GeoJSONLayerView

Class: esri/views/layers/GeoJSONLayerView
Inheritance: GeoJSONLayerView LayerView Accessor
Since: ArcGIS API for JavaScript 4.11

Represents the LayerView of a GeoJSONLayer after it has been added to a Map in either a MapView or SceneView. The GeoJSONLayerView is responsible for rendering a GeoJSONLayer's features as graphics in the View.

See also

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
Show inherited properties Hide inherited properties
Name Type Summary Class
String[]

A list of attribute fields fetched for each feature including fields required for layer rendering, labeling, elevation info, and additional fields defined on the GeoJSONLayer.outFields.

more details
GeoJSONLayerView
String

The name of the class.

more details
Accessor
FeatureEffect

The featureEffect can be used to draw attention features of interest.

more details
GeoJSONLayerView
FeatureFilter

The attribute, geometry, and time extent filter.

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GeoJSONLayerView
Layer

The layer being viewed.

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LayerView
Number

The maximum number of features that can be displayed at a time.

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GeoJSONLayerView
Boolean

Signifies whether the maximum number of features has been exceeded.

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GeoJSONLayerView
Boolean

Indicates if the spatialReference of the MapView is supported by the layer view.

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LayerView
Boolean

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

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LayerView
Boolean

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

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LayerView
Boolean

When true, the layer is visible in the view.

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LayerView

Property Details

availableFields String[]readonly
Since: ArcGIS API for JavaScript 4.15

A list of attribute fields fetched for each feature including fields required for layer rendering, labeling, elevation info, and additional fields defined on the GeoJSONLayer.outFields. The availableFields property is populated when the layerView has finished updating. The availableFields is used when filtering or querying features on the client-side.

See also
Example
view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(value){
    // availableFields will become available
    // once the layerView finishes updating
    if (!value) {
       layerView.queryFeatures({
         outFields: layerView.availableFields,
         where: "magnitude > 6"
       })
       .then(function(results) {
         console.log(results.features.length, " features returned");
       })
       .catch(function(error) {
         console.log("query failed: ", error);
       });
     }
  });
});
declaredClass Stringreadonly inherited

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

featureEffect FeatureEffectautocast
Since: ArcGIS API for JavaScript 4.22

The featureEffect can be used to draw attention features of interest. It 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.

If the featureEffect is set on the layer, it will be inherited by layerView.featureEffect unless the developer overrides it on the layerView. The layerView.featureEffect will take precedence over layer.featureEffect if both properties are set.

Known Limitations

See also
Examples
// gray out features that fall outside of the 3 mile buffer of the mouse's location
// by setting feature effect on excluded features
layerView.featureEffect = new FeatureEffect({
  filter: new FeatureFilter({
    geometry: filterGeometry,
    spatialRelationship: "intersects",
    distance: 3,
    units: "miles"
  }),
  excludedEffect: "grayscale(100%) opacity(30%)"
});
// Apply a drop-shadow feature effect to the features that intersect the borough boundaries,
// while applying blur and brightness effects to the features that are excluded from filter criteria.
// The resulting map will make it easier to spot if the residents are more likely to experience deprivation
// if they live on a borough boundary.
const featureFilter = new FeatureFilter({
  where: "BoroughEdge='true'"
});
layerView.featureEffect = new FeatureEffect({
  filter: featureFilter,
  includedEffect: "drop-shadow(3px, 3px, 3px, black)",
  excludedEffect: "blur(1px) brightness(65%)"
});

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

See also
Example
// display earthquakes that have
// magnitude value of 3 or higher
layerView.filter = new FeatureFilter({
  where: "mag >= 3",
});
layer Layerreadonly inherited

The layer being viewed.

maximumNumberOfFeatures Number

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.

Known Limitations

The maximumNumberOfFeatures is only supported in 3D SceneViews.

maximumNumberOfFeaturesExceeded Boolean

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.

Known Limitations

The maximumNumberOfFeaturesExceeded is only supported in 3D SceneViews.

spatialReferenceSupported Booleanreadonly inherited
Since: ArcGIS API for JavaScript 4.23

Indicates if the spatialReference of the MapView is supported by the layer view. When false layer view will be suspended.

See also
suspended Booleanreadonly inherited

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

See also
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. Value of this property is inherited from the layer.visible unless the developer overrides it. The layerView.visible will take precedence over layer.visible if both properties are set.

