Recently, I needed to create a map of some publically available datasets in Newark, New Jersey to share with community organizations there. I figured a web map would be the simplest solution, as it allowed exploration of these data without them needing to install software or me having to create dozens of .pdf maps.
Given Esri’s generous credit limits in ArcGIS Online for higher education and their user-friendly web app templates, selecting this platform was an easy choice. The final result looked something like this:
As someone who likes to learn by trial and error, and then Google answers when I run into issues, I hit a few snags along the way stemming from not thinking through what service type to select when publishing my data (i.e., tile service v. feature service; more information on these options is available here). Given that the map needed to have several different layers showing census metrics, I simply published a single census dataset with attribute fields of all the different metrics I was interested in as a feature service. This made it very easy to reference a different attribute field to get all my needed layers on the map (example below):
However, I then could not display features that had to be published as a tile service on top of the census information, resulting in me needing to publish each individual census layer as its own, separate tile service layer.
While the information below is all available across a few resource pages on the Esri website, here are my three biggest takeaway points that I hope may be useful to someone else planning out a web map with a large number of data layers.
1. Tile services will always draw below feature services (regardless of feature type—i.e., point/line/polygon). So if you had a point layer that you published as a tile service and a polygon layer that you published as a feature service, you could not display the tile service points on top of the feature service polygons.
2. Remember that feature services can only display <1,000 features at a time. If you have more than that, you want to create a tile service.
3. Tile services alone won’t have pop-up windows. If you want a tile service with pop-up windows, you’d need to create both a tile service and feature service simultaneously.
So in summary, if we're building a new map with a dozen+ layers that I wanted folks to be able to interact with, I would budget a good 15-30 minutes planning things out, with particular emphasis on what kinds of services I needed first. If you’re planning to use a mix of service types you’d want to ensure that the tile services will display appropriately beneath the feature services.