WMSLayer

Property Overview

Property Details

allSublayers Collection<WMSSublayer>

Since: ArcGIS Maps SDK for JavaScript 4.17

A flattened collection of all WMSSublayers based on the sublayers property.

Example

// Print the names of all sublayers used for rendering.
const layer = new WMSLayer({
  url: "https://geo.weather.gc.ca/geomet"
});
layer.load().then(() => {
  const names = layer.allSublayers
                     .filter((sublayer) => !sublayer.sublayers) // Non-grouping layers will not have any "sublayers".
                     .map((sublayer) => sublayer.name);
  console.log("Names of all child sublayers", names.join());
});

blendMode String

Since: ArcGIS Maps SDK for JavaScript 4.16

Blend modes are used to blend layers together to create an interesting effect in a layer, or even to produce what seems like a new layer. Unlike the method of using transparency which can result in a washed-out top layer, blend modes can create a variety of very vibrant and intriguing results by blending a layer with the layer(s) below it.

When blending layers, a top layer is a layer that has a blend mode applied. All layers underneath the top layer are background layers. The default blending mode is normal where the top layer is simply displayed over the background layer. While this default behavior is perfectly acceptable, the use of blend modes on layers open up a world of endless possibilities to generate creative maps.

The layers in a GroupLayer are blended together in isolation from the rest of the map.

In the following screenshots, the vintage shaded relief layer is displayed over a firefly world imagery layer. The color blend mode is applied to the vintage shaded relief and the result looks like a new layer.

Known Limitations

• The blendMode in 3D SceneViews is supported on BaseTileLayer, ImageryTileLayer, OpenStreetMapLayer, TileLayer, VectorTileLayer, WCSLayer, WebTileLayer, WMTSLayer and GroupLayer.
• The blendMode is not supported in the Legend.
• See print for known printing limitations.

The following factors will affect the blend result:

• Order of all layers
• Layer opacity
• Opacity of features in layers
• Visibility of layers
• By default, the very bottom layer in a map is drawn on a transparent background. You can change the MapView's background color.

Blend mode	Description
normal	The top layer is displayed over the background layer. The data of the top layer block the data of background layer where they overlap.
average	Takes the mathematical average of top and background layers. Result of average blend mode is often similar to the effect of setting the layer's opacity to 50%.

Lighten blend modes:

The following blend modes create lighter results than all layers. In lighten blend modes, pure black colors in the top layer become transparent allowing the background layer to show through. White in the top layer will stay unchanged. Any color that is lighter than pure black is going to lighten colors in the top layer to varying degrees all way to pure white.

Lighten blend modes can be useful when lightening dark colors of the top layer or removing black colors from the result. The plus, lighten and screen modes can be used to brighten layers that have faded or dark colors on a dark background.

Blend mode	Description
lighten	Compares top and background layers and retains the lighter color. Colors in the top layer become transparent if they are darker than the overlapping colors in the background layer allowing the background layer to show through completely. Can be thought of as the opposite of darken blend mode.
lighter	Colors in top and background layers are multiplied by their alphas (layer opacity and layer's data opacity. Then the resulting colors are added together. All overlapping midrange colors are lightened in the top layer. The opacity of layer and layer's data will affect the blend result.
plus	Colors in top and background layers are added together. All overlapping midrange colors are lightened in the top layer. This mode is also known as add or linear-dodge.
screen	Multiplies inverted colors in top and background layers then inverts the colors again. The resulting colors will be lighter than the original color with less contrast. Screen can produce many different levels of brightening depending on the luminosity values of the top layer. Can be thought of as the opposite of the multiply mode.
color-dodge	Divides colors in background layer by the inverted top layer. This lightens the background layer depending on the value of the top layer. The brighter the top layer, the more its color affects the background layer. Decreases the contrast between top and background layers resulting in saturated mid-tones and blown highlights.

Darken blend modes:

The following blend modes create darker results than all layers. In darken blend modes, pure white in the top layer will become transparent allowing the background layer to show through. Black in the top layer will stay unchanged. Any color that is darker than pure white is going to darken a top layer to varying degrees all the way to pure black.

The multiply blend mode is often used to highlight shadows, show contrast, or accentuate an aspect of a map. For example, you can use multiply blend mode on a topographic map displayed over hillshade when you want to have your elevation show through the topographic layer. See the intro to layer blending sample.

The multiply and darken modes can be used to have dark labels of the basemap to show through top layers. See the darken blending sample.

The color-burn mode works well with colorful top and background layers since it increases saturation in mid-tones. It increases the contrast by tinting pixels in overlapping areas in top and bottom layers more towards the top layer color. Use this blend mode, when you want an effect with more contrast than multiply or darken.

The following screenshots show how the multiply blend mode used for creating a physical map of the world that shows both boundaries and elevation.

