Continuing the exploration of the ArcGIS Online December 2012 release, Part 2 focuses on enhancements in the areas of publishing, sharing and administration, and printing. The previous post in the series looked at new functionality added to the ArcGIS Online Map Viewer.
As an organisation with an ArcGIS Online subscription, you have the ability to publish maps you create in ArcGIS for Desktop as two different types of service that are then hosted entirely within ArcGIS Online. Before I talk about the changes in this area, let’s just reflect on the difference between the two types of service and why you might use them both. Firstly tiled services – these are the same as the base maps that you can consume from ArcGIS Online like World Imagery or World Street Map – they’re multi-scale maps, pre-rendered at a fixed set of ubiquitous scales, and delivered as 256 x 256 pixel image tiles. That delivery is really fast because there’s no round trip back to the data required – it’s just small images being sent down the wire. In the context of your ArcGIS Online subscription context, the data behind the map is all yours – you’re effectively building your own base map to use as a canvas for other data.
Feature services on the other hand are designed to deliver data on the fly rather than images of the data. When you publish a feature service, in the simplest case, you’re opening up a channel to your data that lets a user query and retrieve that data, and then take control of how the data is displayed. In GIS lingo, the feature service sends geometry and attributes to the client, and the client decides how to render it. This for example is what gives you the ability to change the symbology of features in a web map through the ArcGIS Online Map Viewer. Feature services offer more than that though. Depending on the options set by the publisher, a feature service is also a channel for data travelling in the other direction – data being created dynamically by the users of the web map.
As an example of using both types of service, consider a local government user of ArcGIS Online tasked with standing up a web map for public consumption that covers Local Environmental Plan (LEP) information that is currently under review. Council in this case have crafted a base map in ArcGIS for Desktop that is a common canvas for many other maps within the organisation. The map has a bunch of layers of data that are pretty static, and GIS professionals within council have applied their cartographic skills to make it a thing of beauty and function. It makes sense for them to use the same canvas in this public context but they need to meet the high expectations of users that base maps are super fast. They can do this by publishing their base map as a tiled service. They get the same great looking base map and the rapid delivery they are looking for.
With the LEP information though, this is more volatile data. Council want to be able to update on a frequent basis while it’s under review, and reflect those changes out to the public quickly. It makes sense to use a hosted feature service in this case. It’s a much smaller body of data that can be drawn quickly and when a web map is authored in ArcGIS Online using this service, information pop-ups can be configured to display the attributes associated with areas in the LEP to help users understand what they are looking at. Extending this thinking further, council could also use that same feature service to facilitate stakeholder feedback on the proposed plan.
Following that local government theme – here is an example of a tiled service and a feature service working together to deliver information about Heritage places in the area. The base map with the streets, lots, building footprints and water courses is a tiled service, the heritage places layer is a feature service.
So what’s different in this December 2012 release? Until now, the process of publishing a hosted tiled service (like the one in the example above) meant that the creation of tiles was carried out using ArcGIS Online resources and credits within your subscription. Now, there is a new option which means you can build the tiles using your own computing power. Instead of publishing the service direct to ArcGIS Online, you target the publishing operation to a Tile Package which creates a single .tpk file containing the tiles, the tiling scheme and additional metadata describing the contents. You can then load that .tpk file in to your ArcGIS Online account and generate a tiled service from it. Once loaded, the .tpk file can be removed and the service is running fully hosted.
The major win here is being able to use your own computing power to generate tiles if that makes sense. Taking a broader view of possibilities, the tile package created in this process is also something that all the ArcGIS Runtime SDKs understand.. For example a native iOS app built using the ArcGIS Runtime SDK for iOS knows how to make sense of a .tpk file and use it as a base map – same story for the SDKs for Android, Windows Phone, Windows, Java and WPF. It’s very convenient way of re-using the work put in to making a base map.
One thing that might save you some frustration if you want to explore this.. To enable the ability to specify a Tile Package as the target for a publish operation, you need to turn on the Enable ArcGIS Runtime options setting in ArcMap Options under the Sharing Tab as shown below.
Sharing & Subscriptions
A key piece of what ArcGIS Online is about is discovery and sharing, and this release includes some updates that will allow organisations to exercise finer control over the way they structure and populate groups, and expose items within groups.
Firstly, if you are building web maps that incorporate secure services from your ArcGIS Server for example, you now have the option to save credentials that allow access to the service in the map itself. Previously, the inclusion of a secured service would prompt the end-user for credentials when they opened the map. Clearly you still need to make sure only the people you want to access the map can do so, but for valid users, the end-user experience can now be much smoother.
Recognising the fact that you might well want to have users be part of a content group, but not necessarily want them to be able to modify or add content to that group, this release supports the notion of View-only groups. This type of group is a good way to share your authoritative maps and data to a targeted audience. You control what items appear in the group and who can view them. I see this as a pretty common use case – much more common than a group consisting of members all having permissions to contribute.
A couple of other features round off the sharing enhancements – when creating a new group, the ability to specify the field (Title, Owner, Rating, Views or Date), on which items in that group will be sorted and displayed can be specified. So for example, you might change it from most recently added (Date) to most popular (Rating). Lastly, group administrators in an organisation can now directly add users from their organisation to a group without going through the invite/confirm loop if they wish – again streamlining a process that would otherwise have involved several steps.
The final enhancement I want to cover off in this post relates to Printing. By default the Print button on a web map in the ArcGIS Online map viewer sends the request out to an ArcGIS Online server running a ArcGIS Server 10.1 Print service with a very simple layout. Now administrators can specify a similar Print Service running on their own ArcGIS Server and thus take advantage of their own custom layouts behind that service.
Whilst printing may not be the most exciting facet of the work we’re collectively involved in, I think this is a really important one and touches on a point I raised in my last post around flexibility and fidelity. If your organisation has a GIS team, and they’ve crafted layouts for printing at various sizes that incorporate your corporate style in legends, north arrows, disclaimers, colours etc, then you can leverage those resources with 100% fidelity throughout the ArcGIS Platform and print maps that looks the same regardless of whether they’re being originated on the desktop or the web.
The final part of this series of posts will look at the recent updates to ArcGIS Online in the area of Task Services along with some great new options for putting ArcGIS for Windows Mobile and ArcGIS Online to work together.