Property Overview

Property Details

declaredClass Stringreadonly inherited

Since: ArcGIS API for JavaScript 4.7

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

effect FeatureEffectautocast

Since: ArcGIS API for JavaScript 4.11

The effect applied to the layer view. The effect allows for the selection of features via a filter, and an includedEffect and excludedEffect are applied to those features that respectively pass or fail the filter requirements.

Example:

// set effect on excluded features
// make them gray and transparent
layerView.effect = {
  filter: { // autocasts to FeatureFilter
    geometry: filterGeometry,
    spatialRelationship: geometryRel,
    distance: 3,
    units: "miles"
  },
  excludedEffect: "grayscale(100%) opacity(30%)"
}

filter FeatureFilterautocast

Since: ArcGIS API for JavaScript 4.11

The attribute, geometry, and time extent filter. Only the features that satisfy the filter are displayed on the view.

Example:

// display earthquakes that have
// magnitude value of 3 or higher
layerView.filter = {
  where: "mag >= 3",
};

layer Layerreadonly inherited

The layer being viewed.

maximumNumberOfFeatures Number

Since: ArcGIS API for JavaScript 4.10

The maximum number of features that can be displayed at a time. This setting currently only applies to SceneView. By default, the maximum number of features is estimated automatically depending on the symbology, geometry complexity, memory consumption and display quality profile.

Changing this setting to a higher value may lead to a significant decrease in performance and increase in memory usage.

maximumNumberOfFeaturesExceeded Boolean

Since: ArcGIS API for JavaScript 4.10

Signifies whether the maximum number of features has been exceeded. Not all features could be displayed when this value is true. This setting currently only applies to SceneView.

suspended Booleanreadonly inherited

Value is true if the layer is suspended (i.e., layer will not redraw or update itself when the extent changes).

updating Booleanreadonly inherited

Value is true when the layer is updating; for example, if it is in the process of fetching data.

Default Value:false

visible Boolean inherited

When true, the layer is visible in the view. Set this property to false to hide the layer from the view.

Default Value:true

Method Overview

Method Details

createQuery(){Query}

Since: ArcGIS API for JavaScript 4.12

Creates a query parameter object that can be used to fetch features as they are being displayed. It sets the query parameter's outFields property to ["*"] and returnGeometry to true. The output spatial reference outSpatialReference is set to the spatial reference of the view. Parameters of the filter currently applied to the layerview are also incorporated in the returned query object. The results will include geometries of features and values for all fields.

Returns:

Type	Description
Query	The query object

Example:

const query = csvLayerView.createQuery();
query.where = "magnitude > 4";
csvLayerView.queryFeatures(query).then(function(results) {
  console.log(results);
})
.catch(function(error) {
  console.log(error);
});

highlight(target){Handle}

Highlights the given feature(s).

Parameter:

target Graphic|Graphic[]|Number|Number[] optional The feature(s) to highlight. When passing a graphic or array of graphics, each feature must have a valid objectID. You may alternatively pass one or more objectIDs as a single number or an array.

Returns:

Type	Description
Handle	Returns a highlight handler with a remove() method that can be called to remove the highlight.

See also:

• SceneView.highlightOptions
• MapView.highlightOptions

• Sample: Highlight point features

Examples:

// highlight features based on a query result
var highlight;
view.whenLayerView(treesLayer).then(function(layerView){
 var query = treesLayer.createQuery();
 query.where = "type = 'Quercus'";
 treesLayer.queryFeatures(query).then(function(result){
   if (highlight) {
     highlight.remove();
   }
   highlight = layerView.highlight(result.features);
 })
});

// highlight feature on pointer-move
view.on("pointer-move", function(event){
  view.hitTest(event).then(function(response){
    if (response.results.length) {
      var graphic = response.results.filter(function (result) {
        return result.graphic.layer === treesLayer;
      })[0].graphic;

     view.whenLayerView(graphic.layer).then(function(layerView){
       layerView.highlight(graphic);
     });
    }
  });
});

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.

queryExtent(query, options){Promise<Object>}

Executes a Query against features available for drawing in the layer view and returns the Extent of features that satisfy the query.

Known Limitations

• Spatial queries have the same limitations as those listed in the projection engine documentation.
• Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:
  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore

Parameters:

query Query autocast optional Autocasts from Object Specifies the attributes and spatial filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

options Object optional An object with the following properties. Specification: 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<Object>	When resolved, returns the extent and count of the features that satisfy the input query. See the object specification table below for details. Property Type Description count Number The number of features that satisfy the input query. extent Extent The extent of the features that satisfy the query.

