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Labeling | Overview | ArcGIS Maps SDK for JavaScript 4.33

Labels help identify features, establish a visual hierarchy of important features, and focus the user's attention on the map's purpose. Label options and capabilities (such as label placement and available fonts) vary depending on the layer type, geometry type, and view type (2D or 3D).

This guide page will demonstrate the possible labeling scenarios based on those different properties and fonts. The FAQ at the bottom contains information about useful workflows and answers to common questions. Additionally, this guide page will explore labeling adjacent use cases, such as text in TextSymbol and TextSymbol3DLayer, for text symbol previews using symbolUtils.renderPreviewHTML, and print considerations.

2D MapView labeling

Labeling is supported for FeatureLayer, CSVLayer, GeoJSONLayer, StreamLayer, OGCFeatureLayer, and WFSLayer in 2D MapViews. The labelingInfo property is specified as an array of LabelClass objects, which contains labelExpressionInfo, labelPlacement, and TextSymbol. The TextSymbol class supports altering the label graphic's color, font, halo, and other properties. Labeling is supported for Points, Polylines, and Polygons.

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const labelClass = {
  // autocasts as new LabelClass()
  symbol: {
    type: "text", // autocasts as new TextSymbol()
    color: "white",
    haloColor: "blue",
    haloSize: 1,
    font: {
      // autocast as new Font()
      family: "Noto Sans",
      size: 14,
    },
  },
  labelPlacement: "above-right",
  labelExpressionInfo: {
    expression: "$feature.Team + TextFormatting.NewLine + $feature.Division",
  },
  maxScale: 0,
  minScale: 25000000,
  where: "Conference = 'AFC'",
};

const labelLayer = new FeatureLayer({
  portalItem: {
    // autocasts as new PortalItem()
    id: "7f0bfc7bf67a407d8efebf584f6d956d",
  },
  labelingInfo: [labelClass],
});

Sample: Multi-line labels

3D SceneView labeling

Labeling is supported for all layer types with a labelingInfo property, such as FeatureLayer and SceneLayer. This property is specified as an array of LabelClass objects, which contains the labelExpressionInfo, labelPlacement, and TextSymbol3DLayer. The TextSymbol3DLayer class supports altering the label graphic's material, font, halo, and other properties.

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const labelClass = {
  // autocasts as new LabelClass()
  symbol: {
    type: "label-3d", // autocasts as new LabelSymbol3D()
    symbolLayers: [
      {
        type: "text", // autocasts as new TextSymbol3DLayer()
        material: {
          color: "purple",
        },
        font: {
          // autocasts as new Font()
          family: "Just Another Hand",
          weight: "bold",
        },
        size: 22,
      },
    ],
  },
  labelPlacement: "below-center",
  labelExpressionInfo: {
    expression: 'DefaultValue($feature.CITY_NAME, "no data")',
  },
};

const labelLayer = new FeatureLayer({
  url: "https://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/CITIES_EastUSA/FeatureServer/0",
  labelingInfo: [labelClass],
});

Known Limitations (SceneView)

Currently a feature can only have one label. If a feature satisfies the where condition of multiple LabelClasses, then only the label corresponding to the first matching LabelClass is displayed.
Label placement only applies to Point layers.
If the TextSymbol3DLayer.size property is set, it will override the Font.size property.

Sample: Flat vs. volumetric 3D symbol layers

Fonts

Typically, you won't need to be concerned with where the font files are hosted or which file types are used. However, if you are working with custom fonts or in a disconnected environment, it is worth reading this entire section. There are different types of font files used for labeling that are accessible from different locations, depending on the class, layer type, and if you are working in 2D or 3D. There are multiple ways that fonts can be consumed:

From https://static.arcgis.com/fonts in pbf format
From https://static.arcgis.com/fonts/woff2 in woff2 format
Referenced from a server in pbf, otf, ttf, woff, or woff2 format
From the fonts available on the user's computer and web browser

MapImageLayer fonts

MapImageLayer fonts come from a web browser or the user's computer.

Labeling is supported for MapImageLayer by setting the labelingInfo property on the Sublayer class. The labelingInfo property is specified as an array of LabelClass objects, containing the labelExpression, labelPlacement, and TextSymbol. The TextSymbol class supports altering the label graphic's color, font, halo, and other properties. Labeling is supported for Points, Polylines, and Polygons.

The supported font families for MapImageLayers in a MapView depend on the fonts installed on the ArcGIS Server that published the layer. This is the same for 2D MapViews and 3D SceneViews. To check what fonts are available on ArcGIS Server, run the Available Fonts task under Home > services > System > PublishingTools (GPServer) (requires admin access). To add a new font, the font must be installed on your computer and accessible to ArcGIS Server by registering it using ArcGIS Desktop. If an app uses a font that is not installed, the Font class implements a fallback mechanism that will use the default font family value, which is sans-serif.

Sample: MapImageLayer - label sublayer features

Non-MapImageLayer fonts

Support for Font.family, Font.style, and Font.weight properties are based on the fonts files. We host many fonts on https://static.arcgis.com/fonts that can be easily accessed for labeling.