Blend mode	Description
darken	Emphasizes the darkest parts of overlapping layers. Colors in the top layer become transparent if they are lighter than the overlapping colors in the background layer, allowing the background layer to show through completely.
multiply	Emphasizes the darkest parts of overlapping layers by multiplying colors of the top layer and the background layer. Midrange colors from top and background layers are mixed together more evenly.
color-burn	Intensifies the dark areas in all layers. It increases the contrast between top and background layers, by tinting colors in overlapping area towards the top color. To do this it inverts colors of the background layer, divides the result by colors of the top layer, then inverts the results.

Contrast blend modes:

The following blend modes create contrast by both lightening the lighter areas and darkening the darker areas in the top layer by using lightening or darkening blend modes to create the blend. The contrast blend modes will lighten the colors lighter than 50% gray ([128,128,128]), and darken the colors darker than 50% gray. 50% gray will be transparent in the top layer. Each mode can create a variety of results depending on the colors of top and background layers being blended together. The overlay blend mode makes its calculations based on the brightness of the colors in the background layer while all of the other contrast blend modes make their calculations based on the brightness of the top layer. Some of these modes are designed to simulate the effect of shining a light through the top layer, effectively projecting upon the layers beneath it.

Contrast blend modes can be used to increase the contrast and saturation to have more vibrant colors and give a punch to your layers. For example, you can duplicate a layer and set overlay blend mode on the top layer to increase the contrast and tones of your layer. You can also add a polygon layer with a white fill symbol over a dark imagery layer and apply soft-light blend mode to increase the brightness in the imagery layer.

The following screenshots show an effect of the overlay blend mode on a GraphicsLayer. The left image shows when the buffer graphics layer has the normal blend mode. As you can see, the gray color for the buffer polygon is blocking the intersecting census tracts. The right image shows when the overlay blend mode is applied to the buffer graphics layer. The overlay blend mode darkens or lightens the gray buffer polygon depending on the colors of the background layer while the census tracts layer is shining through. See this in action.

Normal blend mode	Overlay blend mode

Blend mode	Description
overlay	Uses a combination of multiply and screen modes to darken and lighten colors in the top layer with the background layer always shining through. The result is darker color values in the background layer intensify the top layer, while lighter colors in the background layer wash out overlapping areas in the top layer.
soft-light	Applies a half strength screen mode to lighter areas and half strength multiply mode to darken areas of the top layer. You can think of the soft-light as a softer version of the overlay mode.
hard-light	Multiplies or screens the colors, depending on colors of the top layer. The effect is similar to shining a harsh spotlight on the top layer.
vivid-light	Uses a combination of color-burn or color-dodge by increasing or decreasing the contrast, depending on colors in the top layer.

Component blend modes:

The following blend modes use primary color components, which are hue, saturation and luminosity to blend top and background layers. You can add a feature layer with a simple renderer over any layer and set hue, saturation, color or luminosity blend mode on this layer. With this technique, you create a brand new looking map.

The following screenshots show where the topo layer is blended with world hillshade layer with luminosity blend mode. The result is a drastically different looking map which preserves the brightness of the topo layer while adapting the hue and saturation of the hillshade layer.

Blend mode	Description
hue	Creates an effect with the hue of the top layer and the luminosity and saturation of the background layer.
saturation	Creates an effect with the saturation of the top layer and the hue and luminosity of the background layer. 50% gray with no saturation in the background layer will not produce any change.
luminosity	Creates effect with the luminosity of the top layer and the hue and saturation of the background layer. Can be thought of as the opposite of color blend mode.
color	Creates an effect with the hue and saturation of the top layer and the luminosity of the background layer. Can be thought of as the opposite of luminosity blend mode.

Composite blend modes:

The following blend modes can be used to mask the contents of top, background or both layers.

• Destination modes are used to mask the data of the top layer with the data of the background layer.
• Source modes are used to mask the data of the background layer with the data of the top layer.

The destination-in blend mode can be used to show areas of focus such as earthquakes, animal migration, or point-source pollution by revealing the underlying map, providing a bird’s eye view of the phenomenon. Check out multiple blending and groupLayer blending samples to see composite blend modes in action.

The following screenshots show feature and imagery layers on the left side on their own in the order they are drawn in the view. The imagery layer that contains land cover classification rasters. The feature layer contains 2007 county crops data. The right image shows the result of layer blending where destination-in blendMode is set on the imagery layer. As you can see, the effect is very different from the original layers. The blended result shows areas of cultivated crops only (where both imagery and feature layers overlap).

Blend mode	Description
destination-over	Destination/background layer covers the top layer. The top layer is drawn underneath the destination layer. You'll see the top layer peek through wherever the background layer is transparent or has no data.
destination-atop	Destination/background layer is drawn only where it overlaps the top layer. The top layer is drawn underneath the background layer. You'll see the top layer peek through wherever the background layer is transparent or has no data.
destination-in	Destination/background layer is drawn only where it overlaps with the top layer. Everything else is made transparent.
destination-out	Destination/background layer is drawn where it doesn't overlap the top layer. Everything else is made transparent.
source-atop	Source/top layer is drawn only where it overlaps the background layer. You will see the background layer peek through where the source layer is transparent or has no data.
source-in	Source/top layer is drawn only where it overlaps with the background layer. Everything else is made transparent.
source-out	Source/top layer is drawn where it doesn't overlap the background layer. Everything else is made transparent.
xor	Top and background layers are made transparent where they overlap. Both layers are drawn normal everywhere else.

