The Living Atlas Environment Team uses hosted feature layers for many of the information products that we create. These layers serve as the foundational building blocks for maps, applications and geospatial analysis.

We use both ArcGIS Online and ArcGIS Pro to publish hosted feature layers. The workflow that we choose depends on the complexity of the dataset and symbology as well as the expected update frequency.

This blog will discuss publishing hosted feature layers in ArcGIS Online. We will cover publishing from ArcGIS Pro in an upcoming blog.

What is a hosted feature layer?

At the most basic level a hosted feature layer is a layer created from a vector dataset that is stored and served from ArcGIS online. A feature layer can be used throughout the ArcGIS platform for visualization and analysis.

With hosted feature layers you can work directly with the data to filter, select, symbolize and much more. Hosted feature layers can be used as geoprocessing inputs and are easy to create, reliable, and perform well. Because they don’t require a server, hosted feature services are an excellent choice for smaller organizations that may lack the resources necessary to manage a server while enabling ability to publish large, complicated datasets.

ArcGIS Online

This application uses the USA Flood Hazard Areas hosted feature layer. The layer was published in ArcGIS Online and is updated biennially. The symbology is straightforward and is saved in the layer item along with the pop-up configuration.

Publishing and updating a hosted feature layer from ArcGIS Online is easy and straightforward but there are several things to consider.

Because the ArcGIS Online publishing process involves uploading a vector data file, the symbology, pop-up and other configuration settings must be saved to the hosted feature layer’s item. To do this open the layer in the online map viewer, symbolize the layer and then save the layer by clicking More Options > Save Layer next to the layer in the table of contents. Note that this is different than using the Save button at the top of the map that saves a webmap.

The benefit of saving configurations to the hosted feature layer’s item is that when a user creates a map or application settings saved to the layer’s item will be automatically applied. Settings saved at the webmap level are only applied to the webmap and applications created using the webmap. By setting the properties on the feature layer you are creating a ready-to-use information product that others can use successfully.

When updating hosted feature layers using the Update Data > Overwrite Entire Layer option the layer’s symbology, pop-up configuration and other settings that are saved to the layer’s item are preserved. This facilitates updating the data behind the service without disrupting important settings.

Why can’t I see the Overwrite Entire Layer option?

If certain conditions are not met the Overwrite Entire Layer option won’t appear under Update Data and only Append to Data will be available.

To be updated in ArcGIS Online a layer must be published from ArcGIS Online. The Overwrite Entire Layer option won’t be available under Update Data if published from ArcGIS Pro. Other reasons that the Overwrite Entire Layer option won’t appear is if the editing settings sync functionality or tracking created and updated features are enabled on the layer.

Files should match

To ensure that maps and applications that use the feature layer are not broken, the new file must match the file being overwritten. Values that should match include:

• File Type
• File Name
• Feature Class Names
• Schema
• Field Order
• Field Names
• Field Type

Remember that overwriting the layer both from ArcGIS Online or Pro disables layer optimization. This setting is very useful when working with layers containing large numbers of features and/or vertices.

For more information on the settings available on hosted feature services see Manage Hosted Features on the ArcGIS Online help page.

Part 2 of this blog is now available at: Pro or Online? Part 2: Publishing Hosted Feature Layers from ArcGIS Pro