If a Font is unavailable, it will use the default font family, sans-serif. This uses the Arial Unicode MS font file. Fonts with bold and/or italic require these properties to be set in the Font.style and Font.weight properties, as opposed to being set in the Font.family. To see which fonts support what types of characters (e.g. Latin, Cyrillic, CJKV), you can search for the font name in the Microsoft Typography or Google Fonts.

Non-MapImageLayer layers that can be labeled:
CSVLayer, FeatureLayer, GeoJSONLayer, OGCFeatureLayer, StreamLayer, WFSLayer.

List of fonts currently hosted on https://static.arcgis.com/fonts in pbf and woff2 formats (currently Palatino Linotype Regular, Arial Regular, Arial Bold, Arial Bold Italic, and Arial Italic are only available in pbf):

Preview: Code:

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SceneView fonts

The supported font families for 3D SceneViews are dependent upon (in order of precedence): the fonts installed on the user's computer and web browser, and then the fonts available on https://static.arcgis.com/fonts/woff2 or referenced from a server. If an app uses a font not installed on the user's computer and web browser, the app will search our hosted fonts. If a Font is unavailable there, the Font class implements a fallback mechanism that will use the default font family value, sans-serif. See these references for instructions on how to install a new font on Windows or Mac.

Note that these fonts also apply to TextSymbol3DLayer, whether it's used as graphics or labels in a 3D SceneView.

Fonts that are not installed locally can also be loaded from a url by defining a @font-face in a css file:

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@font-face {
  font-family: "MyFont";
  font-style: normal;
  font-weight: 400;
  font-display: auto;
  src: url("./my-font.ttf") format("truetype");
}

And referencing it from the Font.family property in a symbol layer:

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const labelSymbol = {
  type: "label-3d", // autocasts as new LabelSymbol3D
  symbolLayers: [
    {
      type: "text", // autocasts as new TextSymbol3DLayer()
      material: {
        color: [0, 0, 0, 0.8],
      },
      font: {
        size: 30,
        family: "MyFont",
      },
    },
  ],
};

Fonts can also be referenced from https://static.arcgis.com/fonts/woff2 by default:

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const labelClass = {
  // autocasts as new LabelClass()
  symbol: {
    type: "label-3d", // autocasts as new LabelSymbol3D()
    symbolLayers: [
      {
        type: "text", // autocasts as new TextSymbol3DLayer()
        material: {
          color: "black",
        },
        halo: {
          color: [255, 255, 255, 0.7],
          size: 2,
        },
        font: {
          family: "Noto Sans",
        },
        size: 10,
      },
    ],
  },
  labelPlacement: "above-right",
  labelExpressionInfo: {
    expression: `$feature.NAME + TextFormatting.NewLine + Text($feature.HOEHE, "#,### m")`,
  },
};

const labelLayer = new FeatureLayer({
  url: "https://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/AlpineSummits/FeatureServer/0",
  elevationInfo: {
    mode: "relative-to-ground",
  },
  labelingInfo: [labelClass],
});

Custom fonts and disconnected environments

In 2D MapViews, the fonts files used are pbf for all non-MapImageLayer layers and for TextSymbol, and woff2 for renderPreviewHTML.

In 3D SceneViews, the fonts files used are ttf, otf, woff, or woff2 format for all non-MapImageLayer layers and for TextSymbol3DLayer, and woff2 for renderPreviewHTML. Also, for 3D SceneViews, font files from https://static.arcgis.com/fonts are only consumed in woff2 format.

By default, the fonts available are mostly the same ones used by the Esri Vector Basemaps. These fonts are listed in the Esri Vector Basemap Reference Document, under the Esri Vector Basemaps Resources\Fonts heading. These fonts are available via https://static.arcgis.com/fonts. Access to that URL is required for the app to render labels. If this URL is not accessible (e.g. disconnected or offline environment), or a font is being used that is not hosted there, then the fontsUrl can be configured to point to your own font files by setting the esriConfig.fontsUrl property. These font files must be the correct file type to display. Reference the table below to see the required types of font files based on the class and if you are working in 2D or 3D.

View Applied to Font source 2D & 3D MapImageLayer User's computer and web browser (ttf, otf, woff, or woff2 format) 2D & 3D renderPreviewHTML https://static.arcgis.com/fonts/woff2 (woff2 format)
hosted on a server (woff2 format) 2D MapView Non-MapImageLayer https://static.arcgis.com/fonts (pbf format)
hosted on a server (pbf format) 3D SceneView Non-MapImageLayer User's computer and web browser
https://static.arcgis.com/fonts/woff2 (woff2 format)
referenced from a server (ttf, otf, woff, or woff2 format)

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esriConfig.fontsUrl = "https://myserver.com/fonts"; // reference fonts from a server in `pbf`

const labelClass = {
  // autocasts as new LabelClass()
  symbol: {
    type: "text", // autocasts as new TextSymbol()
    color: "white",
    haloColor: "blue",
    haloSize: 1,
    font: {
      // autocast as new Font()
      family: "Wes Welker",
      size: 83,
    },
  },
  labelPlacement: "above-right",
  labelExpressionInfo: {
    expression: "$feature.Team + TextFormatting.NewLine + $feature.Division",
  },
  maxScale: 0,
  minScale: 25000000,
  where: "Conference = 'AFC'",
};

const labelLayer = new FeatureLayer({
  portalItem: {
    // autocasts as new PortalItem()
    id: "7f0bfc7bf67a407d8efebf584f6d956d",
  },
  labelingInfo: [labelClass],
});

Alternative labeling scenarios

Additionally, this guide page will explore labeling adjacent use cases. The labeling workflow doesn't end with labeling layers. There are other ways to label features, as well as other app considerations for those labeled features.

