ArcGIS Services
Last updated
Last updated
SeaSketch supports the addition of layers backed by ArcGIS Services hosted on their server product or ArcGIS Online. For raster layers, SeaSketch requests image tiles from the service. For vector layers, SeaSketch fetches vector data from the service and translates Esri cartographic style to mapbox-gl-style dynamically, and attempts to match this style with maximum fidelity.
To add an Esri service, choose Edit > Add Data > Esri ArcGIS Service. This will open the service search prompt.
SeaSketch remembers recently used servers so that you may quickly add new layers from known locations. The service location you enter must be an ArcGIS REST API service url. This may be a link to the root of a service directory, or a deep link directly to a MapServer or FeatureServer. These urls can typically be identified when they contain /arcgis/rest/services.
After providing a valid location, you will be presented with a catalog viewer where you can see all layers contained in the service. Clicking on a layer will bring up a map preview and an option to add the service to your project. Adding a service will not close the window. Instead, you can browse to find all the layers that you would like to include in your SeaSketch project and add them quickly, one-by-one.
When adding a service to your project, you will need to wait for SeaSketch to evaluate the service. SeaSketch examines layer metadata, cartography, and data size and complexity in order to make a determination about how to best present the layer in SeaSketch. This process may require some time to complete for very complex data sources, but don't worry. When the layer is loaded in SeaSketch and presented to end users it will use information gathered as part of this process to load much more quickly.
SeaSketch is committed to supporting ArcGIS services with high reliability and fidelity, but we need your help! If a service isn't loading for you, or the style doesn't match what is displayed on ArcGIS Online, contact support. Please include a description of the problem and a direct URL for the service in question. The more feedback we have from Esri users, the better we can make this integration.
When importing a tiled map service you will be given the option to import it either as a Basemap or an Overlay Layer. Basemaps are accessible from the Maps sidebar, and can only be viewed one at a time. Overlays can be displayed along with many other layers and their opacity can be changed. Only tiled map services can be imported this way.
SeaSketch gathers cartographic styling information from the underlying service and attempts to faithfully render the data similarly to how it would be displayed on ArcGIS Online. SeaSketch cartography tools are not available for ArcGIS Services. If you would like to style data within SeaSketch, convert the ArcGIS service to a SeaSketch-hosted layer.
Within the layer editor you have short list of available settings for ArcGIS services.
Like uploaded layers, you may enable data download for ArcGIS vector layers supported by a FeatureService or vector FeatureLayer. SeaSketch will extract vector data from the service and provide it to the users as GeoJSON when requested. Data download is not supported for raster services.
When first analyzing a service for inclusion in SeaSketch the fetch strategy will be determined. SeaSketch can either instruct clients to download the entire vector data source in order to display it on the map, or make tiled requests of vector data generalized as appropriate for the given viewport and zoom level. Usually this setting should be left for SeaSketch to determine automatically.
The Data Source tab within the layer editor has a Convert to Hosted Layer button which will harvest vector data from an ArcGIS Service and convert it to a SeaSketch-hosted layer with all the same functionality supported for Uploaded Layers. This is a great option if the original source service is slow, unreliable, or you want to utilize SeaSketch's advanced cartography tools.
Note that converted layers are managed by the data source versioning system. The relation to the old service will be recorded, as well as the requester and date when the conversion took place. Any admin can rollback the layer to the original service. The opens up two interesting capabilities.
It is very easy to evaluate converting a layer to SeaSketch-hosted vs using the originating service.
If data in an ArcGIS service changes, a SeaSketch-hosted service can be rolled back temporarily and then converted again to a hosted service in order to incorporate changes in the service.
Services which contain very large datasets or are generally slow or unreliable may fail the export process when attempting to convert to a hosted service. In these cases it may be easier to contact the data provider for a hard copy of the data.
