Chapter 2. Digging into the API

An Application Programming Interface (API) defines the operations, formats, and data structures available from a networked service. The developer writes code using the API to tell a server to accomplish a task. An API is built on top of an existing programming language, and uses the syntax and features of the language to make communications with a computer easier to code.

At one point, ESRI had three web-based APIs to communicate with ArcGIS Server: Flash, Silverlight, and JavaScript. With the rise of the mobile web and improvements in browsers, the ArcGIS JavaScript API won as the browser of choice. To make the best use of the ArcGIS Server map features, it's best to learn what's available from the JavaScript API. We're going to take a tour through the API, to become familiar with what it has to offer.

Unlike the other chapters in this book, this chapter provides more of a reference than a programming exercise. Short code snippets have been added to show how to use modules within the API. If you don't absorb every little crumb of information out of this chapter, don't worry. Just come back and reread parts of it for reference.

In this chapter, we'll learn about the following topics:

  • How maps are created and configured in the ArcGIS JavaScript API
  • How to display geographic data from ArcGIS Server through tiled, dynamic, and graphics layers
  • The building blocks of graphics on a map
  • How to communicate with ArcGIS Server services through tasks
  • How packaged UI controls called dijits can save development time

Note

For more information about the ArcGIS JavaScript API, including examples that you can build on your own, check out Building Web and Mobile ArcGIS Server Applications with JavaScript by Eric Pimpler or ArcGIS Web Development by Rene Rubalcava.