Feature Layer

The Feature Layer source type in ArcGIS Velocity loads features from a feature layer.

Examples

The following are example use cases for the data source:

• A user selects a hosted feature layer containing the features to load from ArcGIS Enterprise.

• A GIS analyst provides the URL to an ArcGIS Server feature layer (for example, https://sampleserver6.arcgisonline.com/arcgis/rest/services/Wildfire/FeatureServer/2) containing the features to load.

• A user can add real-time weather conditions to their map by incorporating a weather feature layer from ArcGIS Online.

Usage notes

Keep the following in mind when working with the data source:

• When browsing a feature layer item, you can filter by folders, favorites, groups, or organization. You can filter further by date modified, date created, and tags.

• ArcGIS Server feature layers can also be loaded using a URL. Use an ArcGIS Server services directory REST URL (for example, https://sampleserver6.arcgisonline.com/arcgis/rest/services/Wildfire/FeatureServer/2). This URL should end in /FeatureServer/# or /MapServer/# in which # is the layer number.

• To load a secured feature layer from a URL, first add the items to your organization's portal. and store credentials, then browse to the registered item in your organization's portal to load the secured feature layer.

• Feature layers must have a unique identifier field. The unique identifier must not be null, must contain unique values, and must be one of the following data types:

  • Integer (32- and 64-bit positive values only)

  • String

  • GUID

  • Date

  • Date only

  • Time only

• A timestamp field cannot be specified when configuring a feature layer source in a real-time analytic, because each time the real-time analytic is started, the feature layer feed loads all features returned by the configured where clause.

• After configuring the source connection parameters, refer to configuring input data to learn how to define the schema and the key parameters.

• For optimal polling performance, if available it is recommended to create an attribute (field) index on the Date field for latest features option referenced by the Timestamp field parameter. This improves query efficiency when filtering records between polling intervals. Attribute (field) indexes can only be created on feature layers that are owned or administered by the Velocity user.

Parameters

The following are the parameters for the data source:

Parameter	Description	Data type
WHERE clause	A Structured Query Language (SQL) clause used to filter features loaded from the specified feature layer. The default is to load all features using 1=1 and can be modified to include specific attribute values and logic conditions. Most feature layers support SQL-92 WHERE clause syntax on the fields in the layer The most common workflow for using these variables is in conjunction with a real-time analytic that is continuously writing events to a feature layer output as the events occur. Learn more about near real-time analysis	QueryString
Out fields	The fields from the feature layer that are loaded into Velocity. The default is an asterisk (*), which denotes that all fields are loaded. When specifying fields, use a comma-separated list of field names, for example: device_id,timestamp,horizontal_accuracy,latitude,longitude.	String
Output spatial reference	The well-known ID (WKID) of a spatial reference. The default is 4326.	String
Additional logging (optional)	Specifies whether logging for raw requests issued by Velocity is available. The default is False. Note: Only turn on this parameter for troubleshooting purposes and turn it off when troubleshooting is complete. Contact Esri Technical Support for help with troubleshooting.	Boolean