Default Value:true

Method Overview

Show inherited methods Hide inherited methods
Name Return Type Summary Class

Adds one or more handles which are to be tied to the lifecycle of the object.

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Accessor
Query

Creates query parameter object that can be used to fetch aggregate features as they are being displayed.

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GeoJSONLayerView
Query

Creates a query parameter object that can be used to fetch features as they are being displayed.

more details
GeoJSONLayerView
Boolean

Returns true if a named group of handles exist.

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Accessor
Handle

Highlights the given feature(s).

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GeoJSONLayerView
Boolean

isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).

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LayerView
Boolean

isRejected() may be used to verify if creating an instance of the class is rejected.

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LayerView
Boolean

isResolved() may be used to verify if creating an instance of the class is resolved.

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LayerView
Promise<FeatureSet>

Executes a Query against aggregate features (i.e.

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GeoJSONLayerView
Promise<object>

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

more details
GeoJSONLayerView
Promise<number>

Executes a Query against features available for drawing in the layerView and returns the number of features that satisfy the query.

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GeoJSONLayerView
Promise<FeatureSet>

Executes a Query against features available for drawing in the layerView and returns a FeatureSet.

more details
GeoJSONLayerView
Promise<number[]>

Executes a Query against features available for drawing in the layerView and returns array of the ObjectIDs of features that satisfy the input query.

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GeoJSONLayerView

Removes a group of handles owned by the object.

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Accessor
Promise

when() may be leveraged once an instance of the class is created.

more details
LayerView

Method Details

addHandles(handleOrHandles, groupKey)inherited
Since: ArcGIS API 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 }
);

// Handle gets removed when the object is destroyed.
this.addHandles(handle);
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.

createAggregateQuery(){Query}
Since: ArcGIS API for JavaScript 4.25

Creates query parameter object that can be used to fetch aggregate 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.

Returns
Type Description
Query The query parameter object.
See also
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 = layerView.createQuery();
query.where = "magnitude > 4";
layerView.queryFeatures(query).then(function(results) {
  console.log(results);
})
.catch(function() {
  console.log(error);
});
hasHandles(groupKey){Boolean}inherited
Since: ArcGIS API 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");
}
highlight(target){Handle}

Highlights the given feature(s).

Parameter
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
Examples
// highlight features based on a query result
let highlight;
view.whenLayerView(treesLayer).then(function(layerView){
 let 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) {
      let 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.
queryAggregates(query, options){Promise<FeatureSet>}
Since: ArcGIS API for JavaScript 4.25

Executes a Query against aggregate features (i.e. clusters or bins) available for drawing in the layerView and returns a FeatureSet. If query parameters are not provided, all aggregates available for drawing are returned along with their attributes that are available on the client. Fields referenced in statistic queries or in the where clause must first be defined as aggregate fields.

Known Limitations

This method currently does not support spatial queries (i.e. the Query.geometry option and its related properties).

Parameters
query Query autocast
optional
Autocasts from Object

Specifies the parameters of the query. Leave this parameter empty to query all aggregates in the view.

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, returns a FeatureSet containing an array of aggregate features.
See also
Example
// clustered point layer
const layer = new GeoJSONLayer({
  featureReduction: { type: "cluster" }
});

const layerView = await view.whenLayerView(layer);

layerView.watch("updating", async (val) => {
  if(!val){  // wait for the layer view to finish updating
    const { features } = await layerView.queryAggregates();
    // features represents all the clusters in the view
  }
});
queryExtent(query, options){Promise<object>}

Executes a Query against features available for drawing in the layerView 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 layerView 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
let layer = new GeoJSONLayer({
  url: geoJSONUrl  // URL to a geoJSON file
});

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

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

  view.whenLayerView(layer).then(function(layerView){
    reactiveUtils.whenOnce(() => !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 layerView 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 layerViews 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 layerView 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.
See also
Examples
view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(val){
    if(!val){  // wait for the layerView 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 layerView
view.whenLayerView(layer).then(function(layerView){
  layerView.watch("updating", function(val){
    if(!val){  // wait for the layerView 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 layerView 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 layerView 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){

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

  view.whenLayerView(layer).then(function(layerView){
    reactiveUtils.whenOnce(() => !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 layerView
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
});
removeHandles(groupKey)inherited
Since: ArcGIS API 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

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
});

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