Invert blend modes:

The following blend modes either invert or cancel out colors depending on colors of the background layer. These blend modes look for variations between top and background layers. For example, you can use difference or exclusion blend modes on two imagery layers of forest covers to visualize how forest covers changed from one year to another.

The invert blend mode can be used to turn any light basemap into a dark basemap to accommodate those who work in low-light conditions. The following screenshots show how setting the invert blend mode set on a feature layer with a simple renderer turns the world terrain basemap into a dark themed basemap in no time.

Blend mode	Description
difference	Subtracts the darker of the overlapping colors from the lighter color. When two pixels with the same value are subtracted, the result is black. Blending with black produces no change. Blending with white inverts the colors. This blending mode is useful for aligning layers with similar content.
exclusion	Similar to the difference blend mode, except that the resulting image is lighter overall. Overlapping areas with lighter color values are lightened, while darker overlapping color values become transparent.
minus	Subtracts colors of the top layer from colors of the background layer making the blend result darker. In the case of negative values, black is displayed.
invert	Inverts the background colors wherever the top and background layers overlap. The invert blend mode inverts the layer similar to a photographic negative.
reflect	This blend mode creates effects as if you added shiny objects or areas of light in the layer. Black pixels in the background layer are ignored as if they were transparent.

Possible Values:"average"|"color-burn"|"color-dodge"|"color"|"darken"|"destination-atop"|"destination-in"|"destination-out"|"destination-over"|"difference"|"exclusion"|"hard-light"|"hue"|"invert"|"lighten"|"lighter"|"luminosity"|"minus"|"multiply"|"normal"|"overlay"|"plus"|"reflect"|"saturation"|"screen"|"soft-light"|"source-atop"|"source-in"|"source-out"|"vivid-light"|"xor"

Default Value:normal

See also

• Layer blending samples

copyright String

Copyright information for the WMS service. This defaults to the value of the AccessConstraints property from the GetCapabilities request.

customLayerParameters Object

Use this to append different custom parameters to the WMS map requests. The custom layer parameters are applied to GetMap and GetFeatureInfo.

customParameters Object

Use this to append custom parameters to all WMS requests. The custom parameters are applied to GetCapabilities, GetMap and GetFeatureInfo. For example, if an access key is required, the key can be configured as a custom parameter. The layer's refresh() method needs to be called if the customParameters are updated at runtime.

declaredClass Stringreadonly inherited

Since: ArcGIS Maps SDK for JavaScript 4.7

The name of the class. The declared class name is formatted as esri.folder.className.

description String

Description for the WMS layer. This defaults to the value of the Abstract property from the WMS GetCapabilities request.

dimensions Array<(TimeDimension|ElevationDimension|GenericDimension)>readonly

Since: ArcGIS Maps SDK for JavaScript 4.20

An array of time, elevation and other dimensions for the root layer. Information from a TimeDimension can be used to update View.timeExtent, WMSLayer.timeExtent, or to configure a TimeSlider widget.

A WMSLayer or WMSSublayer can only have one time dimension. The following example shows how to find the time dimension (if any) for the base layer.

const layer = new WMSLayer({
  url: "https://public-wms.met.no/verportal/verportal.map?request=GetCapabilities&service=WMS&version=1.3.0"
});
await layer.load();
const timeDimension = layer.dimensions.find((dimension) => dimension.name === "time");

Data can exist at specific times or time ranges. We can access this information from the extent property of the TimeDimension as either an array of discrete dates or TimeDimensionIntervals. For example, continuing from the previous example, a TimeSlider is configured using the extent from a TimeDimension.

const dates = timeDimension.extent; // This time dimension is expressed as an array of dates.
const start = dates[0]; // Get the first and earliest date
const end = dates[dates.length -1]; // Get last date
const timeSlider = new TimeSlider({
  container: "timeSliderDiv",
  view: view,
  mode: "instant",
  timeVisible: true,
  loop: true,
  fullTimeExtent: { // The TimeSlider UI will span all dates
    start,
    end
  },
  stops: {
    dates // The TimeSlider thumb will snap exactly to each valid date
  }
})

effect Effectautocast

Since: ArcGIS Maps SDK for JavaScript 4.18

Effect provides various filter functions that can be performed on the layer to achieve different visual effects similar to how image filters work. This powerful capability allows you to apply css filter-like functions to layers to create custom visual effects to enhance the cartographic quality of your maps. This is done by applying the desired effect to the layer's effect property as a string or an array of objects to set scale dependent effects.

