Wireless connectivity while outside, remains a challenge for mobile users. The discussion of offline ArcGIS, or the ability to use a GIS application without need for a wireless connection, is often focused on working in remote areas. But poor or slow loading ArcGIS apps are all too common in both remote and highly populated areas. Poor wireless signals can lead to almost unusable mobile apps.
Why should all Mobile ArcGIS apps work offline?
It is for that reason we believe that all mobile ArcGIS apps should be offline enabled. Case in point. Last week we were working with Collector for ArcGIS collecting data in downtown Salt Lake City. We were using the app in online mode (Collector is also offline enabled). Loading the app took over 3 minutes, every pan, zoom, update was painfully slow. A task which should have taken an hour, took considerably longer.
In our view all mobile ArcGIS apps should work offline. Collector for ArcGIS and our Universal Map Viewer are among the few ArcGIS apps which provide both full online and offline or disconnected capabilities.
How does offline ArcGIS work?
Offline ArcGIS uses data stored locally on your mobile device, and does not rely on calling ArcGIS over wireless. There are two key parts to offline enabling any ArcGIS app:
1. Download base-map tiles locally. This could be satellite data, roads, topographic or your tiled maps.
2. Download feature layers. These are interactive point, line and polygon layers which can also be edited.
All data is stored in local databases on your mobile device.
In the case of our our Universal Map Viewer, shown above, we have a widget which allows users to download locally basemaps. Tapping the green ‘Online’ button takes the application offline by pointing at this local data.
Why are there so few offline enabled ArcGIS apps
Though on the surface offline enabling an ArcGIS app seems simple, in reality there is much complexity behind the scenes (hidden to users). Many offline enabled mobile apps are native. That means they are written in a language specific for a single mobile platform. That is why you will see apps built for iOS (Apple devices) or Android only. In the case of Collector for ArcGIS, offline enablement took a number of years to develop. The application has 3 versions (and thus 3 development teams) iOS, Android and soon Windows. That is an expensive undertaking.
We took a Web based approach to offline ArcGIS with our Universal Map Viewer. Why? First, our customers wanted a true cross-platform cross-device solution. One which not only can be used on all mobile devices (smartphones, tablets) and platforms (iOS, Android, Windows, Blackberry) but laptops also. Second, we have been frequently asked for functionality which is not in Collector; custom forms, draw and geocoder tools etc. Universal Map Viewer allows custom widgets to be added to a mobile application.
As mobile GIS becomes more popular, we suspect there will be a wave of new offline enabled ArcGIS applications appearing on the market. That is music to the ears of mobile users.