require the installation of a plugin for the application to be used in a browser. Flex and Silverlight both fall short as languages for mobile development and both require the use of a plugin for the application to run in a browser.
What this book covers
Chapter 2, Creating Maps and Adding Layers, teaches you how to create a map and add layers to the map. You will learn how to create an instance of the Map class, add layers of data to the map, and display this information on a web page. The Map class is the most fundamental class in the API as it provides the canvas for your data layers and any subsequent activities that occur in your application. However, your map is useless until you add layers of data. There are several types of data layers that can be added to a map, including tiled, dynamic, and feature. Readers will learn more about each of these layer types in this chapter.
Chapter 3, Adding Graphics to the Map, teaches the reader how to display temporary points, lines, and polygons in GraphicsLayer on the map. GraphicsLayer is a separate layer that always resides on top of other layers and stores all the graphics associated with the map.
Chapter 4, The Feature Layer, offers additional capabilities, apart from inheriting from GraphicsLayer, such as the ability to perform queries and selections. Feature layers are also used for online editing of features. Feature layers differ from tiled and dynamic map service layers, because feature layers bring geometry information to the client computer to be drawn and stored by the web browser. Feature layers
potentially cut down on round trips to the server. A client can request the features it needs, and perform selections and queries on those features without having to request more information from the server.
navigation and drawing toolbars.
Chapter 6, Performing Spatial and Attribute Queries, covers the ArcGIS Server Query Task, which allows you to perform attribute and spatial queries against data layers in a map service that have been exposed. You can also combine these query types to perform a combination attribute and spatial query.
Chapter 7, Identifying and Finding Features, covers two common operations found in any GIS application. These operations require that the user click a feature on the map in the case of identification, or perform a query in the case of finding features. In either case, information about particular features is returned. In this chapter, the reader will learn how to use the IdentifyTask and FindTask objects to obtain
information about features.
Chapter 8, Turning Addresses into Points and Points into Addresses, covers the use of the Locator task to perform geocoding and reverse geocoding. Geocoding is the process of assigning a coordinate to an address, while reverse geocoding assigns an address
to a coordinate.
Chapter 9, Network Analyst Tasks, allows you to perform analyses on street networks, such as finding the best route from one address to another, finding the closest school, identifying a service area around a location, or responding to a set of orders with a
fleet of service vehicles.
the built-in gesture support.
The last decade has seen a boom in people becoming acclimated to location technology. Most users may not fully realize that they’re using location technology when they get an alert on their phone that there’s traffic on the way home, or when they get a coupon from an app on their phone for a local restaurant. Smart phones are no longer simply devices for making phone calls, texting, and checking email. For many people, they’ve not only replaced the heavy and clumsy map book that your passenger used to help you navigate, but these “phones” have also replaced the expensive indash GPS systems in our vehicles. It’s so easy today to say the name of a store or venue into your phone, and in seconds receive turn-by-turn directions. That’s not to say that these directions may not try to direct you into a lake, but there’s no denying that location technology has become part of our daily lives. We gladly share our current locations with friends and family with as much fervor as when we shared a photo a few
years ago. Maps and the information they can convey are great tools that developers should take time to learn to use.
A few years ago, I was tasked with upgrading an enterprise GIS application and bringing it into the modern non-mainframe era. Esri had just started releasing Web APIs for use with their technology. At the time, I built my application with the Flex API, and I delved deep into the world of ActionScript and Flex modular development, but it always felt a bit heavy-handed.