Notes

• Set featureEffect property if different effects need to be applied features that meet or fail a specified filter.
• If all of the following four properties are applied, then they will be applied in this order: featureEffect, effect, opacity and blendMode.

Known Limitations

• The effect is not supported in 3D SceneViews.
• The effect cannot be applied to a layer with a heatmap renderer.
• The effect is not supported in layers with featureReduction of type cluster enabled.
• See print for known printing limitations.

Default Value:null

See also

• featureEffect

• More information on how to set effect

• Layer and layer view effect samples

Examples

// the following effect will be applied to the layer at all scales
// brightness will be applied first, then hue-rotate followed by contrast
// changing order of the effects will change the final result
layer.effect = "brightness(5) hue-rotate(270deg) contrast(200%)";

// set a scale dependent bloom effect on the layer
layer.effect = [
  {
    scale: 36978595,
    value: "drop-shadow(3px, 3px, 4px)"
  },
  {
    scale: 18489297,
    value: "drop-shadow(2px, 2px, 3px)"
  },
  {
    scale: 4622324,
    value: "drop-shadow(1px, 1px, 2px)"
  }
];

featureInfoFormat String|null

The MIME type that will be requested by popups.

The only valid values are "text/html" and "text/plain" or whichever is support by the service with "text/html" being preferred. For a list of all supported MIME types please refer to featureInfoFormats.

Example

// Display the MIME-type that will requested by popups.
const layer = new WMSLayer({
  url: "http://ows.terrestris.de/osm/service",
});
await layer.load();
console.log(layer.featureInfoFormat); // text/html

featureInfoFormats String[]readonly

Since: ArcGIS Maps SDK for JavaScript 4.25

This property lists all available MIME-types that can be used with the WMS service's GetFeatureInfo request. The GetFeatureInfo request is indirectly used by popups.

To take advantage of unsupported MIME-types, such as application/json, please refer to fetchFeatureInfoFunction.

Example

// Display a list of MIME-types supported by the WMS service's _GetFeatureInfo_ request.
const layer = new WMSLayer({
  url: "https://maps.dwd.de/geoserver/dwd/wms"
});
await layer.load();
console.log(layer.featureInfoFormats);
// ["text/plain", "application/vnd.ogc.gml", "text/xml", "application/vnd.ogc.gml/3.1.1", "text/xml; subtype=gml/3.1.1", "text/html", "text/javascript", "application/json"]

featureInfoUrl String

The URL for the WMS GetFeatureInfo call.

Example

// The following snippet demonstrates how to retrieve feature information from a WMSLayer
//   when the View is clicked. This snippet assumes that the service associated with the
//   layer supports a GetFeatureInfo MIME-type of "application/json".
view.on("click", async ({ x, y }) => {
  // Get a comma delimited list of visible layers.
  const layers = layer.sublayers
    .filter(({ visible, queryable, name }) => visible && queryable && name)
    .map(({ name }) => name)
    .join();

  const { xmin, ymin, xmax, ymax, spatialReference: { latestWkid, wkid} } = view.extent;
  const bbox = `${xmin},${ymin},${xmax},${ymax}`;
  const crs = `EPSG:${latestWkid ?? wkid}`;

  const { data } = await request(layer.featureInfoUrl, {
    query: {
      SERVICE: "WMS",
      LAYERS: layers,
      QUERY_LAYERS: layers,
      REQUEST: "GetFeatureInfo",
      INFO_FORMAT: "application/json",
      FEATURE_COUNT: 5,
      BBOX: bbox,
      CRS: crs,
      WIDTH: view.width,
      HEIGHT: view.height,
      I: Math.round(x),
      J: Math.round(y)
    }
  });

  console.log("geoJson", data);
});

fetchFeatureInfoFunction FetchFeatureInfoFunction

Since: ArcGIS Maps SDK for JavaScript 4.25

Function to override the default popup behavior of WMSLayer.

By default, popups will make a GetFeatureInfo request specifying the featureInfoFormat mime-type. The featureInfoFormat property only supports text/plain or text/html.

Use fetchFeatureInfoFunction to take advantage of other mime-types supported by the service such as JSON or GeoJSON. See featureInfoFormats) for a list of supported mime-types.

Default Value:null

Example

const url = "https://maps.dwd.de/geoserver/dwd/wms";
const sublayerName = "RADOLAN-RW"; // title: "angeeichtes Radarkomposit (RW)"

const layer = new WMSLayer({
  url,
  fetchFeatureInfoFunction: async (query) => {
    // Explicitly request a GeoJSON response.
    query.info_format = "application/json";

    // Request the first five features (if any).
    query.feature_count = 5;

    // Perform the web request.
    const { data } = await esriRequest(layer.featureInfoUrl, { query });

    // Convert each GeoJSON feature into an Esri graphic.
    return data.features.map(
      (feature) => new Graphic({
        attributes: feature.properties,

        // Define a popup template to format field names and values in a table.
        popupTemplate: {
          title: "{id}",
          content: [{
            type: "fields",
            fieldInfos: [
              { fieldName: "GRAY_INDEX", label: "Gray Index" },
              { fieldName: "TIME", label: "Time" }
            ]
          }]
        }
      })
    );
  }
});

fullExtent Extentautocast inherited

The full extent of the layer. By default, this is worldwide. This property may be used to set the extent of the view to match a layer's extent so that its features appear to fill the view. See the sample snippet below.

