In ArcGIS, you work with geographic data through layers. In general, there are two data types that can be referenced by a layer: feature and imagery. The data used when displaying a layer comes from various sources. Some data sources are file based, such as comma-separated values (CSV) files, or open standards based, such as KML. Other data sources are native to ArcGIS, such as hosted layers and ArcGIS Server services.
Dashboards contain many data-driven elements such as maps, charts, lists, and gauges. The data sources used to power these elements come from layers in web maps, layers in web scenes, web layers stored in your organization, or feature sets generated with data expressions.
Layers in web maps
Not all layers that are supported in a web map can be used to supply data to other dashboard elements. The following are data sources that can be viewed in a dashboard map element as a result of adding a web map, but cannot be used as a data source for other dashboard elements:
You can also use a CSV file by a referenced URL as a data source in your elements. To use a CSV file by a referenced URL, the web map with the referenced layer must first be added to a dashboard through the map element.
Layers in web scenes
Not all layers that are supported in a web scene can be used to supply data to other dashboard elements. The following are data sources that can be viewed in a dashboard map element as a result of adding a web scene, but cannot be used as a data source for other dashboard elements:
Currently for scene layers, only 3D object scene layers and point scene layers with associated feature layers in a web scene can be used as data sources in dashboard elements.
Data-driven elements, such as lists, serial charts, pie charts, and indicators, work with feature-based layers. In particular, dashboard elements work with map service layers, feature service layers, and feature collections. To determine whether a layer is backed by one of these services, check its item details. Layer items that have a source of Map Service, Feature Service, or Feature Collection can be used as data sources for elements.
When these layers are not coming from a web map or web scene that has been added to the dashboard, they can be added as stand-alone layers.
A data expression is any Arcade expression that returns a FeatureSet. The FeatureSet can be used as data sources for data-driven elements. Your data expressions are authored, saved, and run in ArcGIS Dashboards. Using the Arcade function library, you can author data expressions that unlock new insights by combining, modeling, or enhancing your existing data. You can also take advantage of data you do not own, such as ArcGIS Living Atlas layers.
When you create data expressions, they are only available for the dashboard in which they are created. They are not stored in your organization's content as items. To use the same data expression in another dashboard, you must re-create the expression in that dashboard.
You can use the same data expression in multiple elements on the same dashboard. When possible, reuse data expressions across elements.
Before creating a data expression, read the recommended best practices for creating data expressions.
When a layer is backed by a supported data source, it can be used in a dashboard. You can select it when browsing for data when configuring dashboard elements. However, not all supported layers have equal capabilities.
Layers that are not supported appear while browsing for data in the Select a layer screen, but they cannot be selected.
When selecting a layer to be used in a dashboard, a verification is made to ensure that its underlying service can be queried. This is so design-time and dynamic runtime filters can be applied. Failure to pass this test results in a message that the layer does not meet the necessary criteria to use it in a visual element, and an OK button is enabled so you can choose another layer from the Select a layer screen.
When configuring an element, additional capability verifications can be made, including the following:
- Does the layer support querying using aggregate functions (for example, COUNT, MAX, MIN, SUM, and AVG) to group the result set by one or more columns?
- Does the layer support querying so that the result set can be displayed in ascending or descending order?
- Does the layer support statistics?
- Does the layer have map and data capabilities?
If some of these capabilities are not met, you may experience differences in the dashboard authoring experience. For instance, if the layer meets the necessary query capabilities but not the other capabilities listed above, a warning appears in the Select a layer screen.
Different layers have different capabilities for various reasons, such as the ArcGIS Server version used to create the layer. For more information about candidate services and layers, see the following resources:
Any attribute filters applied to an operational layer in a web map or web scene, or to a web layer, are respected in a dashboard. You can create design-time or runtime filters that can be applied in addition to any predefined filter conditions that may already exist.
Field names and aliases
Field names are those given to the columns in a layer and indicate which data the column contains. Field aliases allow for an alternate name for a field. Whenever a field has an alias defined, Dashboards shows that alias when you are viewing a field, such as when choosing a field for a filter condition, or choosing a field to sort features by in the details or list elements. When an alias is not available, the field name is used.