If you’ve used ArcGIS, you’ve likely created a web map at some point. You’ve added layers, selected a basemap, made some configurations then clicked Save. What is being saved, though? What exactly is a web map? ArcGIS Online documentation defines a web map as “an interactive display of geographic information that you can use to tell stories and answer questions”. An excerpt from The ArcGIS Book, Second Edition: 10 Big Ideas about Applying The Science of Where, further describes web maps as “online maps created with ArcGIS that provide a way to work and interact with geographic content organized as layers. They are shared across your organization and beyond on the web and across smartphones and tablets. Each map contains a reference basemap along with a set of additional data layers..”
These descriptions are accurate yet still don’t convey how you’re able to take geographic content organized as a collection of layers and display the content in a consistent manner regardless of the application being used to view the web map. Documentation on the ArcGIS for Developers site makes clear how this happens, defining a web map as “a 2D map that you can create, style, and share between different applications. Web maps are JSON objects defined by the Web Map Specification and contain configuration settings for the map extent, basemap, layers, layer styles, pop-ups and more.” The Esri Web Map Specification is the backbone for providing a consistent experience across multiple applications. When you create a web map in the current Map Viewer, also called Map Viewer (classic), you expect the map to look the same when you use it in a Configurable App, Web AppBuilder, StoryMaps, or any other ArcGIS application. This consistent experience happens because ArcGIS apps can read the web map specification and are committed to displaying web maps as defined in the spec. Furthermore, authoring apps are committed to producing web maps compliant with the web map spec.
Why change how Map Viewer authors web maps?
The ability to author web maps in Map Viewer (classic) was built directly into the app. Building a new Map Viewer using JSAPI 4.x (Map Viewer (classic) uses JSAPI 3.x) meant also rebuilding how maps are authored. This presented an opportunity to consider how the authoring process can be improved under the hood. When the current Map Viewer was first introduced, there weren’t any other applications with the ability to author maps. It was reasonable for the authoring implementation to be wholly contained within Map Viewer itself. Ten years later, many applications are now writing or updating web maps. Without an API that handles the authoring process, applications have been required to build the ability to author web maps themselves (or get creative in how to handle this aspect). In addition to the investment necessary to build the logic for authoring spec-compliant web maps, any deviations from the spec could lead to an inconsistent experience across apps consuming web maps. Adding the ability to author spec-compliant web maps to JSAPI 4.x means apps that require authoring functionality can use the JSAPI rather than building the logic themselves. Aside from saving time for developers, a central authoring component also helps ensure consistent adherence to the web map specification, which in turn means a more consistent and confident experience for users.
Support for web maps authored in Map Viewer Beta
For additional details, see the Combability Guide for web maps created with Map Viewer (classic) and Map Viewer Beta.
Web maps authored in Map Viewer (classic)
Web maps authored in Map Viewer (classic) can be opened and updated in Map Viewer Beta. Furthermore, web maps authored in Map Viewer (classic) and subsequently updated in Map Viewer Beta are supported across the platform. However, in some instances where support has not yet been implemented for certain layer types or for specific functionality, the updated web map may not persist unsupported configurations. For example, if a web map contains a Table layer, the Table layer will not be persisted in the web map when saved in Map Viewer Beta.
In other instances where a layer type or specific configuration is not supported, Map Viewer Beta may not display the layer or configuration, but it is persisted when saving the map in Map Viewer Beta. For example, WFS layers are not currently supported in Map Viewer Beta. If a map with a WFS layer is opened in Map Viewer Beta, the WFS layer is not displayed. However, if the map is saved in Map Viewer Beta, the layer is persisted as it was originally configured.
In general, when opening existing web maps in Map Viewer Beta that were authored in the current Map Viewer (or elsewhere), it is recommended to save as a new map. For more information, refer to the Combability Guide for web maps created with Map Viewer (classic) and Map Viewer Beta.
What does this mean for you?
- For compatibility between Map Viewer Beta and Map Viewer Classic, see Compatibility Guide for Map Viewer (classic) and Map Viewer Beta.
- For more information on features planned for Map Viewer Beta, see the Map Viewer Beta road map.
Questions? Visit us on Geonet and join the conversation.