Example

// Once the layer loads, set the view's extent to the layer's fullextent
layer.when(function(){
  view.extent = layer.fullExtent;
});

fullExtents Extent[]

All bounding boxes defined for the layer.

id String inherited

The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded.

imageFormat String

The map image format (MIME type) to request. Defaults to image/png if the WMS service supports it. If not, it defaults to the value of the first <Format> in <GetMap> in the GetCapabilities response.

imageMaxHeight Number

Indicates the maximum height of the image exported by the service.

Default Value:2048

imageMaxWidth Number

Indicates the maximum width of the image exported by the service.

Default Value:2048

imageTransparency Boolean

Indicates whether the background of the image exported by the service is transparent.

Default Value:true

legendEnabled Boolean

Indicates whether the layer will be included in the legend.

Default Value:true

listMode String inherited

Indicates how the layer should display in the LayerList widget. The possible values are listed below.

Value	Description
show	The layer is visible in the table of contents.
hide	The layer is hidden in the table of contents.
hide-children	If the layer is a GroupLayer, BuildingSceneLayer, KMLLayer, MapImageLayer, TileLayer or WMSLayer, hide the children layers from the table of contents.

Possible Values:"show"|"hide"|"hide-children"

Default Value:"show"

loaded Booleanreadonly inherited

Indicates whether the layer's resources have loaded. When true, all the properties of the object can be accessed.

Default Value:false

loadError Errorreadonly inherited

The Error object returned if an error occurred while loading.

Default Value:null

loadStatus Stringreadonly inherited

Represents the status of a load operation.

Value	Description
not-loaded	The object's resources have not loaded.
loading	The object's resources are currently loading.
loaded	The object's resources have loaded without errors.
failed	The object's resources failed to load. See loadError for more details.

Possible Values:"not-loaded"|"loading"|"failed"|"loaded"

Default Value:not-loaded

loadWarnings Object[]readonly inherited

A list of warnings which occurred while loading.

maxScale Number

The maximum scale (most zoomed in) at which the layer is visible in the view. If the map is zoomed in beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a maximum scale. The maxScale value should always be smaller than the minScale value, and greater than or equal to the service specification.

Default Value:0

Examples

// The layer will not be visible when the view is zoomed in beyond a scale of 1:1,000
layer.maxScale = 1000;

// The layer's visibility is not restricted to a maximum scale.
layer.maxScale = 0;

minScale Number

The minimum scale (most zoomed out) at which the layer is visible in the view. If the map is zoomed out beyond this scale, the layer will not be visible. A value of 0 means the layer does not have a minimum scale. The minScale value should always be larger than the maxScale value, and lesser than or equal to the service specification.

Default Value:0

Examples

// The layer will not be visible when the view is zoomed out beyond a scale of 1:3,000,000
layer.minScale = 3000000;

// The layer's visibility is not restricted to a minimum scale.
layer.minScale = 0;

opacity Number inherited

The opacity of the layer. This value can range between 1 and 0, where 0 is 100 percent transparent and 1 is completely opaque.

Default Value:1

Example

// Makes the layer 50% transparent
layer.opacity = 0.5;

portalItem PortalItem

The portal item from which the layer is loaded. If the portal item references a Feature Service or Scene Service, then you can specify a single layer to load with the layerId property.

Beginning with version 4.17, it is possible to load tables from feature service items hosted in ArcGIS Online and ArcGIS Enterprise. This only applies to feature layers, and will successfully load if FeatureLayer.isTable returns true.

Examples

// While this example uses FeatureLayer, this same pattern can be
// used for other layers that may be loaded from portalItem ids.
const layer = new FeatureLayer({
  portalItem: {  // autocasts as new PortalItem()
    id: "caa9bd9da1f4487cb4989824053bb847"
  }  // the first layer in the service is returned
});

// Set hostname when using an on-premise portal (default is ArcGIS Online)
// esriConfig.portalUrl = "http://myHostName.esri.com/arcgis";

// While this example uses FeatureLayer, this same pattern can be
// used for SceneLayers.
const layer = new FeatureLayer({
  portalItem: {  // autocasts as new PortalItem()
    id: "8d26f04f31f642b6828b7023b84c2188"
  },
  // loads the third item in the given feature service
  layerId: 2
});

