Understand data sources

Dashboards contain many data-driven elements such as maps, charts, lists, gauges, panels, and selectors. The data sources used to power these elements come from layers stored in your organization, either as web layers or operational layers in web maps, or from feature sets generated with data expressions.

Note:

Web scenes are not currently supported.

Web layers and web maps

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) and Microsoft Excel files, or open standards based, such as KML. Other data sources are native to ArcGIS, such as hosted layers and ArcGIS Server services.

A dashboard's elements work with feature-based layers. In particular, dashboard elements work with map service layers, feature service layers, and feature collections. To determine whether a web 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.

All data-driven elements (except the map element), such as list, serial chart, pie chart, and indicator, are directly based on these layers or are powered by a data expression. The data source for the map element is a web map, which can contain various types of web layers. The following are examples of data sources that can be viewed in a dashboard map but not 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.

When a web map has been added to a dashboard through a map element, all of its supported operational layers can be used to supply data to other elements in the dashboard. See Create web maps for dashboards for best practices on authoring web maps to use in Dashboards.

Caution:

Once other elements use a web map's operational layers, deleting a map element from the dashboard produces a warning that dependent elements will also be deleted.

Data expressions

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 executed within 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 they are created in. They are not stored in your organization's content as items. To use the same data expression in another dashboard, you need to re-create the expression in that dashboard.

Tip:

You can use the same data expression in multiple elements on the same dashboard. When possible, re-use data expressions across elements.

Note:

Before creating a data expression, read the recommended best practices for creating data expressions.

Layer capabilities

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 candidate layers have equal capabilities.

Note:

Layers that are not candidates will 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 check 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 checks 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:

Layer filters

Any filters applied to a web map's operational layer or 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.