Examples:

var layer = new CSVLayer({
  url: csvUrl  // URL to a csv file
});

view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(val){
    if(!val){  // wait for the layer view to finish updating
      layerView.queryExtent().then(function(results){
        view.goTo(results.extent);  // go to the extent of all the graphics in the layer view
      });
    }
  });
});

// Expand the extent so that a feature (i.e. point feature)
// won't be off screen after the end of goTo animation.
layerView.queryExtent()
 .then(function(result) {
   const zoomScale = 16000;
   const extent = result.extent;

   extent.expand((zoomScale / view.scale) * view.resolution);
   view.goTo(extent);
});

queryFeatureCount(query, options){Promise<Number>}

Executes a Query against features available for drawing in the layer view and returns the number of features that satisfy the query. If query parameters are not provided, the count of all features available for drawing is returned.

Known Limitations

• Spatial queries have the same limitations as those listed in the projection engine documentation.
• Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:
  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore

Parameters:

query Query autocast optional Autocasts from Object Specifies the attributes and spatial filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

options Object optional An object with the following properties. Specification: 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<Number>	When resolved, returns the number of features satisfying the query.

Examples:

view.on("click", function(event){

  var query = new Query();
  query.geometry = event.mapPoint;  // obtained from a view click event
  query.spatialRelationship = "intersects";

  view.whenLayerView(layer).then(function(layerView){
    watchUtils.whenNotOnce(layerView, "updating")
    .then(function(){
      return layerView.queryFeatureCount(query);
    })
    .then(function(count){
      console.log(count);  // prints the number of the client-side graphics that satisfy the query
    });
  });
});

view.whenLayerView(layer).then(function(layerView){
  return layerView.queryFeatureCount()
}).then(function(count){
  console.log(count);  // prints the total number of client-side graphics to the console
});

queryFeatures(query, options){Promise<FeatureSet>}

Executes a Query against features available for drawing in the layer view and returns a FeatureSet. If query parameters are not provided, all features available for drawing are returned.

Known Limitations

• Attribute values used in attribute queries executed against layer views are case sensitive.
• Spatial queries have the same limitations as those listed in the projection engine documentation.
• Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:
  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore

Parameters:

query Query autocast optional Autocasts from Object Specifies the attributes and spatial filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

options Object optional An object with the following properties. Specification: 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<FeatureSet>	When resolved, a FeatureSet containing an array of graphic features is returned.

Examples:

view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(val){
    if(!val){  // wait for the layer view to finish updating
      layerView.queryFeatures(query).then(function(results){
        console.log(results.features);  // prints the array of client-side graphics to the console
      });
    }
  });
});

// returns all the graphics from the layer view
view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(val){
    if(!val){  // wait for the layer view to finish updating
      layerView.queryFeatures().then(function(results){
        console.log(results.features);  // prints all the client-side graphics to the console
      });
    }
  });
});

layerView.queryFeatures({
  geometry: mapPoint,
  // 6 pixels around a point at the view resolution to query around a finger.
  distance: view.resolution * 6,
});

queryObjectIds(query, options){Promise<Number[]>}

Executes a Query against features available for drawing in the layer view and returns array of the ObjectIDs of features that satisfy the input query. If query parameters are not provided, the ObjectIDs of all features available for drawing are returned.

Known Limitations

• Spatial queries have the same limitations as those listed in the projection engine documentation.
• Spatial queries are not currently supported if the layer view has any of the following SpatialReferences:
  • GDM 2000 (4742) – Malaysia
  • Gusterberg (Ferro) (8042) – Austria/Czech Republic
  • ISN2016 (8086) - Iceland
  • SVY21 (4757) - Singapore

Parameters:

query Query autocast optional Autocasts from Object Specifies the attributes and spatial filter of the query. When no parameters are passed to this method, all features in the client are returned. To only return features visible in the view, set the geometry parameter in the query object to the view's extent.

options Object optional An object with the following properties. Specification: 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<Number[]>	When resolved, returns an array of numbers representing the ObjectIDs of the features satisfying the query.

Examples:

view.on("click", function(event){

  var query = new Query();
  query.geometry = event.mapPoint;  // obtained from a view click event
  query.spatialRelationship = "intersects";

  view.whenLayerView(layer).then(function(layerView){
    watchUtils.whenNotOnce(layerView, "updating")
    .then(function(){
      return layerView.queryObjectIds(query);
    })
    .then(function(ids){
      console.log(ids);  // prints the ids of the client-side graphics to the console
    });
  });
});

// returns all the Ids from the graphics in the layer view
view.whenLayerView(layer).then(function(layerView){
  return layerView.queryObjectIds()
}).then(function(ids){
  console.log(ids);  // prints the ids of all the client-side graphics to the console
});

when(callback, errback){Promise}inherited

Since: ArcGIS API 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 then() in the same way
var 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
});