// Initialize GeoJSONLayer by referencing a portalItem id pointing to geojson file.
const layer = new GeoJSONLayer({
  portalItem: new PortalItem({
    id: "81e769cd7031482797e1b0768f23c7e1",
    // optionally define the portal, of the item.
    // if not specified, the default portal defined is used.
    // see https://developers.arcgis.com/javascript/latest/api-reference/esri-config.html#portalUrl
    portal: new Portal({
      url: "https://jsapi.maps.arcgis.com/"
    })
  }
});

// This snippet loads a table hosted in ArcGIS Online.
const table = new FeatureLayer({
  portalItem: { // autocasts as esri/portal/PortalItem
    id: "123f4410054b43d7a0bacc1533ceb8dc"
  }
});

// Before adding the table to the map, it must first be loaded and confirm it is the right type.
table.load().then(function() {
  if (table.isTable) {
    map.tables.add(table);
  }
});

refreshInterval Number

Since: ArcGIS Maps SDK for JavaScript 4.6

Refresh interval of the layer in minutes. Value of 0 indicates no refresh.

Default Value:0

See also

• refresh()

• refresh event

Example

// the layer will be refreshed every 6 seconds.
layer.refreshInterval = 0.1;

spatialReference SpatialReference

The spatial reference of the layer.

spatialReferences Number[]

List of spatialReference well known ids derived from the CRS elements of the first layer in the GetCapabilities request.

sublayers Collection<WMSSublayer>

A subset of the layer's WMSSublayers that will be displayed.

timeExtent TimeExtentautocast

Since: ArcGIS Maps SDK for JavaScript 4.17

The layer's time extent. When the layer's useViewTime is false, the layer instructs the view to show data from the layer based on this time extent. If the useViewTime is true, and both layer and view time extents are set, then features that fall within the intersection of the view and layer time extents will be displayed. For example, if the layer's time extent is set to display features between 1970 and 1975 and the view has a time extent set to 1972-1980, the effective time on the feature layer will be 1972-1975.

Examples

if (!layer.useViewTime) {
  if (layer.timeExtent) {
    console.log("Current timeExtent:", layer.timeExtent.start, " - ", layer.timeExtent.end}
  } else {
    console.log("The layer will display data within the view's timeExtent.");
    console.log("Current view.timeExtent:", view.timeExtent.start, " - ", view.timeExtent.end}
  }
}

// set the timeExtent on the layer and useViewTime false
// In this case, the layer will honor its timeExtent and ignore
// the view's timeExtent
const layer = new WMSLayer({
  url: "https://geo.weather.gc.ca/geomet",
  timeExtent: {
    start: new Date(Date.UTC(2020, 8, 12)),
    end:  new Date(Date.UTC(2020, 8, 14)),
  },
  useViewTime: false
});

// timeExtent is set on the layer and the view
// In this case, the layer will display features that fall
// within the intersection of view and layer time extents
// features within Jan 1, 1976 - Jan 1, 1981 will be displayed
const view = new MapView({
  timeExtent: {
    start: new Date(1976, 0, 1),
    end: new Date(2002, 0, 1)
  }
});
const layer = new WMSLayer({
  url: myUrl,
  timeExtent: {
    start: new Date(1974, 0, 1),
    end: new Date(1981, 0, 1)
  }
});

timeInfo TimeInfoautocast

Since: ArcGIS Maps SDK for JavaScript 4.17

TimeInfo provides information such as date fields that store start and end time for each feature and the fullTimeExtent for the layer. The timeInfo property is automatically set at layer initialization if the layer has one or more time dimensions. The fullTimeExtent for timeInfo is automatically set to the union of all time dimension extents. The timeInfo parameters cannot be changed after the layer is loaded.

Default Value:null

timeOffset TimeIntervalautocast

Since: ArcGIS Maps SDK for JavaScript 4.17

A temporary offset of the time data based on a certain TimeInterval. This allows users to overlay features from two or more time-aware layers with different time extents. For example, if a layer has data recorded for the year 1970, an offset value of 2 years would temporarily shift the data to 1972. You can then overlay this data with data recorded in 1972. A time offset can be used for display purposes only. The query and selection are not affected by the offset.

Default Value:null

Example

// Offset a CSV Layer containing hurricanes from 2015 so that they appear in 2019 (+4 years).
let layer = new CSVLayer({
  url: `hurricanes-and-storms-2015.csv`,
  timeOffset: {
    value: 4,
    unit: "years"
  },
  timeInfo: {
    startField: "ISO_time"
  },
  renderer: {
    type: "simple",
    symbol: {
      type: "simple-marker",
      size: 6,
      color: "red",
      outline: {
        width: 0.5,
        color: "black"
      }
    }
  }
});

title String

The title of the layer used to identify it in places such as the Legend and LayerList widgets.

