In the previous release of ArcGIS Online, we introduced the concept of hosted feature layer views. These allow you to create multiple views, each with different editing capabilities and styling, all while leveraging the same underlying data. With this release, hosted feature layer views have gotten even better. In addition to being able to adjust the styling, sharing, and editing permissions, you can now define what data is visible on your view by creating a view definition, either by using a feature definition (allowing you to only show features that match a query) or by controlling what fields are visible in the view. Unlike the popup and other existing filters, these new definition settings will restrict access to the data even when you are working directly with the layer over REST (as a developer) or when users are exporting the data to different formats.
The example outlined in my previous blog article on the different uses of feature layer views shows where this functionality really shines. You can create a view for the public to see coyote sightings while restricting that view to show data that has been reviewed by city staff, or you can only show sightings to your field staff that are recent (say within the last 6 months).
Now, using view definitions, you can also hide fields that are not relevant to the public and are used solely within your organization for good data management processes. This makes your public awareness web app even more concise. It doesn’t have to stop there, though. You could also make that data available through your organization’s Open Data portal, and allow developers and members of the public to download the information and use it to do further analysis, or when building their own location-aware apps—for example, a user might get an alert if they are in the vicinity of a recent coyote sighting.
Hosted feature layer views are really about giving you the power to control how your data is viewed and consumed, without having to duplicate data and introduce additional complexity to the management of your data. View definitions are a powerful new enhancement to feature layer views, but to ensure they are used effectively, there are a couple of important details you should note. If you have to add a field to your primary feature layer and want that field to show up for a particular view you have already created, you must update the definition of the view to include that field as visible as it will not be automatically enabled on the view. Also if you remove a field from a view be sure to take the time to update your existing popups to reflect the change for the best experience. For definitions to function properly, your organization must have the Allow only standard SQL queries security setting enabled. Most users will already have this setting enabled in their organization as part of their security best practices. This setting is essential in helping to prevent SQL injection attacks and will also prevent any unexpected results when performing queries against the data that make use of hidden fields.
Make sure you take the time to leverage the functionality and flexibility of hosted feature layer views when delivering great maps, apps and data to your users. Whether that’s within your organization or whether you are empowering and informing the public through your work. To find even more information about hosted feature layer views, head over to our help topic for more information.