcgis-legend reference-element="map"></arcgis-legend>
    </calcite-panel>
  </calcite-shell-panel>

  <arcgis-map id="map" basemap="topo-vector"></arcgis-map>
</calcite-shell>

<script>
  document.querySelectorAll("calcite-action").forEach((action) => {
    action.addEventListener("click", () => {
      const panelId = action.dataset.panel;
      document.querySelectorAll("calcite-panel").forEach((panel) => {
        panel.hidden = panel.id !== panelId;
      });
    });
  });
</script>

Common Calcite Components

Theming

<!-- Light mode -->
<body class="calcite-mode-light">
  <!-- Dark mode -->
  <body class="calcite-mode-dark">
    <!-- Custom theme colors -->
    <style>
      :root {
        --calcite-color-brand: #007ac2;
        --calcite-color-brand-hover: #005a8e;
        --calcite-color-text-1: #323232;
      }
    </style>
  </body>
</body>

Widget Events

// Search select
search.on("select-result", (event) => {
  console.log(event.result);
});

// LayerList trigger action
layerList.on("trigger-action", (event) => {
  console.log(event.action, event.item);
});

// FeatureTable selection
featureTable.highlightIds.on("change", (event) => {
  console.log(event.added, event.removed);
});

Reference Samples

• legend - Legend widget for layer symbology
• widgets-layerlist - LayerList widget for layer management
• widgets-search-multiplesource - Search widget with multiple sources
• widgets-featuretable - FeatureTable widget integration
• basemap-gallery - BasemapGallery for switching basemaps
• widgets-timeslider - TimeSlider widget for temporal data

Common Pitfalls

1. Missing reference-element: Components placed outside the <arcgis-map> tag cannot find the view without an explicit reference.

   <!-- Anti-pattern: component outside arcgis-map with no reference -->
   <arcgis-map id="myMap" basemap="topo-vector"></arcgis-map>
   <arcgis-search></arcgis-search>
   <!-- Cannot find the view -->

   <!-- Correct: use reference-element to link to the map -->
   <arcgis-map id="myMap" basemap="topo-vector"></arcgis-map>
   <arcgis-search reference-element="myMap"></arcgis-search>

   Impact: The component cannot discover the associated view. It either does not render or throws an error.

2. Slot names are specific: Use exact slot names (top-left, not topleft).
3. Calcite CSS not loading: Ensure Calcite script is loaded before using Calcite components.

4. Widget container conflicts: Do not add the same widget to both a DOM container and view.ui.

   // Anti-pattern: widget in both container and view.ui
   const legend = new Legend({ view: view, container: "legendDiv" });
   view.ui.add(legend, "bottom-right"); // Conflicts

   // Correct: pick one placement strategy
   const legend = new Legend({ view: view });
   view.ui.add(legend, "bottom-right");

   Impact: The widget renders twice or the layout breaks.

5. Dark/light mode mismatch: Add calcite-mode-light or calcite-mode-dark class to body.
6. Core API widgets missing CSS: When using Core API widgets (not Map Components), you must import @arcgis/core/assets/esri/themes/light/main.css. Map Components handle CSS automatically.

Related Skills

• See arcgis-widgets-advanced for specialized widgets (BuildingExplorer, FloorFilter, Track, Locate, etc.)
• See arcgis-map-tools for measurement, print, directions, and swipe tools
• See arcgis-editing for Editor and Sketch widgets
• See arcgis-tables-forms for FeatureTable and FeatureForm details