When the layer is loaded from a portal item, the title of the portal item will be used. If a layer is loaded as part of a webmap or a webscene, then the title of the layer as stored in the webmap/webscene will be used.

type Stringreadonly

For WMSLayer the type is always "wms".

url String

The URL of the WMS service.

useViewTime Boolean

Since: ArcGIS Maps SDK for JavaScript 4.17

Determines if the layer will update its temporal data based on the view's timeExtent. When false, the layer will display its temporal data based on the layer's timeExtent, regardless of changes to the view. If both view and layer time extents are set while this property is true, then the features that fall within the intersection of the view and layer time extents will be displayed. For example, if a layer's time extent is set to display features between 1970 and 1975 and the view has a time extent set to 1972-1980, the effective time on the feature layer will be 1972-1975.

Default Value:true

Example

if (wmsLayer.useViewTime) {
  console.log("Displaying data between:", view.timeExtent.start, " - ", view.timeExtent.end);
}

version String

Version of the WMS specification to use. For example, 1.3.0, 1.1.1, 1.1 or 1.0.

visible Boolean inherited

Indicates if the layer is visible in the View. When false, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.

Default Value:true

Example

// The layer is no longer visible in the view
layer.visible = false;

Method Overview

Method Details

addHandles(handleOrHandles, groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle[] Handles marked for removal once the object is destroyed.

groupKey * optional Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

cancelLoad()inherited

Cancels a load() operation if it is already in progress.

createLayerView(view, options){Promise<LayerView>}inherited

Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it. This method is used internally and there is no use case for invoking it directly.

Parameters

view * The parent view.

options Object optional An object specifying additional options. See the object specification table below for the required properties of this object. Specification signal AbortSignal optional A signal to abort the creation of the layerview.

Returns

Type	Description
Promise<LayerView>	Resolves with a LayerView instance.

See also

• Sample - Custom WebGL layer view

destroy()inherited

Since: ArcGIS Maps SDK for JavaScript 4.17

Destroys the layer and any associated resources (including its portalItem, if it is a property on the layer). The layer can no longer be used once it has been destroyed.

The destroyed layer will be removed from its parent object like Map, WebMap, WebScene, Basemap, Ground, or GroupLayer.

See also

• Map.destroy()
• WebMap.destroy()
• WebScene.destroy()
• Basemap.destroy()
• Ground.destroy()
• PortalItem.destroy()

emit(type, event){Boolean}inherited

Since: ArcGIS Maps SDK for JavaScript 4.5

Emits an event on the instance. This method should only be used when creating subclasses of this class.

Parameters

type String The name of the event.

event Object optional The event payload.

Returns

Type	Description
Boolean	true if a listener was notified

fetchImage(extent, width, height, options){Promise<object>}

Fetching the WMS image.

Parameters

Specification

extent Extent The extent of the view.

width Number The width of the view in pixels.

height Number The height of the view in pixels.

options Object optional The parameter options is an object with the following properties. Specification pixelRatio Number optional The ratio of the resolution in physical pixels of the image to the resolution it will be displayed at. rotation Number optional The rotation in degrees of the exported image. signal AbortSignal optional An AbortSignal to abort the request. If canceled, the promise will be rejected with an error named AbortError. See also AbortController.

Returns

Type	Description
Promise<object>	Resolves to an object with the image data.

findSublayerById(id){WMSSublayer}

Returns a WMSSublayer based on the given sublayer id.

Parameter

id Number The id of the WMS sublayer.

Returns

Type	Description
WMSSublayer	Returns the requested IWMSSublayer.

findSublayerByName(name){WMSSublayer}

Since: ArcGIS Maps SDK for JavaScript 4.17

Returns a WMSSublayer based on the given sublayer name.

Parameter

name String The name of the WMS sublayer.

Returns

Type	Description
WMSSublayer	Returns the requested WMSSublayer.

Example

// Display the title and description for the WMS sublayer named "RADAR_1KM_RDBR".
const wmsLayer = new WMSLayer({
  url: "https://geo.weather.gc.ca/geomet"
});
wmsLayer.load().then(() => {
  const subLayer = layer.findSublayerByName("RADAR_1KM_RDBR");
  console.log(`${subLayer.title}`);       // "RADAR - Radar reflectivity (Rain) (1 km) [dBZ]"
  console.log(`${subLayer.description}`); // "Composite of American and Canadian weather radars updated every 10 minutes"
});

hasEventListener(type){Boolean}inherited

Indicates whether there is an event listener on the instance that matches the provided event name.

Parameter

type String The name of the event.

Returns

Type	Description
Boolean	Returns true if the class supports the input event.

hasHandles(groupKey){Boolean}inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Returns true if a named group of handles exist.

Parameter

groupKey * optional A group key.

Returns

Type	Description
Boolean	Returns true if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

isFulfilled(){Boolean}inherited

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). If it is fulfilled, true will be returned.

Returns

Type	Description
Boolean	Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).

isRejected(){Boolean}inherited

isRejected() may be used to verify if creating an instance of the class is rejected. If it is rejected, true will be returned.

