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.
To use a hosted feature layer (spatiotemporal), the map image layer and the feature layer must be shared in the same manner. For example, if you are attempting to use a hosted feature layer (spatiotemporal) that has been shared to you through a group, the associated map image layer must also be shared to the same group.
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. Use these variables most commonly in conjunction with a real-time analytic that is continuously writing events to a feature layer output as the events occur. |
QueryString |
|
Out fields |
Loads the fields from the feature layer into Velocity. The default is the asterisk (*), which loads all fields. When specifying fields, use a comma-separated list of field names, for example: |
String |
|
Output spatial reference |
The well-known ID (WKID) of a spatial reference. The default is 4326. |
String |
|
Additional logging (optional) |
Specifies whether Velocity turns on logging for raw requests. The default is False. Note:Turn on this parameter only for troubleshooting, then turn it off when complete. Contact Esri Technical Support for help with troubleshooting. |
Boolean |