TextSymbol and TextSymbol3DLayer

TextSymbol and TextSymbol3DLayer are both part of the typical labeling workflow, and can also be used in an alternative labeling experience. These symbols can be used as individual labels themselves, with the label's font and text representing the visualization.

Here is an example of a TextSymbol being added to 2D MapView with formatted text:

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const textSymbol = {
  type: "text", // autocasts as new TextSymbol()
  color: "blue",
  haloColor: "red",
  haloSize: "1px",
  text: "Wish you were here",
  xoffset: 3,
  yoffset: 3,
  font: {
    // autocasts as new Font()
    size: 12,
    family: "Orbitron",
    weight: "bold",
  },
};

const point = {
  type: "point", // autocasts as new Point()
  longitude: -71.26,
  latitude: 42.09,
};

const pointGraphic = new Graphic({
  geometry: point,
  symbol: textSymbol,
});

view.graphics.add(pointGraphic);

Here is an example of a TextSymbol3DLayer being added to a 3D SceneView with formatted text:

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const textSymbol3D = {
  type: "point-3d", // autocasts as new PointSymbol3D()
  symbolLayers: [
    {
      type: "text", // autocasts as new TextSymbol3DLayer()
      font: {
        // autocasts as new Font()
        size: 12,
        family: "Just Another Hand",
      },
      text: "Wish I was here",
      material: {
        color: "green",
      },
      size: 12,
    },
  ],
};

const point = {
  type: "point", // autocasts as new Point()
  longitude: -71.26,
  latitude: 42.09,
};

const pointGraphic3D = new Graphic({
  geometry: point,
  symbol: threeDpoint,
});

view.graphics.add(pointGraphic3D);

Esri Icon font

The Esri Icon font can be used as the font.family property of the LabelClass for some layers. In the code snippet below, a LabelClass is created by autocasting the symbol type as text, the color, and font. Lastly, we defined the labelPlacement and the labelExpressionInfo.

Layers that can be labeled with Esri Icon font:
CSVLayer, FeatureLayer, GeoJSONLayer, OGCFeatureLayer, StreamLayer, WFSLayer.

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const labelClass = {
  // autocasts as new LabelClass()
  symbol: {
    type: "text", // autocasts as new TextSymbol()
    color: "green",
    font: {
      // autocast as new Font()
      family: "CalciteWebCoreIcons",
      size: 12,
    },
  },
  labelPlacement: "above-left",
  labelExpressionInfo: {
    expression: '"\ue61d"', // esri-icon-map-pin
  },
};

const fl = new FeatureLayer({
  url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3",
  labelingInfo: labelClass,
});

renderPreviewHTML

The symbolUtils class is used to generate small preview images of symbols. This utility can be useful when you have a workflow that requires displaying small previews of symbols used to represent features in a layer. The renderPreviewHTML() method generates a preview image of a given symbol that can be displayed in a custom widget or other DOM element, including a label. The font file (in woff2 format) for this label comes from either our hosted font files, or hosted on a server if using a different source via esriConfig.fontsUrl.

Printing

There are a few considerations to keep in mind when printing a map with labels (printing is currently only supported in 2D MapViews). There is currently no support for printing rotated labels when the map is rotated. Labels cannot be printed as part of a FeatureLayer with ArcGIS Server 10.5.1 or earlier, or with a printing service published with ArcMap. The source for font files must be accessible to the printing service for the labels to appear in a printed map, so if the files are hosted on a private server, the print service must also have access to that private server.

FAQ

This FAQ contains information about useful workflows and answers to common questions!

How do you create new lines in labels?

Labels can be separated into multiple lines using template literals, or using the TextFormatting.NewLine Arcade constant. Here, MARKER_ACTIVITY will be on the first line, and RECAREANAM will be on a new line. Examples:

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// template literal
"$feature.MARKER_ACTIVITY + '\\n' + $feature.RECAREANAM";

// TextFormatting.NewLine
"$feature.MARKER_ACTIVITY + TextFormatting.NewLine + $feature.RECAREANAM";

Where can I find more labeling resources?

What about labels from basemaps?

A basemap can contain base layers, which comprise one or more layers, and reference layers. Reference layers are displayed on top of the base layer and all other layers in the map, and can be used to display labels on top of terrain or streets. Labels from reference layers will be placed at the top, and labels from base layers will display at the same level as the basemap's base layers.

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