Returns

Type	Description
Boolean	Indicates whether creating an instance of the class has been rejected.

isResolved(){Boolean}inherited

isResolved() may be used to verify if creating an instance of the class is resolved. If it is resolved, true will be returned.

Returns

Type	Description
Boolean	Indicates whether creating an instance of the class has been resolved.

load(signal){Promise}inherited

Loads the resources referenced by this class. This method automatically executes for a View and all of the resources it references in Map if the view is constructed with a map instance.

This method must be called by the developer when accessing a resource that will not be loaded in a View.

The load() method only triggers the loading of the resource the first time it is called. The subsequent calls return the same promise.

It's possible to provide a signal to stop being interested into a Loadable instance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad can abort it.

Parameter

signal AbortSignal optional Signal object that can be used to abort the asynchronous task. The returned promise will be rejected with an Error named AbortError when an abort is signaled. See also AbortController for more information on how to construct a controller that can be used to deliver abort signals.

Returns

Type	Description
Promise	Resolves when the resources have loaded.

on(type, listener){Object}inherited

Registers an event handler on the instance. Call this method to hook an event with a listener.

Parameters

type String|String[] An event or an array of events to listen for.

listener Function The function to call when the event fires.

Returns

Type	Description
Object	Returns an event handler with a remove() method that should be called to stop listening for the event(s). Property Type Description remove Function When called, removes the listener from the event.

Example

view.on("click", function(event){
  // event is the event handle returned after the event fires.
  console.log(event.mapPoint);
});

refresh()

Since: ArcGIS Maps SDK for JavaScript 4.6

Fetches all the data for the layer.

See also

• refreshInterval

• refresh event

removeHandles(groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Removes a group of handles owned by the object.

Parameter

groupKey * optional A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

when(callback, errback){Promise}inherited

Since: ArcGIS Maps SDK for JavaScript 4.6

when() may be leveraged once an instance of the class is created. This method takes two input parameters: a callback function and an errback function. The callback executes when the instance of the class loads. The errback executes if the instance of the class fails to load.

Parameters

callback Function optional The function to call when the promise resolves.

errback Function optional The function to execute when the promise fails.

Returns

Type	Description
Promise	Returns a new promise for the result of callback that may be used to chain additional functions.

Example

// Although this example uses MapView, any class instance that is a promise may use when() in the same way
let view = new MapView();
view.when(function(){
  // This function will execute once the promise is resolved
}, function(error){
  // This function will execute if the promise is rejected due to an error
});

Type Definitions

FetchFeatureInfoFunction(query){Promise<Graphic[]>}

Function definition for the fetchFeatureInfoFunction property.

Parameter

query Object An object containing the query parameter names and values.

Returns

Type	Description
Promise<Graphic[]>	Resolves to an array of Graphics.

Event Overview

Event Details

layerview-createinherited

Fires after the layer's LayerView is created and rendered in a view.

Properties

view View The view in which the layerView was created.

layerView LayerView The LayerView rendered in the view representing the layer in layer.

See also

• View.whenLayerView()

Example

// This function will fire each time a layer view is created for this
// particular view.
layer.on("layerview-create", function(event){
  // The LayerView for the layer that emitted this event
  event.layerView;
});

layerview-create-errorinherited

Fires when an error emits during the creation of a LayerView after a layer has been added to the map.

Properties

view View The view that failed to create a layerview for the layer emitting this event.

error Error An error object describing why the layer view failed to create.

See also

• View.whenLayerView()

Example

// This function fires when an error occurs during the creation of the layer's layerview
layer.on("layerview-create-error", function(event) {
  console.error("LayerView failed to create for layer with the id: ", layer.id, " in this view: ", event.view);
});

layerview-destroyinherited

Fires after the layer's LayerView is destroyed and no longer renders in a view.

Properties

view View The view in which the layerView was destroyed.

layerView LayerView The destroyed LayerView representing the layer.

refresh

Since: ArcGIS Maps SDK for JavaScript 4.21

Fires if the layer has the refreshInterval set or when refresh() method is called. The event payload indicates if the layer's data has changed.

Property

dataChanged Boolean Indicates if the layer's data has changed.

See also

• refreshInterval

• refresh()

Example

// listen to layer's refresh event to fetch the attachments
// for the updated features.
layer.on("refresh", function(event){
  if (event.dataChanged){
    const query = layer.createQuery();
    layer.queryObjectIds(query).then(function (objectIds) {
      let attachmentQuery = {
        objectIds: objectIds,
        definitionExpression: layer.definitionExpression,
        attachmentTypes: ["image/jpeg"]
      };
      layer.queryAttachments(attachmentQuery).then(function (attachments) {
        attachmentQuery.objectIds.forEach(function (objectId) {
          if (attachments[objectId]) {
            // process the updated attachments
            let attachment = attachments[objectId];
          }
        });
      })
      .catch(function (error) {
        console.log("attachment query error", error);
      });
    });
  }
});