LayerStructure class—ArcGIS Web AppBuilder

The LayerStructure class reflects the structure of the operational layers in the current map. It is used to traverse and operate each layer and sublayer abstracted as a LayerNode in the LayerStructure.

AMD Module Require

require(["jimu/LayerStructure"], function(LayerStructure) { /* code goes here */ });

Constructor

There is a single instance of LayerStructure in the Web AppBuilder environment. var layerStructureInstance = LayerStructure.getInstance(); Example: Prints the tree structure of the operational layers in the current map in the console window. `var layerStructure = LayerStructure.getInstance(); function printLayerTree() { layerStructure.traversal(function(layerNode) { var indent = ""; for(var i = 0; i < layerNode.getNodeLevel(); i++) {indent += " ";} console.log(indent, layerNode.title); }); } printLayerTree(); layerStructure.on(LayerStructure.EVENT_STRUCTURE_CHANGE, function(eventObject) { // reprint the layer tree if the layer structure has been changed; printLayerTree(); });`

There is a single instance of LayerStructure in the Web AppBuilder environment.

var layerStructureInstance = LayerStructure.getInstance();

Example:

Prints the tree structure of the operational layers in the current map in the console window.

var layerStructure = LayerStructure.getInstance();
        function printLayerTree() {
          layerStructure.traversal(function(layerNode) {
            var indent = "";
            for(var i = 0; i < layerNode.getNodeLevel(); i++) {indent += "  ";}
            console.log(indent, layerNode.title);
          });
        }

        printLayerTree();

        layerStructure.on(LayerStructure.EVENT_STRUCTURE_CHANGE, function(eventObject) {
          // reprint the layer tree if the layer structure has been changed;
          printLayerTree();
        });

Constants


STRUCTURE_CHANGE_ADD	Type of structure change event when layerNodes are added.
STRUCTURE_CHANGE_REMOVE	Type of structure change event when layerNodes are removed.
STRUCTURE_CHANGE_SUBNODE_ADD	Type of structure change event when subLayerNodes are added.
STRUCTURE_CHANGE_SUBNODE_REMOVE	Type of structure change event when subLayerNodes are removed.
STRUCTURE_CHANGE_NODE_UPDATE	Type of structure change event when layerNodes are updated.
STRUCTURE_CHANGE_REORDER	Type of structure change event when layerNodes are reordered.
EVENT_STRUCTURE_CHANGE	Event name for a structure change.
EVENT_TOGGLE_CHANGE	Event name for a toggle change.
EVENT_VISIBILITY_CHANGE	Event name for a visibility change.
EVENT_FILTER_CHANGE	Event name for a filter change.
EVENT_RENDERER_CHANGE	Event name for a renderer change.
EVENT_OPACITY_CHANGE	Event name for an opacity change.

Methods

addTable(table) Adds a table to layerStructure. Parameters: `table = { id: Optional parameters, title: title of new table, url: alternative with featureCollectionData, featureCollectionData: alternative with url, options: Optional parameters. See options list of FeatureLayer Constructor from ArcGIS JavaScript API reference. }` Return value: LayerNode

addTable(table)

Adds a table to layerStructure.

Parameters:

  table = {
      id: Optional parameters,
      title: title of new table,
      url: alternative with featureCollectionData,
      featureCollectionData: alternative with url,
      options: Optional parameters. See options list of FeatureLayer Constructor from
               ArcGIS JavaScript API reference.
  }

Return value: LayerNode


getBasemapLayerObjects() Gets the layerObjects from the basemap. Parameters: null Return value: LayerObject[]


getLayerNodes() Gets the operational layerNodes in the current map. Parameters: null Return value: LayerNode[]


getNodeById(nodeId) Gets the layerNode or tableNode by ID. Parameters: nodeId—layerNode or tableNode Id. Return value: LayerNode


getTableNodes() Gets the operational tableNodes in the current map. Parameters: null Return value: LayerNode[]


getWebmapLayerNodes() Gets the operational layerNodes that are defined in the web map. Parameters: null Return value: LayerNode[]


getWebmapTableNodes() Gets the operational tableNodes that are defined in the web map. Parameters: null Return value: LayerNode[]


removeTable(nodeId) Removes a tableNode from layerStructure by the node ID. Parameters: nodeId—The tableNode ID. Return value: null


traversal: function(callback) Traverses all nodes of the layerStructure with Depth-First-Search. Parameters: callback: function(layerNode) {}; Callback parameters: layerNode Callback return value: Boolean—Returns true when the traversal is interrupted; returns false when the traversal continues. Return value: Boolean—Returns true when the traversal is interrupted; returns false when the traversal is complete.


traversalWithNodes: function(callback, nodes) Traverses all nodes of nodes parameter with Depth-First-Search. Parameters: callback: function(layerNode) {}; Callback parameters: layerNode Callback return value: Boolean— Returns true when the traversal is interrupted; returns false when the traversal continues. nodes—The layerNodes array Return value: Boolean—Returns true when the traversal is interrupted; returns false when the traversal is complete.

Events


structure-change Fires when the structure is changed. Event object: `{ type: String layerNodes: LayerNode[] rootLayerNodes: LayerNode[] }` See also: EVENT_STRUCTURE_CHANGE in the Constants table.


toggle-change Fires when the layerNodes toggle is changed. Event object: `{ layerNodes: LayerNode[] }` See also: EVENT_TOGGLE_CHANGE in the Constants table


visibility-change Fires when the visibility of layerNodes is changed. Event object: `{ layerNodes: LayerNode[] }` See also: EVENT_TOGGLE_CHANGE in the Constants table.


filter-change Fires when the layerNodes filter is changed. Event object: `{ layerNodes: LayerNode[] }` See also: EVENT_FILTER_CHANGE in the Constants table.


renderer-change Fires when the layerNodes renderer is changed. Event object: `{ layerNodes: LayerNode[] }` See also: EVENT_RENDERER_CHANGE in the Constants table.


opacity-change Fires when the layerNodes opacity is changed. Event object: `{ layerNodes: LayerNode[] }` See also: EVENT_OPACITY_CHANGE in the Constants table.

ArcGIS Web AppBuilder

AMD Module Require

Constructor

Constants

Methods

Events

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