MarkItUp

Virtual Earth is an Ajax solution that you can embed in your own applications to provide users with the ability to work with location-based data in a map environment.  Microsoft have used the Virtual Earth map (VEMap) to provide a solution that you can use out of the box over at Live Maps.

The Live Maps application is very rich and allows you to do many things.  Some of the features are intrinsic to the Virtual Earth map, and some are custom features that have been built into the application by the Live team.  The following graphic displays the Live Maps map with some of the features highlighted:

 

 

	Feature	VEMap/Live	Description
1	Search	Live	Saved locations can be searched for based on different collection types: Businesses, People, Locations.
2	Views	VEMap	VEMap provides API functions that allow you to toggle the view type of the map between road map view and satellite view.
3	Location Information	Live	A dialog allows you to enter descriptive information about each pin location that a user saves on the map.
4	Custom Collections	Live	When users save locations on the map they can save them against named favorite collections.  This makes it easy to create views of specific things, such as: My Friends, Our Work Locations.
5	Email	Live	The Live team have made it so that you can easily share information about places or favorite’d collections via email.
6	Smart navigation options	VEMap	Tools such as mini-map are built into the core VEMap API’s and provide users with tools that enable fast navigation.
7	Pins	Live and VEMap	Saved locations are represented as pins on the map.  VEMap provides these, but the Live application provides the logic for saving and retrieving them.

There are many more features that I haven’t mentioned here but you get the idea.  The important thing to realize here is that while some features are intrinsic to the VEMap control, others are provided by the application logic in the Live Maps application.  And therefore, if you wish to provide a custom map-based application, then you need to think about how you’ll implement the essential features on top of the VEMap.  The most fundamental of these are – location selection, persistence, and retrieval.  Without these 3 things you really don’t have much of a Virtual Earth based application at all.

At this time you might be thinking that, if the Live Maps implementation has so much functionality, then why would you want to roll your own solution?  I mean, it will allow you to create your own favorites and provide ways to maintain and share them.  Not only that, there’s many other more subtle features that have been implemented by the Live team.  An example of another feature is moving Pin locations.  The scenario here is that you’ve added a pin and then, for whatever reason, you need to move it slightly.  The Live Maps solution provides a few ways to move pins – version 6 even allows you to drag pins to another location to move them!  So, given that Live Maps offers all of this functionality, what more could you possibly want? 

Suppose that you need (or want) to provide a map-based solution that is totally tailored to a particular domain problem.  An example here might be that you are building an application for the local Education system.  In this case you might need to create an application with not only provides the core functions of VEMap, and the standard functions of Live, but also some other domain tools for doing school based searches or mapping particular geographies based on a custom set of wizards.  If this is the case, then you will need to provide your own custom solution.  This means:

• writing code to host the VEMap
• wiring up handlers to implement your own version of standard things such as:
• adding pins
• moving pins
• adding metadata to pins
• creating and maintaining favorite collections
• persisting and displaying pins

It’s a lot of responsibility to take on, but the result can be well worth it.  In coming articles, I’ll attempt to explain how to get up and running with your own map-based solution.  Initially we’ll look at some simple things – such as persisting and retrieving locations – and then we’ll head on through to some more advanced topics – such as clustering.